This frame, scattered with distant stars and galaxies, is a deep-field image taken using the Wide Field Imager (WFI), a camera mounted on the MPG/ESO 2.2-metre telescope located at the La Silla Observatory, Chile.

It was snapped as part of the COMBO-17 survey (Classifying Objects by Medium-Band Observations in 17 filters), a project that imaged five small patches of sky in 17 different coloured optical filters. The total area of sky explored in each of the COMBO-17 fields equates to approximately the same size as the full Moon, and has revealed huge numbers of distant objects — demonstrating just how much is still waiting to be discovered in our skies.

The image shows a region that was also investigated as part of the FORS Deep Field (FDF), a project that examined various areas of sky in great detail and depth using the FORS2 spectrograph instrument currently installed on ESO’s Very Large Telescope at the Paranal Observatory, Chile. However, these WFI images used many more filters than previous FDF observations, and looked at bigger patches of sky, resulting in images like the one above.

These small glimpses into the Universe have unveiled tens of thousands of distant stars, galaxies, and quasars previously hidden from our view, and have been used to investigate gravitational lensing and the distribution of dark matter in galaxies and clusters.

Links

• The COMBO-17 survey at the Max-Planck-Institut für Astronomie, Heidelberg

This new image, from ESO’s VISTA telescope, shows a newly-discovered brown dwarf nicknamed VVV BD001, which is located at the very centre of this zoomable image. It is the first new brown dwarf spotted in our cosmic neighbourhood as part of the VVV Survey. VVV BD001 is located about 55 light-years away from us, towards the very crowded centre of our galaxy.

Brown dwarfs are stars that never quite managed to grow up into a star like our Sun. They are often referred to as “failed stars”; they are larger in size than planets like Jupiter, but smaller than stars.

This dwarf is peculiar in two ways; firstly, it is the first one found towards the centre of our Milky Way, one of the most crowded regions of the sky. Secondly, it belongs to an unusual class of stars known as “unusually blue brown dwarfs” — it is still unclear why these stars are bluer than expected.

Brown dwarfs are born in the same way as stars, but do not have enough mass to trigger the burning of hydrogen to become normal stars. Because of this they are much cooler and produce far less light, making them harder to find. Astronomers generally look for these objects using near and mid-infrared cameras and special telescopes that are sensitive to these very cool objects, but usually avoid looking in very crowded regions of space — such as the central region of our galaxy, for example.

VISTA (the Visible and Infrared Survey Telescope for Astronomy) is the world’s largest survey telescope and is located at ESO’s Paranal Observatory in Chile. It is performing six separate surveys of the sky, and the VVV (VISTA Variables in the Via Lactea) survey is designed to catalogue a billion objects in the centre of our own Milky Way galaxy. VVV BD001 was discovered by chance during this survey.

Scientists have used the VVV catalogue to create a 3 dimensional map of the central bulge of the Milky Way (eso1339). The data have also been used to create a monumental 108 200 by 81 500 pixel colour image containing nearly nine billion pixels (eso1242), one of the biggest astronomical images ever produced.

Links

• VVV Survey (VISTA Variables in the Via Lactea)
• Research Paper

The small village of Toconao is the closest settlement to the largest astronomy project in existence, ALMA [1], the Atacama Large Millimeter/submillimeter Array. Toconao has less than 800 inhabitants and is located at 2475 metres above sea level in a natural oasis fed by a small mountain river on the outskirts of the driest desert in the world, the Atacama. The river doesn’t flow all year, but the local farmers have wisely built a network of dams and channels to regulate the flow of water so that they can have crops all year round.

When looking closely at this image, some buildings can be spotted, made of traditional materials such as adobe and volcanic rock, like the San Lucas Church and Bell Tower, on the bottom left of the image.

In parallel with their scientific work, ALMA staff have worked with the Atacameño Elders in Toconao and other areas to recover the vision of the Universe of their culture, aiming to preserve this cultural and scientific heritage for later generations.

ALMA has also been supporting an educational improvement plan at School E-21, a rural public education establishment in Toconao, since 2008. This plan, endorsed by the community, is focused on improving education in science and english.

This aerial image was taken by the two crew members of the ORA Wings for Science project, Clémentine Bacri and Adrien Normier, who flew a special eco-friendly ultralight aeroplane [2] on a year-long journey around the world to help out scientists, with aerial capabilities ranging from air sampling to archaeology, biodiversity observation and 3D terrain modelling.

ESO has an ongoing outreach partnership with this non-profit organisation. Short movies and amazing pictures that are produced during the flights will be used for educational purposes and for promoting local research. Their circumnavigation started in June 2012 and finished in June 2013 with a landing at the Paris Air Show.

Notes

[1] The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Southern Observatory (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

[2] The ultralight aircraft is a NASA-award winning Pipistrel Virus SW 80 using only 7 litres of fuel per 100 kilometres — less than most cars.

This spectacular aerial shot of Cerro Armazones, taken by ESO Photo Ambassador Gerhard Hüdepohl, represents that wonderful moment for a photographer: when everything lines up for the perfect shot.

Hüdepohl is also an electronics engineer at the European Southern Observatory’s Very Large Telescope (VLT) on Cerro Paranal, the world’s most advanced visible-light astronomical observatory and ESO’s flagship facility. Hüdepohl captured this image while on a commercial flight from Antofagasta to Santiago. Shortly after taking off the plane took the ideal flight path for an aerial snap of Cerro Armazones — and Hüdepohl could not have asked for better conditions. Seizing the moment, he was able to capture this unusual perspective, high above the spectacular terrain.

This image shows the Atacama Desert with amazing clarity, with the thin, zigzag path standing out sharply from the dusty terrain. This dirt road can be seen slicing its way up to the summit of Cerro Armazones. The site is currently occupied by a selection of surveying equipment, but it will soon become the home of the European Extremely Large Telescope (E-ELT), a 40-metre telescope that will not only answer existing questions in astronomy, but also raise — and hopefully answer — entirely new questions altogether.

Links

• ESO Photo Ambassadors

ESO's PESSTO survey has captured this view of Messier 74, a stunning spiral galaxy with well-defined whirling arms. However, the real subject of this image is the galaxy's brilliant new addition from late July 2013: a Type II supernova named SN2013ej that is visible as the brightest star at the bottom left of the image.

Such supernovae occur when the core of a massive star collapses due to its own gravity at the end of its life. This collapse results in a massive explosion that ejects material far into space. The resulting detonation can be more brilliant than the entire galaxy that hosts it and can be visible to observers for weeks, or even months.

PESSTO (Public ESO Spectroscopic Survey for Transient Objects) is designed to study objects that appear briefly in the night sky, such as supernovae. It does this by utilising a number of instruments on the NTT (New Technology Telescope), located at ESO's La Silla Observatory in Chile. This new picture of SN2013ej was obtained using the NTT during the course of this survey.

SN2013ej is the third supernova to have been observed in Messier 74 since the turn of the millennium, the other two being SN 2002ap and SN 2003gd. It was first reported on 25 July 2013 by the KAIT telescope team in California, and the first "precovery image" was taken by amateur astronomer Christina Feliciano, who used the public access SLOOH Space Camera to look at the region in the days and hours immediately before the explosion.

Messier 74, in the constellation of Pisces (The Fish), is one of the most difficult Messier objects for amateur astronomers to spot due to its low surface brightness, but SN2013ej should still be visible to careful amateur astronomers over the next few weeks as a faint and fading star.

Links

• PESSTO (the "Public ESO Spectroscopic Survey of Transient Objects")

This image, captured by ESO’s Very Large Telescope (VLT) at Paranal, shows a small part of the well-known emission nebula, NGC 6357, located some 8000 light-years away, in the tail of the southern constellation of Scorpius (The Scorpion). The image glows with the characteristic red of an H II region, and contains a large amount of ionised and excited hydrogen gas.

The cloud is bathed in intense ultraviolet radiation — mainly from the open star cluster Pismis 24, home to some massive, young, blue stars — which it re-emits as visible light, in this distinctive red hue.

The cluster itself is out of the field of view of this picture, its diffuse light seen illuminating the cloud on the centre-right of the image. We are looking at a close-up of the surrounding nebula, showing a mesh of gas, dark dust, and newly born and still forming stars.

A piercingly bright curtain of stars is the backdrop for this beautiful image taken by astronomer Håkon Dahle. The silhouetted figure in the foreground is Håkon himself surrounded by just a couple of the great dark domes that litter the mountain of ESO’s La Silla Observatory.

Many professional astronomers are also keen photographers — and who could blame them? ESO sites in the Atacama Desert are among the best places on Earth for observing the stars, and for the same reason, are amazing places for photographing the night sky.

Håkon took these photos while on a week-long observing run at the MPG/ESO 2.2 -telescope. During this time, the telescope was occasionally handed over to a different observing team, giving Håkon the opportunity to admire the starry night — as well as to capture it for the rest of us to see.

The Milky Way is brighter in the Southern Hemisphere than in the North, because of the way our planet’s southern regions point towards the dense galactic centre. But even in the South, the Milky Way in the night sky is quite faint in the sky. For most of us, light pollution from our cities and even the Moon can outshine the faint glow of the galaxy, hiding it from view.

One of the best aspects of La Silla Observatory is that it is far away from bright city lights, giving it some of the darkest night skies on Earth. The atmosphere is also very clear, so there is no haze to further muddy your vision. The skies at La Silla are so dark that it is possible to see a shadow cast by the light of the Milky Way alone.

Håkon submitted this photograph to the Your ESO Pictures Flickr group. The Flickr group is regularly reviewed and the best photos are selected to be featured in our popular Picture of the Week series, or in our gallery.

This beautiful image portrays the galaxies NGC 799 (below) and NGC 800 (above) located in the constellation of Cetus (The Whale). This pair of galaxies was first observed by the American astronomer Lewis Swift back in 1885.

Located at a distance of about 300 million light-years, our face-on view allows us to clearly appreciate their shapes. Like the Milky Way — our galaxy — these objects are both spiral galaxies, with characteristic long arms winding towards a bright bulge at the centre. In the prominent spiral arms, a large number of hot, young, blue stars are forming in clusters (tiny blue dots seen in the image) whereas in the central bulge a large group of cooler, redder, old stars are packed into a compact, almost spherical region.

At first glance, these galaxies look rather similar, but the devil is in the detail. Apart from the obvious difference in size, only NGC 799 has a bar structure, extending from its central bulge, and the spiral arms wind out from the ends of the bar. Galactic bars are thought to act as a mechanism that channels gas from the spiral arms to the centre, intensifying star formation. A supernova was also observed in NGC 799 in 2004, and was given the name SN2004dt.

Another interesting differentiating feature is the number of spiral arms. The small NGC 800 has three bright, knotty spiral arms, whilst NGC 799 only has two relatively dim, but broad spiral arms. These start at the end of the bar and wrap nearly completely around the galaxy forming a structure that looks almost like a ring.

While it might seem that this image depicts two impressive close spiral galaxies coexisting in an everlasting peace, nothing can be further than the truth. We could be just witnessing the calm before the storm. We don’t know exactly what the future will bring, but typically, when two galaxies are close enough, they interact over hundreds of millions of years by means of gravitational disturbances. In some cases, only minor interactions occur, causing shape distortions, but sometimes galaxies collide, merging to form a single, new and larger galaxy.

The image was obtained using the FORS1 instrument on the 8.2-metre ESO Very Large Telescope (VLT) atop Cerro Paranal, Chile. It combines exposures taken through three filters (B, V, R).

Five asteroids can also be seen — can you find them all? The asteroids moved between the different exposures leaving colourful streaks in the image.

This photo shows the view to the east from Paranal Observatory, seconds after the Sun has disappeared behind the horizon. The orange glow of the sunset can be seen against the 1.8-metre VLT Auxiliary Telescopes, and the almost full Moon is hanging in the sky. But the image is more interesting still, thanks to an atmospheric phenomenon known as the Belt of Venus.

The grey-bluish shadow above the horizon is the shadow of the Earth, and right above it is a pinkish glow. This phenomenon is produced by the reddened light of the setting Sun being backscattered by the Earth's atmosphere. As well as right after sunset, this atmospheric effect can also be seen shortly before sunrise. A very similar effect can also be observed during a total solar eclipse.

The telescopes shown in the image are three of the four 1.8-metre Auxiliary Telescopes, housed in ultra-compact mobile enclosures. These telescopes are dedicated to interferometric observations, when two or more telescopes work together, forming a virtual mirror and thus allowing astronomers to see much finer details than can be seen with the individual telescopes working independently.

Carolin Liefke took this photo during a visit to Paranal, and submitted it to the Your ESO Pictures Flickr group. The Flickr group is regularly reviewed and the best photos are selected to be featured in our popular Picture of the Week series, or in our gallery. Carolin works at the Haus der Astronomie (House of Astronomy) centre for astronomy education and outreach in Heidelberg, Germany, and is a member of the ESO Science Outreach Network (ESON). ESON brings ESO news to Member States and other countries by translating press releases and providing a point of contact for local media.

Links

• Haus der Astronomie
• Your ESO Pictures Flickr group
• ESO Science Outreach Network
• Carolin Liefke’s photostream
• This photo on Flickr

Spiral galaxies are usually very aesthetically appealing objects, and never more so than when they appear face-on. And this image is a particularly splendid example: it is the grand design spiral galaxy Messier 100, located in the southern part of the constellation of Coma Berenices, and lying about 55 million light-years from Earth.

While Messier 100 shows very well defined spiral arms, it also displays the faintest of bar-like structures in the centre, which classifies this as type SAB. Although it is not easily spotted in the image, scientists have been able to confirm the bar’s existence by observing it in other wavelengths.

This very detailed image shows the main features expected in a galaxy of this type: huge clouds of hydrogen gas, glowing in red patches when they re-emit the energy absorbed from newly born, massive stars; the uniform brightness of older, yellowish stars near the centre; and black shreds of dust weaving through the arms of the galaxy.

Messier 100 is one of the brightest members of the Virgo Cluster, which is the closest cluster of galaxies to our galaxy, the Milky Way, containing over 2000 galaxies, including spirals, ellipticals, and irregulars. This picture is a combination of images from the FORS instrument on ESO’s Very Large Telescope at Paranal Observatory in Chile, taken with red (R), green (V) and blue (B) filters.

Links

• Photos of the VLT

This dynamic image shows the New Technology Telescope (NTT) located at ESO’s La Silla Observatory in Chile. The distinctively shaped enclosure of the telescope appears blurred by movement in the picture, as the telescope rotates to point at its desired target. The photo was taken with a 30-second exposure.

One of the first things you notice in this picture is that the telescope building has a peculiar angular shape on the outside, rather than the more common rounded dome design usually seen. Its design features have been much copied, including by ESO’s Very Large Telescope, but they were groundbreaking when the telescope was inaugurated in 1989.

The NTT’s revolutionary design targets optimal image quality, for instance, through carefully controlled ventilation, which optimises airflow across the NTT, minimising the blurring caused by air turbulence inside. Just visible in the blur of this image are the large flaps that form a key part of this system.

Another feature that was advanced at the time of its construction is the NTT’s mirror. While, at 3.58 metres in diameter, it was never considered particularly large, its design was highly innovative. The mirror is flexible, and can be adjusted in real time to maintain a perfect shape, so no flexing or sagging can harm the image quality. ESO and the NTT were pioneers in using this technology, called active optics, and it is now a standard feature of modern telescopes.

Currently, the NTT has two different instruments that astronomers can use to conduct their observations: SOFI (short for the Son of ISAAC, a VLT  instrument), which is an infrared spectrograph and imaging camera, and EFOSC2, a spectrograph and camera designed to detect faint objects.

The La Silla Observatory is located in the southern part of the Atacama Desert, 600 kilometres north of Santiago de Chile and at an altitude of 2400 metres. 

The image was taken by Malte Tewes, an astronomer at the Ecole Polytechnique Fédérale de Lausanne, Switzerland.

Malte submitted this photograph to the Your ESO Pictures Flickr group. The Flickr group is regularly reviewed and the best photos are selected to be featured in our popular Picture of the Week series, or in our gallery.

Links

• Malte Tewes’ photostream
• This image on Flickr

This rare aerial view of the Paranal Observatory was taken in December 2012 by Clémentine Bacri and Adrien Normier, who are flying a special eco-friendly ultralight [1] aeroplane on a year-long journey around the world. This striking view shows the raw natural beauty of the landscape at the remote home of one of the world’s finest astronomical facilities, ESO’s Very Large Telescope (VLT), with its four independent 8.2-metre telescopes sitting at the top of Cerro Paranal.

ESO has an ongoing outreach partnership with the ORA Wings for Science project, a non-profit initiative which offers aerial support to public research organisations. The two crew members of the Wings for Science Project did a flyby above the observatories of Northern Chile, among other locations, before they left South America and jumped to Australia. During their trip, they help out scientists by providing aerial capabilities ranging from air sampling to archaeology, biodiversity observation and 3D terrain modelling.

The short movies and amazing pictures that are produced during the flights are used for educational purposes and for promoting local research. Their circumnavigation started in June 2012 and finished in June 2013 with a landing at the Paris Air Show on 17 June.

Notes

[1] The ultralight aircraft is a NASA-award winning Pipistrel Virus SW 80 using only 7 litres of fuel per 100 kilometres — less than most cars.

Links

• Wings for Science

Astronomy and telescopes can sometimes bring out our inner child. In a testament to human curiosity, astronomers keep building ever-larger instruments in remote places throughout the world.

ESO Astronomer Julien Girard snapped this cute picture of his daughter during a family day at Paranal Observatory, in the Chilean Andes. Thanks to a trick of perspective, little Maëlle seems to be looking into the open dome of one of the 1.8-metre Auxiliary Telescopes of ESO’s Very Large Telescope (VLT). Although the telescopes are used for serious scientific research, astronomers can sometimes feel like children when playing with such giant “toys”.

Julien Girard is an ESO astronomer and an ESO Photo Ambassador based in Chile, working at the VLT. He is the instrument scientist for the NACO adaptive optics instrument on the VLT’s Unit Telescope 4. He submitted this photograph to the Your ESO Pictures Flickr group, from where it was picked out as an ESO Picture of the Week.

Links

• ESO Photo Ambassadors
• Julien Girard’s Flickr photostream
• The “Your ESO Pictures” Flickr group
• The "Your ESO Pictures" announcement

In this photograph from 2012, we see antennas destined to become part of the Atacama Large Millimeter/submillimeter Array (ALMA). The three antennas in the foreground, as well as some of those in the background, were supplied by ESO as part of its contribution to ALMA, through a contract with the European AEM Consortium [1]. In total ESO is providing 25 of the 12-metre-diameter antennas. A further twenty-five 12-metre antennas are provided by the North American ALMA partner, while the remainder, a set of twelve 7-metre and four 12-metre antennas comprising the Atacama Compact Array, are provided by the East Asian ALMA partner.

The antennas are seen here at ALMA’s Operations Support Facility (OSF), at an altitude of 2900 metres in the foothills of the Chilean Andes. Those in the foreground are in the AEM Site Erection Facility, where the antennas are assembled and rigorously tested before they are handed over to the observatory. The antennas in the background have been handed over, and are undergoing further tests or having their sensitive receivers installed. Once the antennas are ready, they are transported to the Array Operations Site, on the Chajnantor Plateau at an altitude of 5000 metres. There, they join their counterparts as part of the ALMA array, working to study some of the deepest questions of our cosmic origins. Even once all the antennas are ready, the OSF will remain the centre of activities for the daily operation of ALMA, as a workplace for astronomers and the teams responsible for maintaining the observatory.

On the horizon is the Andes mountain range, the tallest peak belonging to the conical volcano, Licancabur. Licancabur marks the border between Chile and Bolivia and dominates the landscape of the area.

ALMA, an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

Notes

[1] The AEM Consortium is composed of Thales Alenia Space, European Industrial Engineering, and MT-Mechatronics.

Links

• More about ALMA at ESO
• Joint ALMA Observatory

What may look like a futuristic city out of a science fiction story, floating high above the clouds, is ESO’s longest-serving observatory, La Silla. This photograph was taken by astronomer Alan Fitzsimmons while standing near the ESO 3.6-metre telescope just after sunset. The Moon is located just outside the frame of this picture, bathing the observatory in an eerie light that is reflected off the clouds below.

The very faint band of glowing golden light just above the clouds still illuminated by the sunset is the zodiacal light. It is caused by sunlight diffused by dust particles between the Sun and the planets. This can only be seen just after sunset or just before sunrise, at particular times of year, from very good sites.

Several telescopes can be seen in this photograph. For example, the large angular structure at the end of the road is the New Technology Telescope (NTT). True to its name, when completed in 1989 the telescope included a number of revolutionary features including being the first to use full active optics as well as a revolutionary octagonal enclosure. Many of the NTT’s features went on to be incorporated into ESO’s Very Large Telescope.

The dome in the foreground, just to the right is the Swiss 1.2-metre Leonhard Euler Telescope named in honour of the famous Swiss mathematician Leonhard Euler (1707–83).

Alan submitted this photograph to the Your ESO Pictures Flickr group. The Flickr group is regularly reviewed and the best photos are selected to be featured in our popular Picture of the Week series, or in our gallery.

In this electrifying image, taken on Friday 7 June 2013, a furious thunderstorm is discharging its mighty rage over Cerro Paranal. The colossal enclosures of the four VLT Unit Telescopes, each one the size of an eight-storey building, are dwarfed under the hammering of the powerful storm.

In the left of the image, a solitary star has emerged to witness the show — a single point of light against an obscured sky. This star is Procyon, a bright binary star in the constellation of Canis Minor (The Lesser Dog).

Clouds over ESO’s Paranal Observatory are a rare sight. On average, the site experiences an astonishing 330 clear days every year. Lightning is even rarer, as the observatory is located in one of the driest places in the world: the Atacama Desert in Northern Chile, 2600 metres above sea level. If there are any clouds, most of the time the observatory stands above them.

Over a 16-year period working as an engineer on Paranal, ESO photo ambassador Gerhard Hüdepohl had seen lightning there just once before — so he grabbed his camera and ventured out into the elements to capture this unique sight.

An unusual new video sequence shows the rapid brightening and slower fading of a supernova explosion in the galaxy NGC 1365. The supernova, which has been named SN 2012fr, was discovered by French astronomer Alain Klotz on the 27 October 2012. The images captured by the small TAROT robotic telescope, located at ESO’s La Silla Observatory in Chile, have been compiled to create this unique movie.

Supernovae are the results of the explosive and cataclysmic deaths of certain types of stars. They are so brilliant that they can outshine their entire parent galaxy for many weeks before slowly fading from sight.

The supernova 2012fr [1] was discovered by Alain Klotz on the afternoon of 27 October 2012. He was busy measuring the brightness of a faint variable star in an image from the TAROT (Télescope à Action Rapide pour les Objets Transitoires) robotic telescope at ESO’s La Silla Observatory, when he noticed a new object that was not present in an image taken three days earlier. After checking with telescopes and astronomers all across the world the bright object was confirmed to be a Type Ia supernova.

Some stars co-habit with a second star, both orbiting around a common centre of gravity. In some cases one of them might be a very old white dwarf that is stealing material from its companion. At some point the white dwarf has siphoned off so much matter from its companion that it becomes unstable and explodes. This is known as a Type Ia supernova.

This kind of supernova has become very important as they are the most reliable way of measuring distances to very remote galaxies in the early Universe. Beyond the local group of galaxies, astronomers needed to find very bright objects with predictable properties that could act as signposts to help them map out the expansion history of the Universe. Type Ia supernovae are ideal as their brightnesses peak and fade in almost the same way for each explosion. Measurements of the distances to Type Ia supernovae led to the discovery of the accelerating expansion of the Universe, work that was awarded the Nobel Prize for Physics in 2011.

The host galaxy of this supernova is NGC 1365 (see also potw1037a), an elegant barred spiral galaxy, located 60 million light-years away towards the constellation of Fornax (The Furnace). With its diameter of about 200 000 light-years, it stands out among the other galaxies in the Fornax cluster. A colossal straight bar runs through the galaxy, containing the nucleus at the centre. The new supernova can be easily spotted just above the core, in the middle of the image.

Astronomers discovered more than 200 new supernovae in 2012, of which SN 2012fr is among the brightest. The supernova was first spotted when it was very faint on the 27 October 2012, and it reached its peak brightness on 11 November 2012 [2]. It was then easily seen as a faint star through a medium-sized amateur telescope. The video was compiled from a series of images taken of the galaxy over a period of three months, from the discovery in October until mid-January 2013.

TAROT is a 25-centimetre optical robotic telescope, able to move very fast, and to start an observation within a second. It was installed at La Silla Observatory in 2006 with the purpose of detecting cosmic gamma-ray bursts. The images that revealed SN 2012fr were captured using blue, green and red filters.

Notes

[1] Supernovae are designated by the year in which they are discovered, and the order in which they are discovered during that year, by using letters of the alphabet. The fact that the the supernova was discovered by a French team and it has been designated by the letters “fr” is pure coincidence.

[2] At this time it was magnitude 11.9. This is about 200 times too faint to see with the unaided eye even on a clear and dark night. But if the supernova at its peak brightness and our star the Sun were seen together at the same distance from the observer the supernova would appear about 3000 million times brighter than the Sun.

Links

• Video: TAROT discovers a bright supernova in NGC 1365
• Video: TAROT discovers a bright supernova in NGC 1365 (excerpt)

Contacts

Alain Klotz
Institut de Recherche en Astrophysique et Planetologie
Toulouse, France
Tel: +33 05 61 55 66 66
Email: alain.klotz@irap.omp.eu

Richard Hook
ESO, La Silla, Paranal, E-ELT & Survey Telescopes Press Officer
Garching bei München, Germany
Tel: +49 89 3200 6655
Cell: +49 151 1537 3591
Email: rhook@eso.org

It’s a real treat for photographers and astronomers alike: our skies are currently witnessing a phenomenon known as a syzygy — when three celestial bodies (or more) nearly align themselves in the sky. When celestial bodies have similar ecliptic longitude, this event is also known as a triple near-conjunction. Of course, this is just a trick of perspective, but this doesn't make it any less spectacular. In this case, these bodies are three planets, and the only thing needed to enjoy the show is a clear view of the sky at sunset.

Luckily, this is what happened for ESO photo ambassador Yuri Beletsky, who had the chance to spot this spectacular view from ESO's La Silla Observatory in northern Chile on Sunday 26 May. Above the round domes of the telescopes, three of the planets in our Solar System — Jupiter (top), Venus (lower left), and Mercury (lower right) — were revealed after sunset, engaged in their cosmic dance.

An alignment like this happens only once every few years. The last one took place in May 2011, and the next one will not be until October 2015. This celestial triangle was at its best over the last week of May, but you may still be able to catch a glimpse of the three planets as they form ever-changing arrangements during their journey across the sky.

Links

• Images
  • Three planets dance over La Silla (annotated)
  • Three people, three telescopes and three planets

At first sight, this mesmerising image might look like the waves caused by a stone thrown into a lake. And yet, this is the result of the apparent motion of the stars through the southern sky and some magic performed by the photographer. The image was taken at Cerro Armazones, a mountain peak 3060 metres above sea level, which lies in the central part of the Atacama Desert, in the Chilean Andes.

The long bright stripes are star trails and each one marks the path of a single star across the dark night sky. By leaving the camera’s shutter open for a long period of time, the movement of the stars, imperceptible to the naked eye, is revealed. Exposure times of as little as 15 minutes are long enough to do the trick. In this case, the photographer combined many shorter exposures to form the final image. The very wide-angle lens used for this series shows the celestial pole to the right, and the equator just above the short tower.

The amazingly large number of star trails in this picture also reveals the incredible quality of the night sky at Armazones: the atmosphere is extremely clear and there is no light pollution thanks to the mountaintop’s remote location. This is one of the reasons why this mountain was chosen to be the future home of the world’s biggest eye on the sky: the upcoming European Extremely Large Telescope (E-ELT).

It is difficult for even the most seasoned astronomer to resist taking time out of a busy observing schedule to stop and stare up at the gloriously rich southern sky. This image is a self portrait taken by astronomer Alan Fitzsimmons, who took this photo between observing sessions at ESO’s La Silla Observatory.

This bold photo shows the contrast between a simple, still and dark figure on Earth and the brilliant and bright starry night sky. In this picture, the sky is dominated by the enormous splash of stars and dust which make up the centre of the Milky Way, our home galaxy.

ESO’s observatories are located in the Atacama Desert in northern Chile, a region with very few inhabitants, which combines very dark nights with extremely clear atmospheric conditions, both factors conducive to making high quality observations.

La Silla is ESO’s first observatory. Inaugurated in 1969, it is home to a number of telescopes with mirror diameters of up to 3.6 metres. With more than 300 clear nights every year, La Silla is in an ideal position to house advanced observing instruments, but it also makes it a fabulous place to just stop and gaze up into the sky.

Alan submitted this photograph to the Your ESO Pictures Flickr group. The Flickr group is regularly reviewed and the best photos are selected to be featured in our Picture of the Week series or in our picture gallery.

In the outskirts of the Atacama Desert, far from the light-polluted cities of northern Chile, the skies are pitch-black after sunset. Such dark skies allow some of the best astronomical observing to take place — and at an altitude of 2400 metres, ESO’s La Silla Observatory has an incredibly clear view of the night sky. However, even such a remote, high, and dry location cannot always escape the weather that sometimes comes with the winter months, when blankets of snow can cover the mountain peak and its telescope domes.

This image shows a wintry La Silla sitting beneath a spray of stars from our Milky Way, the plane of which slants across the frame. Visible (from right to left) are the ESO 3.6-metre telescope, the 3.58-metre New Technology Telescope (NTT), the ESO 1-metre Schmidt telescope, and the MPG/ESO 2.2-metre telescope, which has snow on its dome. The small dome of the decommissioned Coudé Auxiliary Telescope can be seen adjacent to that of the ESO 3.6-metre telescope, and between it and the NTT are the water tanks of the observatory.

While the sight of snow at La Silla may initially be surprising, the high altitude ESO sites can experience both hot and cold temperatures through the year, and occasionally be subject to harsh conditions.

This photograph was taken by José Francisco Salgado, an ESO Photo Ambassador.

In this photograph one of the two ALMA transporters, Lore, is carrying one of the 7-metre-diameter antennas of ALMA, the Atacama Large Millimeter/submillimeter Array. Lore and her twin, Otto, are two bright yellow 28-wheeled vehicles, custom-built to move ALMA’s antennas around on the Chajnantor Plateau at an elevation of 5000 metres. By doing this, they can reconfigure the telescope array to make the most useful observations of a given target. They also move antennas between Chajnantor and the lower altitude Operations Support Facility for maintenance.

ALMA has a main array of fifty 12-metre-diameter antennas, and an additional array of twelve 7-metre antennas and four 12-metre antennas, known as the Atacama Compact Array (ACA). Lore is carrying one of the smaller, 7-metre antennas of the ACA. The 12-metre antennas of the main array cannot be placed closer than 15 metres apart as they would otherwise bump into each other. This minimum separation between antennas limits the maximum scale of the features that they can detect in the sky. This means that the main array cannot observe the broadest features of extended objects such as giant clouds of molecular gas in the Milky Way, or nearby galaxies. The ACA is specifically designed to help ALMA make better observations of these extended objects. Its smaller 7-metre antennas can be placed closer together, making them better able to measure the broader structures that the main array misses.

The dramatic icy spikes in the foreground are known as penitentes (Spanish for penitents). These are a curious natural phenomenon found in high altitude regions, typically more than 4000 metres above sea level. They are thin blades of hardened snow or ice which point towards the Sun, attaining heights from a few centimetres up to several metres.

ALMA, an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

Links

• More about ALMA at ESO
• Joint ALMA Observatory

This beautiful image, taken in December 2012, shows the array of antennas of the Atacama Large Millimeter/submillimeter Array (ALMA) [1], the largest astronomy project in existence, located at the Chajnantor Plateau in the Chilean Andes. The large antennas are 12 metres in diameter, and the smaller ones, gathered together in the middle of the image, form the ALMA Compact Array (ACA), which is made up of 12 antennas with a diameter of 7 metres. When the array is completed, there will be a total of 66 antennas.

ESO has initiated an outreach partnership with the ORA Wings for Science project, a non-profit organisation which offers aerial support to public research while on a year-long journey around the world. The two crew members of the Wings for Science Project, Clémentine Bacri and Adrien Normier, fly a special environmentally friendly ultralight [2] to help out scientists by providing aerial capabilities ranging from air sampling to archaeology, biodiversity observation and 3D terrain modelling.

The short movies and amazing pictures that are produced during the flights are used for educational purposes and for promoting local research. Their circumnavigation started in June 2012 and will finish in June 2013 with a landing at the Paris Air Show.

Notes

[1] The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Southern Observatory (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

[2] The ultralight aircraft is a NASA-award winning Pipistrel Virus SW 80 using only 7 litres of fuel per 100 kilometres — less than most cars.

Links

• Wings for Science

What might count as a beautifully clear day anywhere else in the world is actually an unusually cloudy day at ESO’s Paranal Observatory in the Atacama Desert. As this is one of the driest places on the planet, it is very uncommon to see clouds in the sky. Many astronomers and engineers who spend time at the site find the cloudless sky one of the most striking things about working in the Atacama Desert. This gorgeous 360-degree panoramic photo, taken by ESO contractor Dirk Essl in 15 separate exposures, has captured one of the rare days with clouds at Paranal. A few thin, wispy cirrus clouds can be seen above the enclosures of the Very Large Telescope. These clouds form at high altitudes and are made up of tiny ice crystals.

Paranal Observatory receives less than 10 millimetres of rainfall per year, which is just one of the reasons why this 2600-metre-high mountain was chosen as the site for ESO’s Very Large Telescope (VLT). This panorama includes the four large Unit Telescopes of the VLT as well as the four smaller Auxiliary Telescopes in their rounded enclosures, one in the foreground and the other three further away. The tracks on the ground are there so that the the Auxiliary Telescopes can be moved into different positions.

Dirk submitted this photograph to the Your ESO Pictures Flickr group. The Flickr group is regularly reviewed and the best photos are selected to be featured in our popular Picture of the Week series, or in our gallery.

Links

• This photograph on Dirk Essl’s Flickr photostream
• Dirk Essl’s Flickr photostream
• The “Your ESO Pictures” Flickr group
• The "Your ESO Pictures" announcement

This beautiful image of the Atacama Large Millimeter/submillimeter Array (ALMA), showing the telescope’s antennas under a breathtaking starry night sky, comes from Christoph Malin, an ESO Photo Ambassador. This is a still frame taken from one of his painstakingly created timelapse videos of ALMA, which are also available (see ann12099).

Located on the Chajnantor Plateau at an elevation of 5000 metres, ALMA is the world’s most powerful telescope for studying the Universe at submillimetre and millimetre wavelengths. Construction work for ALMA will be completed in 2013, and a total of 66 of these high-precision antennas will be operating on the site.

Glowing brightly in the sky, the Large and Small Magellanic Clouds stand out above the antennas. These nearby irregular dwarf galaxies are conspicuous objects in the southern hemisphere, even with the naked eye. These galaxies are both orbiting the Milky Way — our galaxy — and there is evidence that both have been greatly distorted by their interaction with the Milky Way as they travel close to it.
 
ALMA, an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

Links

• ALMA time-lapse compilation 2012 video
• More about ALMA at ESO
• Joint ALMA Observatory
• ESO Photo Ambassadors

This panoramic photograph, taken by Alexandre Santerne, shows an insider’s view of the disc of the Milky Way, our home galaxy, as well as a cold winter’s night, with a sprinkling of snow at ESO’s La Silla Observatory in Chile. From our vantage point within it, the disc of the Milky Way appears as a sparkling ribbon of stars stretching across the sky. In this panorama, the Milky Way is distorted into an arc by the wide-angle projection.

Peeking over the hill on the left of this photo is the ESO 3.6-metre telescope, home to the world's foremost exoplanet hunter, HARPS (the High Accuracy Radial velocity Planet Searcher). On the far right is the Swiss 1.2-metre Leonhard Euler Telescope, built and operated by the Geneva Observatory.

There are a number of reasons why La Silla is such an ideal location for observing the night sky in general, and the Milky Way in particular. Firstly, it’s located in the southern hemisphere, giving us a better view of the richer central region of the galaxy, and secondly, it’s located far from light and urban pollution, at an altitude of 2400 metres above sea level, making the nights dark and the atmosphere clear.

Alexandre submitted this photograph to the Your ESO Pictures Flickr group. The Flickr group is regularly reviewed and the best photos are selected to be featured in our popular Picture of the Week series, or in our gallery. Since submitting the photo, Alexandre has also become an ESO Photo Ambassador.

Links

• This photograph, with annotations, on Alexandre Santerne’s Flickr photostream
• Alexandre Santerne’s Flickr photostream
• The “Your ESO Pictures” Flickr group
• The "Your ESO Pictures" announcement
• ESO Photo Ambassadors

This image from ESO Photo Ambassador Farid Char, of the southern night sky over the Residencia “hotel” at ESO’s Paranal Observatory in Chile, presents a beautifully star-filled and dynamic view of the heavens.

To make the swirling star trails on this image, Farid used a 30-minute exposure to reveal the observed movement of the stars due to the rotation of the Earth. In the centre is the apparently still point of the south celestial pole. On the left, and at the top of the image, are the extended blurs of the Large and Small Magellanic Clouds, neighbouring galaxies of the Milky Way.

The dark glass dome below the circling stars is part of the roof of the Residencia building. This unique partially subterranean construction has been in use since 2002 by scientists and engineers working at the observatory. During the day, the 35-metre-wide dome allows natural daylight into the building.

At the observatory, located on a mountain at an elevation of 2600 metres in the arid Atacama Desert, the excellent astronomical conditions come at a price. People there face intense sunlight during the day, very low humidity, and the high altitude can leave them short of breath. To help them relax and rehydrate after long shifts on the mountaintop, there is an artificial oasis at the Residencia, with a small garden, a swimming pool that humidifies the air, a lounge, a dining room, and other recreational facilities. The building can accommodate over 100 people.

Links

• ESO Photo Ambassadors
• Farid Char’s homepage

This image depicts the galaxy NGC 4535, in the constellation of Virgo (The Maiden), on a beautiful background full of many distant faint galaxies. Its almost circular appearance shows that we observe it nearly face-on. In the centre of the galaxy, there is a well-defined bar structure, with dust lanes that curve sharply before the spiral arms break from the ends of the bar. The bluish colour of the spiral arms points to the presence of a large number of hot young stars. In the centre, however, older and cooler stars give the bulge of the galaxy a yellower appearance.

This visible image was made with the FORS1 instrument on ESO’s 8.2-metre Very Large Telescope. The galaxy can also be seen through smaller amateur telescopes, and was first observed by William Herschel in 1785. When seen through a smaller telescope, NGC 4535 has a hazy, ghostly appearance, which inspired the prominent amateur astronomer Leland S. Copeland to name it “The Lost Galaxy” in the 1950s.

NGC 4535 is one of the largest galaxies in the Virgo Cluster, a massive cluster of as many as 2000 galaxies, about 50 million light-years away. Although the Virgo Cluster is not much larger in diameter than the Local Group — the galaxy cluster to which the Milky Way belongs —  it contains almost fifty times as many galaxies.

Research telescopes sport state-of-the-art cameras which, together with the big mirrors needed for a large collecting area, allow astronomers to catch the faint light of deep sky objects. But you can also produce beautiful images without big telescopes and using more modest cameras.

Astrophotographers use more conventional cameras to capture images of astronomical objects, often on a larger scale than the observations made with big telescopes. Sometimes, they include the landscape in their composition, producing beautiful postcards of the Universe as seen from Earth.

For example, this Picture of the Week shows the 3.58-metre New Technology Telescope (NTT), located at ESO’s La Silla Observatory, and set against the starry background of the southern sky. Standing out in the image, the Milky Way — our home galaxy — can be seen as a hazy stripe across the sky. Dark regions within the Milky Way are areas where the light from background stars is blocked by interstellar dust. In addition, the Large Magellanic Cloud appears to the right of the telescope as a foggy blob in the sky. This nearby irregular galaxy is a conspicuous object in the southern sky. It orbits the Milky Way and there is evidence to suggest that it has been greatly distorted by its interaction with our own galaxy.

This image was taken by Håkon Dahle, who is also an accomplished professional astronomer. He submitted the photograph to the Your ESO Pictures Flickr group. The Flickr group is regularly reviewed and the best photos are selected to be featured in our popular Picture of the Week series, or in our gallery.

Links

• This photograph on Håkon Dahle’s Flickr photostream
• Håkon Dahle’s Flickr photostream
• The “Your ESO Pictures” Flickr group
• The "Your ESO Pictures" announcement

This impressive picture was taken on 5 March 2013 by Gabriel Brammer, one of the ESO Photo Ambassadors, and shows a sunset view of the Paranal Observatory, featuring two comets that are currently moving across the southern skies. Close to the horizon, on the right-hand side of the image, Comet C/2011 L4 (Pan-STARRS), the brightest of the two, shows a bright tail that is caused mainly by dust reflecting the sunlight. In the centre of the image, just above the right-hand slopes of Cerro Paranal, the greenish coma — a nebulous envelope around the nucleus — of Comet C/2012 F6 (Lemmon) can be distinguished, followed by a fainter tail. The green colour is a result of the ionisation of gases in the coma by sunlight. You might even be tricked into thinking that there is a third comet visible in this photo, but the bright object whizzing between comets Lemmon and Pan-STARRS is a serendipitous shooting star burning up in the atmosphere at just the right time and in the right place.

The Atacama Desert is one of the driest places in the world. Several factors contribute to its arid conditions. The magnificent Andes mountain range and the Chilean Coast Range block the clouds from the east and west, respectively. In addition, the cold offshore Humboldt Current in the Pacific Ocean, which creates a coastal inversion layer of cool air, hinders the formation of rain clouds. Moreover, a region of high pressure in the south-eastern Pacific Ocean creates circulating winds, forming an anticyclone, which also helps to keep the climate of the Atacama Desert dry. These arid conditions were a major factor for ESO in placing the Very Large Telescope (VLT) at Paranal, in the Atacama Desert. At the Paranal Observatory, located on the summit of Cerro Paranal, the precipitation levels are usually below ten millimetres per year, with the humidity often dropping below 10%. The observational conditions are excellent, with over 300 clear nights per year.

The splendid conditions for astronomical observations in the Atacama Desert are only rarely disturbed by the weather. However, for perhaps a couple of days each year, snow pays a visit to the Atacama Desert. This picture shows a beautiful panoramic view of Cerro Paranal. The VLT is on the peak on the left, and the VISTA survey telescope is on a slightly lower peak, a short distance to the right. The blue sky shows that this is yet another clear sunny day. This time, though, something is different: a thin dusting of snow has transformed the desert landscape, producing an unusual view of rare beauty.

This image was taken by ESO Photo Ambassador Stéphane Guisard on 1 August 2011.

Links

• More about the VLT at Paranal
• ESO Photo Ambassadors

Gerhard Hüdepohl, one of the ESO Photo Ambassadors, captured this spectacular image of ESO’s Very Large Telescope (VLT) during the testing of a new laser for the VLT 14 February 2013. It will be used as a vital part of the Laser Guide Star Facility (LGSF), which allows astronomers to correct for most of the disturbances caused by the constant movement of the atmosphere in order to create much sharper images. Nevertheless, is hard not to think of it as a futuristic laser cannon being pointed towards some kind of distant space invader.

As well as the amazing view of the Milky Way seen over the telescope, there is another feature making this picture even more special. To the right of the centre of the image, just below the Small Magellanic Cloud and almost hidden among the myriad stars seen in the dark Chilean sky, there is a green dot with a faint tail stretching to its left. This is the recently discovered and brighter-than-expected Comet Lemmon, which is currently moving slowly through the southern skies.

This remarkable deformable thin-shell mirror has been delivered to ESO at Garching, Germany and is shown undergoing tests. It is 1120 millimetres across but just 2 millimetres thick, making it much thinner than most glass windows. The mirror is very thin so that it is flexible enough for magnetic forces applied to it to alter the shape of its reflective surface. When in use, the mirror's surface will be constantly changed by tiny amounts to correct for the blurring effects of the Earth’s atmosphere and so create much sharper images.

The new deformable secondary mirror (DSM) will replace the current secondary in one of the VLT’s four Unit Telescopes. The entire secondary structure includes a set of 1170 actuators that apply a force on 1170 magnets glued to the back face of the thin shell. Sophisticated special-purpose electronics control the behaviour of the thin shell mirror. The reflecting surface can be deformed up to a thousand times per second by the action of the actuators.

The complete DSM system was delivered to ESO by the Italian companies Microgate and ADS in December 2012 and concludes eight years of sustained development efforts and manufacturing. This is the largest deformable mirror ever produced for astronomical purposes and is the latest of a long line of such mirrors. The extensive experience of these contractors shows in the high performance of the system and its reliability. The installation on the VLT is scheduled to start in 2015.

The shell mirror (ann12015) itself was manufactured by the French company REOSC. It is a sheet of ceramic material that has been polished to a very accurate shape. The manufacturing process starts with a block of Zerodur ceramic, provided by Schott Glass (Germany) that is more than 70 millimetres thick. Most of this material is ground away to create the final thin shell that must be carefully supported at all times as it is extremely fragile.

Links

• The Adaptive Optics Department at ESO
• Booklet on the Adaptive Optics Facility (AOF) at ESO (PDF file)
• Microgate
• ADS
• REOSC
• Schott Glass

On a clear night in Bavaria, ESO staff attended the filming of an ESOcast episode focusing on ESO’s new compact laser guide star unit, seen here in action at the Allgäu Public Observatory in Ottobeuren, Germany. Using the glow from their mobile phones, staff took advantage of the long-exposure photograph to draw the letters “ESO” in light, while standing in front of the observatory. Just left of the vertical laser beam, the Milky Way can be seen. Just above the horizon over the observatory, the dotted tracks of aircraft can be seen in the distance. The laser has a powerful beam of 20 watts, and to protect pilots and passengers a no-fly zone around the observatory was created by the Deutsche Flugsicherung (responsible for air traffic control in Germany) during the nighttime observing hours.

Laser guide stars are artificial stars created in the Earth’s atmosphere using a laser beam. The laser makes the sodium atoms in a layer 90 kilometres up in the atmosphere glow and so creates an artificial star in the sky that can be observed by a telescope. Using measurements of the artificial star, adaptive optics instruments can then correct the blurring effect of the atmosphere in the observations.

ESO’s innovative concept uses a powerful laser whose beam is launched with a small telescope, combined into a single modular unit which can be mounted directly on a large telescope. The concept, which has been patented and licensed by ESO, will be used to provide the Very Large Telescope (VLT) with four similar laser units. It will also play a key role in the units that will equip the future European Extremely Large Telescope (E-ELT).

At the time of filming, the unit was undergoing testing before being shipped to the ESO Paranal Observatory in Chile, home of the VLT.

Links

• ESOcast episode on Laser Guide Stars
• More about the ESO Wendelstein Laser Guide Star unit
• More about the Allgäu Public Observatory

Babak Tafreshi, an ESO Photo Ambassador, has captured a beautiful image of ESO’s Paranal Observatory illuminated by the sunset. The beautifully clear sky hints at the exceptional atmospheric conditions here; one major reason why ESO chose Paranal as the site of the Very Large Telescope (VLT), its flagship facility.

The VLT — which can be seen on Cerro Paranal, the highest peak in the image, with an altitude of 2600 metres —  is the world’s most advanced visible-light astronomical observatory. It consists of four Unit Telescopes, each with a primary mirror 8.2 metres across, and four 1.8-metre Auxiliary Telescope.. The VLT operates at visible and infrared wavelengths and among the pioneering observations carried out using the VLT have been the first direct image of an exoplanet (see eso0515) and the tracking of stars orbiting the Milky Way’s central black hole (see eso0846 and eso1151).

Also on Cerro Paranal is the VLT Survey Telescope (VST). Its smaller enclosure can just be made out in front of one of the larger VLT Unit Telescope enclosures on the mountaintop. The VST is the most recent addition to Paranal, with the first images released in 2011 (see eso1119). It sports a primary mirror 2.6 metres across, which makes it the largest telescope in the world designed for surveying the sky in visible light.

Another survey telescope at the Paranal Observatory is VISTA, the Visible and Infrared Survey Telescope for Astronomy, which can be seen on another peak, in the foreground of Cerro Paranal. VISTA is the world’s largest survey telescope, with a 4.1-metre mirror, and operates at near-infrared wavelengths. The telescope started work in 2009 (see eso0949).

Links

• More about the Very Large Telescope
• More about the survey telescopes at Paranal
• ESO Photo Ambassadors

This deep-field image shows what is known as a supercluster of galaxies — a giant group of galaxy clusters which are themselves clustered together. This one, known as Abell 901/902, comprises three separate main clusters and a number of filaments of galaxies, typical of such super-structures. One cluster, Abell 901a, can be seen above and just to the right of the prominent red foreground star near the middle of the image. Another, Abell 901b, is further to the right of Abell 901a, and slightly lower. Finally, the cluster Abell 902 is directly below the red star, towards the bottom of the image.

The Abell 901/902 supercluster is located a little over two billion light-years from Earth, and contains hundreds of galaxies in a region about 16 million light-years across. For comparison, the Local Group of galaxies — which contains our Milky Way among more than 50 others — measures roughly ten million light-years across.

This image was taken by the Wide Field Imager (WFI) camera on the MPG/ESO 2.2-metre telescope, located at the La Silla Observatory in Chile. Using data from the WFI and from the NASA/ESA Hubble Space Telescope, in 2008 astronomers were able to precisely map the distribution of dark matter in the supercluster, showing that the clusters and individual galaxies which comprise the super-structure reside within vast clumps of dark matter. To do this, astronomers looked at how the light from 60 000 faraway galaxies located behind the supercluster was being distorted by the gravitational influence of the dark matter it contains, thus revealing its distribution. The mass of the four main dark matter clumps of Abell 901/902 is thought to be around ten trillion times that of the Sun.

The observations shown here are part of the COMBO-17 survey, a survey of the sky undertaken in 17 different optical filters using the WFI camera. The COMBO-17 project has so far found over 25 000 galaxies.

Links

• The COMBO-17 survey at the Max-Planck-Institut für Astronomie, Heidelberg
• A wider-field view of the area around the Abell 901/902 supercluster

Another starry night on the Chajnantor Plateau in the Chilean Andes. The first quarter Moon glows brightly in this exposure, outshining the surrounding celestial objects. However, for radio telescopes such as APEX (the Atacama Pathfinder Experiment), seen here, the brightness of the Moon is not a problem for observations. In fact, since the Sun itself is not too bright at radio wavelengths, and these wavelengths do not brighten the sky in the same way, this telescope can even be used during the daytime, as long as it is not pointed towards the Sun.

APEX is a 12-metre-diameter telescope that observes light at millimetre and submillimetre wavelengths. Astronomers observing with APEX can see phenomena which would be invisible at the shorter wavelengths of infrared or visible light. For instance, APEX can peer through dense interstellar clouds of gas and cosmic dust, revealing hidden regions of ongoing star formation which glow brightly at these wavelengths, but which may be obscured and dark in visible and infrared light. Some of the earliest and most distant galaxies are also excellent targets for APEX. Due to the expansion of the Universe over many billions of years, their light has been redshifted into APEX’s millimetre and submillimetre range.

APEX is a collaboration between the Max Planck Institute for Radio Astronomy (MPIfR), the Onsala Space Observatory (OSO) and ESO. Operation of APEX at Chajnantor is entrusted to ESO.

This stunning picture was taken by ESO Photo Ambassador Babak Tafreshi. It is part of a larger image, which is also available cropped in a different way.

Links

• More about APEX at ESO
• ESO Photo Ambassadors

At first glance, this view shows the mountainous scenery of Chile’s Chajnantor Plateau, with snow and ice scattered over the barren terrain. The main peaks from right to left are Cerro Chajnantor, Cerro Toco, Juriques, and the distinctive conical volcano Licancabur (see potw1240) —  impressive enough! However, the true stars of the picture are the tiny, barely visible structures in the very centre of the image — perceptible if you squint hard enough.

These structures, dwarfed by their mountainous neighbours, are the antennas that form the Atacama Large Millimeter/submillimeter Array (ALMA), a large radio telescope. While it may appear minute in this image, the array is actually composed of a collection of large 12- and 7-metre-diameter antennas, and when it’s complete, there will be a total of 66 of them, spread over distances of up to 16 kilometres across the plateau. Construction work for ALMA is expected to finish in 2013, but the telescope has begun the initial phase of Early Science observations, already returning incredible results (see for example eso1239). Since this photograph was taken, many more antennas have joined the array on the plateau.

ALMA, an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

Links

• More about ALMA at ESO
• Joint ALMA Observatory

This view shows one of the Unit Telescopes of ESO’s Very Large Telescope (VLT) sitting beneath bright star trails circling the south celestial pole, a point in the sky that lies in the southern constellation of Octans (The Octant). These trails are arcs of light that trace out a star’s observed movement across the sky as the Earth slowly rotates. To capture these star trails on camera, many exposures were taken over time and combined to give the final appearance of circular tracks.

Illuminated by moonlight, the telescope in the foreground is just one of the four Unit Telescopes (UTs) that make up the VLT at Paranal, Chile. Following the inauguration of the Paranal site in 1999, each UT was named in the language of the native Mapuche tribe. The names of the UTs — Antu, Kueyen, Melipal, and Yepun — represent four prominent and beautiful features of the sky: the Sun, the Moon, the constellation of the Southern Cross, and Venus, respectively. The UT in this photograph is Yepun, also known as UT4.

This image was taken by ESO Photo Ambassador Farid Char. Char works at ESO’s La Silla–Paranal Observatory, and is a member of the site-testing team for the European Extremely Large Telescope (E-ELT), a new ground-based telescope that will be the largest optical/near-infrared telescope in the world when it is completed in the early 2020s.

Links

• More about the Very Large Telescope
• ESO Photo Ambassador

Babak Tafreshi, one of the ESO Photo Ambassadors, has captured the antennas of the Atacama Large Millimeter/submillimeter Array (ALMA) under the southern sky in another breathtaking image.

The dramatic whorls of stars in the sky are reminiscent of van Gogh’s Starry Night, or — for science fiction fans — perhaps the view from a spacecraft about to enter hyperspace. In reality, though, they show the rotation of the Earth, revealed by the photograph’s long exposure. In the southern hemisphere, as the Earth turns, the stars appear to move in circles around the south celestial pole, which lies in the dim constellation of Octans (The Octant), between the more famous Southern Cross and the Magellanic Clouds. With a long enough exposure, the stars mark out circular trails as they move.

The photograph was taken on the Chajnantor Plateau, at an altitude of 5000 metres in the Chilean Andes. This is the site of the ALMA telescope, whose antennas can be seen in the foreground. ALMA is the most powerful telescope for observing the cool Universe — molecular gas and dust, as well as the relic radiation of the Big Bang. When ALMA construction is complete in 2013, the telescope will have 54 of these 12-metre-diameter antennas, and twelve 7-metre antennas. However, early scientific observations with a partial array already began in 2011. Even though it is not fully constructed, the telescope is already producing outstanding results, outperforming all other telescopes of its kind. Some of the antennas are blurred in the photograph, as the telescope was in operation and moving during the shot.

ALMA, an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

Links

• More about ALMA at ESO
• Joint ALMA Observatory
• ESO Photo Ambassadors

This panoramic view of the Chajnantor Plateau shows the site of the Atacama Large Millimeter/submillimeter Array (ALMA), taken from near the peak of Cerro Chico. Babak Tafreshi, an ESO Photo Ambassador, has succeeded in capturing the feeling of solitude experienced at the ALMA site, 5000 metres above sea level in the Chilean Andes. Light and shadow paint the landscape, enhancing the otherworldly appearance of the terrain. In the foreground of the image, clustered ALMA antennas look like a crowd of strange, robotic visitors to the plateau. When the telescope is completed in 2013, there will be a total of 66 such antennas in the array, operating together.

ALMA is already revolutionising how astronomers study the Universe at millimetre and submillimetre wavelengths. Even with a partial array of antennas, ALMA is more powerful than any previous telescope at these wavelengths, giving astronomers an unprecedented capability to study the cool Universe — molecular gas and dust as well as the relic radiation of the Big Bang. ALMA studies the building blocks of stars, planetary systems, galaxies, and life itself. By providing scientists with detailed images of stars and planets being born in gas clouds near the Solar System, and detecting distant galaxies forming at the edge of the observable Universe, which we see as they were roughly ten billion years ago, it will let astronomers address some of the deepest questions of our cosmic origins.

ALMA, an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

Links

• More about ALMA at ESO
• Joint ALMA Observatory
• ESO Photo Ambassadors

ESO Photo Ambassador, Babak Tafreshi has taken another outstanding panoramic photograph of ESO’s Paranal Observatory.

In the foreground is the dramatic, mountainous landscape of the Atacama Desert. On the left, on the highest peak, is the ESO Very Large Telescope (VLT), and in front of it, on a slightly lower peak, is the VISTA telescope (Visible and Infrared Survey Telescope for Astronomy).

In the background, the sunrise colours Paranal’s sky with a beautiful pastel palette. Extending beyond the horizon, the sea of clouds over the Pacific Ocean — which lies only 12 kilometres from Paranal — is visible.

Above the horizon, where the sea of clouds meets the sky, a dark band can be seen. This dark band is the Earth’s shadow, cast by the planet onto its atmosphere. This phenomenon can sometimes be seen around the times of sunset and sunrise, if the sky is clear and the horizon is unobstructed — conditions that are certainly met in Paranal Observatory. Above the Earth’s shadow is a pinkish glow known as the Belt of Venus. It is caused by light from the rising (in this case) or setting Sun being scattered by the Earth’s atmosphere.

Links

• ESO Photo Ambassadors

Although this image might at first look like abstract modern art, it is in fact the result of a long camera exposure of the night sky over the Chajnantor Plateau in the Chilean Andes. As the Earth rotates towards another day, the stars of the Milky Way above the desert stretch into colourful streaks. The high-tech telescope in the foreground, meanwhile, takes on a dreamlike quality.

This mesmerising photo was taken 5000 metres above sea level on the Chajnantor Plateau, home of the Atacama Pathfinder Experiment (APEX) telescope, which is seen here. APEX is a 12-metre-diameter telescope which collects light with wavelengths in the millimetre and submillimetre range. Astronomers use APEX to study objects ranging from the cold clouds of gas and cosmic dust where new stars are being born, to some of the earliest and most distant galaxies in the Universe.

APEX is a pathfinder for the Atacama Large  Millimeter/submillimeter Array (ALMA), a revolutionary telescope that ESO, together with its international partners, is building and operating, also on the Chajnantor Plateau. When ALMA is completed in 2013, it will be an array of 54 antennas with 12-metre diameters, and an additional 12 antennas with 7-metre diameters. The two telescopes are complementary: thanks to its larger field of view, APEX can find many targets across wide areas of sky, which ALMA will study in great detail due to its far higher angular resolution. APEX and ALMA are both important tools to help astronomers find out more about the workings of our Universe, such as the formation of the stars seen wheeling overhead in this image.

ESO Photo Ambassador Babak Tafreshi took this picture. He is also founder of The World At Night, a programme to create and exhibit a collection of stunning photographs and time-lapse videos of the world’s most beautiful and historic sites against a nighttime backdrop of stars, planets and celestial events.

APEX is a collaboration between the Max Planck Institute for Radio Astronomy (MPIfR), the Onsala Space Observatory (OSO) and ESO. Operation of APEX at Chajnantor is entrusted to ESO. ALMA is an international astronomy facility, and a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ESO is the European partner in ALMA.

Links

• More about APEX at ESO
• ESO Photo Ambassadors

For centuries, philosophers and scientists have wondered about the possibility of habitable planets outside the Solar System. Today, this idea is more than speculation: many hundreds of exoplanets have been discovered over the last couple of decades, by astronomers all over the world. Various different techniques are used in this search for new worlds. In this unusual photograph, telescopes using two of these methods, the ESO 3.6-metre telescope with the HARPS spectrograph, and the space telescope CoRoT, have been captured in the same shot. The photograph was taken by Alexandre Santerne, an astronomer who studies exoplanets himself.

The High Accuracy Radial velocity Planetary Search (HARPS) spectrograph, the world’s foremost exoplanet hunter, is an instrument on ESO’s 3.6-metre telescope. The open dome of this telescope can be seen on the left of this image, behind the angular enclosure of the New Technology Telescope. HARPS finds exoplanets by detecting small changes in the motion of a star as it wobbles slightly under the gravitational pull of the orbiting planet. This is known as the radial velocity technique for finding exoplanets.

The faint trail of light high in the sky in this 20-second exposure is not a meteor but CoRoT, the Convection Rotation and planetary Transits space telescope. CoRoT searches for planets by looking for the dimming of light from a star which occurs when a planet passes in front of it — the transit method. The space telescope’s location above the Earth’s atmosphere improves the accuracy of its observations by removing the twinkling of stars. Potential planets found by the transit method are confirmed using complementary techniques such as the radial velocity method. Indeed, on very the night that this photograph was taken, HARPS was being used to follow up exoplanet candidates detected by CoRoT!

In November 2012, CoRoT unfortunately suffered a computer problem, meaning that — although it is still functioning — it can no longer retrieve data from its telescope (see the news on the CoRoT website, or for example this Nature News article). The CoRoT team have not given up though, and are working to revive the systems. Whether or not CoRoT can be revived, there is certainly no doubt that the mission has already been a great success! The spacecraft has doubled its originally planned mission lifetime, and was the first spacecraft to discover an exoplanet using the transit method. CoRoT has made great contributions, both to the search for exoplanets, and to the study of the interiors of stars through the field of asteroseismology.

The search for exoplanets helps us understand our own planetary system, and may be the first step towards finding life beyond Earth. HARPS and CoRoT are just two of the many exciting instruments developed to assist astronomers with this search.

Alexandre submitted this photograph to the Your ESO Pictures Flickr group. The Flickr group is regularly reviewed and the best photos are selected to be featured in our popular Picture of the Week series, or in our gallery. In 2012, as part of ESO’s 50th anniversary year, we are also welcoming your historical ESO-related images. Since submitting the photo, Alexandre has also become an ESO Photo Ambassador.

Links

• This photograph, with annotations, on Alexandre Santerne’s Flickr photostream
• Alexandre Santerne’s Flickr photostream
• The “Your ESO Pictures” Flickr group
• The "Your ESO Pictures" announcement
• ESO Photo Ambassadors

The Atacama Pathfinder Experiment (APEX) telescope — captured in this dramatic image taken by ESO Photo Ambassador Babak Tafreshi — is one of the tools used by ESO to peer beyond the realm of visible light. It is located on the Chajnantor Plateau at an altitude of 5000 metres.

Clusters of white penitentes can be seen in the foreground of the photograph. The penitentes (Spanish for penitents) are a curious natural phenomenon found in high altitude regions, typically more than 4000 metres above sea level. They are thin spikes of hardened snow or ice, with their blades pointing towards the Sun, attaining heights from a few centimetres up to several metres.

APEX is a 12-metre-diameter telescope that observes light at millimetre and submillimetre wavelengths. Astronomers observing with APEX can see phenomena which would be invisible at shorter wavelengths. The telescope enables them to study molecular clouds — the dense regions of gas and cosmic dust where new stars are being born — which are dark and obscured by dust in visible or infrared light, but which glow brightly at these relatively longer wavelengths. Astronomers use this light to study their chemical and physical conditions. This wavelength range is also ideal for studying some of the earliest and most distant galaxies in the Universe.

Just visible in the night sky above and to the left of APEX are, respectively, the faint smudges of the Small and Large Magellanic Clouds, neighbouring galaxies of our own Milky Way galaxy. The plane of the Milky Way itself can be seen as a hazy band across the sky, most prominently over the APEX control building on the right. Dark patches in the band are regions where light from distant stars is blocked by interstellar dust. Hidden behind these dark dust lanes, the centre of the Milky Way lies at a distance of about 27 000 light-years. Telescopes such as APEX are a crucial tool for astronomers to peer through the dust and study the centre of our galaxy in detail.

APEX is a collaboration between the Max Planck Institute for Radio Astronomy (MPIfR), the Onsala Space Observatory (OSO) and ESO. Operation of APEX at Chajnantor is entrusted to ESO.

Links

• More about APEX at ESO
• ESO Photo Ambassadors

ESO Photo Ambassador, Babak Tafreshi has captured an outstanding image of the sky over ESO’s Paranal Observatory, with a treasury of deep-sky objects.

The most obvious of these is the Carina Nebula, glowing intensely red in the middle of the image.  The Carina Nebula lies in the constellation of Carina (The Keel), about 7500 light-years from Earth. This cloud of glowing gas and dust is the brightest nebula in the sky and contains several of the brightest and most massive stars known in the Milky Way, such as Eta Carinae. The Carina Nebula is a perfect test-bed for astronomers to unveil the mysteries of the violent birth and death of massive stars. For some beautiful recent images of the Carina Nebula from ESO, see eso1208, eso1145, and eso1031.

Below the Carina Nebula, we see the Wishing Well Cluster (NGC 3532). This open cluster of young stars was named because, through a telescope’s eyepiece, it looks like a handful of silver coins twinkling at the bottom of a wishing well. Further to the right, we find the Lambda Centauri Nebula (IC 2944), a cloud of glowing hydrogen and newborn stars which is sometimes nicknamed the Running Chicken Nebula, from a bird-like shape that some people see in its brightest region (see eso1135). Above this nebula and slightly to the left we find the Southern Pleiades (IC 2632), an open cluster of stars that is similar to its more familiar northern namesake.

In the foreground, we see three of the four Auxiliary Telescopes (ATs) of the Very Large Telescope Interferometer (VLTI). Using the VLTI, the ATs — or the VLT’s 8.2-metre Unit Telescopes — can be used together as a single giant telescope which can see finer details than would be possible with the individual telescopes. The VLTI has been used for a broad range of research including the study of circumstellar discs around young stellar objects and of active galactic nuclei, one of the most energetic and mysterious phenomena in the Universe.

Links

• ESO Photo Ambassadors

This beautiful panoramic picture taken by Babak Tafreshi, an ESO Photo Ambassador, shows the last rays of sunlight bathing the Chajnantor Plateau in Chile’s Atacama region. The plateau is the home of the Atacama Pathfinder Experiment (APEX) telescope, which can be seen on the left of the panorama. From this remote place on Earth, 5000 metres above sea level, APEX studies the “cold Universe”.

APEX is a 12-metre-diameter telescope that observes light at millimetre and submillimetre wavelengths. Astronomers observing with APEX can see phenomena which would be invisible at shorter wavelengths. The telescope enables them to study molecular clouds — the dense regions of gas and cosmic dust where new stars are being born — which are dark and obscured by dust in visible or infrared light, but which glow brightly at these relatively longer wavelengths. Astronomers use this light to study the chemical and physical conditions in the clouds. This wavelength range is also ideal for studying some of the earliest and most distant galaxies in the Universe.

Since it began operating in 2005, APEX has produced many important science results. For example, APEX teamed up with ESO’s Very Large Telescope to detect matter being torn apart by the black hole at the centre of the Milky Way (eso0841), a result counted among the ESO Top 10 Astronomical Discoveries.

Clusters of white penitentes can be seen on the ground around APEX. The penitentes (Spanish for penitents) are a curious natural phenomenon found in high-altitude regions, typically more than 4000 metres above sea level. They are thin spikes of hardened snow or ice, with their blades pointing towards the Sun, attaining heights from a few centimetres up to several metres.

APEX is a collaboration between the Max Planck Institute for Radio Astronomy (MPIfR), the Onsala Space Observatory (OSO) and ESO. Operation of APEX at Chajnantor is entrusted to ESO.

APEX’s 12-metre dish is based on a prototype antenna for another observatory on Chajnantor, the Atacama Large Millimeter/submillimeter Array (ALMA). ALMA will have an array of fifty-four 12-metre antennas and twelve 7-metre antennas, when it is completed in 2013. ESO is the European partner in this international astronomy facility, which is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile.

Links

• More about APEX at ESO
• ESO Photo Ambassadors

IC 5148 is a beautiful planetary nebula located some 3000 light-years away in the constellation of Grus (The Crane). The nebula has a diameter of a couple of light-years, and it is still growing at over 50 kilometres per second — one of the fastest expanding planetary nebulae known. The term “planetary nebula” arose in the 19th century, when the first observations of such objects — through the small telescopes available at the time — looked somewhat like giant planets. However, the true nature of planetary nebulae is quite different.

When a star with a mass similar to or a few times more than that of our Sun approaches the end of its life, its outer layers are thrown off into space. The expanding gas is illuminated by the hot remaining core of the star at the centre, forming the planetary nebula, which often takes on a beautiful, glowing shape. 

When observed with a smaller amateur telescope, this particular planetary nebula shows up as a ring of material, with the star — which will cool to become a white dwarf — shining in the middle of the central hole. This appearance led astronomers to nickname IC 5148 the Spare Tyre Nebula.

The ESO Faint Object Spectrograph and Camera (EFOSC2) on the New Technology Telescope at La Silla gives a somewhat more elegant view of this object. Rather than looking like a spare tyre, the nebula resembles ethereal blossom with layered petals.

ESO’s Paranal Observatory — located in Chile’s Atacama region — is most well known for the Very Large Telescope (VLT), ESO’s flagship telescope facility. However, over the last few years, the site has also become home to two state-of-the-art survey telescopes. These new members of the Paranal family are designed to image large areas of the sky quickly and deeply.

One of them, the 4.1-metre Visible and Infrared Survey Telescope for Astronomy (VISTA), is located on a neighbouring peak not far from the Paranal summit. It is shown in this beautiful photograph taken from Paranal by ESO Photo Ambassador, Babak Tafreshi. VISTA is the world’s largest survey telescope, and has been operating since December 2009.

At the lower right corner of the image, VISTA’s enclosure appears in front of a seemingly endless mountain range, which stretches to the horizon. As sunset approaches, the mountains cast longer shadows, which slowly cover the brownish tones that colour the magnificent landscape that surrounds Paranal. Soon, the Sun will drop below the horizon, and all the telescopes at Paranal will start another night of observations.

VISTA is a wide-field telescope, designed to map the southern sky in infrared light with high sensitivity, allowing astronomers to detect extremely faint objects. The goal of these surveys is to create large catalogues of celestial objects for statistical studies and to identify new targets that can be studied in more detail by the VLT.

Links

• More about the Visible and Infrared Survey Telescope for Astronomy (VISTA)
• ESO Photo Ambassadors

This impressive panoramic image depicts the Chajnantor Plateau — home of the Atacama Large Millimeter/submillimeter Array (ALMA) — with the majestic Licancabur volcano in the background.  Watched over by Licancabur, a icy forest of penitentes (Spanish for “penitents”) cluster in the foreground. The penitentes are a curious natural phenomenon found in high-altitude regions. They are thin spikes of hardened snow or ice, with sharp edges pointing towards the Sun, reaching heights from a few centimetres up to several metres. You can read more about penitentes in a previous Picture of the Week (potw1221).

The Licancabur volcano, with an altitude of 5920 metres, is the most iconic volcano in the area of San Pedro de Atacama, Chile. Its conical shape makes it easily recognisable even from very far away. It is located on the southernmost part of the border between Chile and Bolivia. The volcano contains one of the world’s highest lakes in its summit crater. This lake has attracted the attention of biologists, who are interested on studying how microscopic organisms can survive in it, despite the very harsh environment of intense ultraviolet radiation, the thin atmosphere, and cold temperatures. The survival strategies of microscopic life in Licancabur Lake may even give us insights into the possibility of life on ancient Mars.

This photograph was taken by Babak Tafreshi, one of the ESO Photo Ambassadors, near the ALMA site.

ALMA, an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

Links

• More about ALMA at ESO
• Joint ALMA Observatory
• ESO Photo Ambassadors