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18 February 2009: A team of French astronomers has captured one of the sharpest colour images ever made. They observed the star T Leporis, which appears, on the sky, as small as a two-storey house on the Moon [1]. The image was taken with ESO's Very Large Telescope Interferometer (VLTI), emulating a virtual telescope about 100 metres across and reveals a spherical molecular shell around an aged star.

4 February 2009: A team of French and Italian astronomers have devised a new method for measuring the size and shape of asteroids that are too small or too far away for traditional techniques, increasing the number of asteroids that can be measured by a factor of several hundred. This method takes advantage of the unique capabilities of ESO's Very Large Telescope Interferometer (VLTI).

10 October 2008: Astronomers have used ESO's Very Large Telescope Interferometer to conduct the first high resolution survey that combines spectroscopy and interferometry on intermediate-mass infant stars. They obtained a very precise view of the processes acting in the discs that feed stars as they form. These mechanisms include material infalling onto the star as well as gas being ejected, probably as a wind from the disc.

18 September 2008: The PRIMA instrument [1] of the ESO Very Large Telescope Interferometer (VLTI) recently saw "first light" at its new home atop Cerro Paranal in Chile. When fully operational, PRIMA will boost the capabilities of the VLTI to see sources much fainter than any previous interferometers, and enable astrometric precision unmatched by any other existing astronomical facility. PRIMA will be a unique tool for the detection of exoplanets.

24 July 2008: Using ESO's Very Large Telescope Interferometer, and its remarkable acuity, astronomers were able for the first time to witness the appearance of a shell of dusty gas around a star that had just erupted, and follow its evolution for more than 100 days. This provides the astronomers with a new way to estimate the distance of this object and obtain invaluable information on the operating mode of stellar vampires, dense stars that suck material from a companion.

27 May 2008: Talk about a diet! By resolving, for the first time, features of an individual star in a neighbouring galaxy, ESO's VLT has allowed astronomers to determine that it weighs almost half of what was previously thought, thereby solving the mystery of its existence. The behemoth star is found to be surrounded by a massive and thick torus of gas and dust, and is most likely experiencing unstable, violent mass loss.

29 January 2008: Using ESO's Very Large Telescope Interferometer, astronomers have probed the inner parts of the disc of material surrounding a young stellar object, witnessing how it gains its mass before becoming an adult.

27 September 2007: A team of European astronomers has used ESO's Very Large Telescope Interferometer and its razor-sharp eyes to discover a reservoir of dust trapped in a disc that surrounds an elderly star. The discovery provides additional clues about the shaping of planetary nebulae.

27 September 2007: Using ESO's Very Large Telescope Interferometer and its unique ability to see small details, astronomers have uncovered a flat, nearly edge-on disc of silicates in the heart of the magnificent Ant Nebula. The disc seems, however, too 'skinny' to explain how the nebula got its intriguing ant-like shape.

3 August 2007: Using ESO's Very Large Telescope Interferometer, astronomers from France and Brazil have detected a huge cloud of dust around a star. This observation is further evidence for the theory that such stellar puffs are the cause of the repeated extreme dimming of the star.

31 May 2007: Using ESO's VLTI on Cerro Paranal and the VLBA facility operated by NRAO, an international team of astronomers has made what is arguably the most detailed study of the environment of a pulsating red giant star. They performed, for the first time, a series of coordinated observations of three separate layers within the star's tenuous outer envelope: the molecular shell, the dust shell, and the maser shell, leading to significant progress in our understanding of the mechanism of how, before dying, evolved stars lose mass and return it to the interstellar medium.

23 February 2007: The ESO Very Large Telescope Interferometer, which allows astronomers to scrutinise objects with a precision equivalent to that of a 130-m telescope, is proving itself an unequalled success every day. One of the latest instruments installed, AMBER, has led to a flurry of scientific results, an anthology of which is being published this week as special features in the research journal Astronomy & Astrophysics.

20 September 2006: Thanks to the unique possibilities offered by ESO's Very Large Telescope Interferometer (VLTI), astronomers have solved a 140-year-old mystery concerning active hot stars. They indeed show that the star Alpha Arae is spinning almost on the verge of breaking and that its disc rotates the same way planets do around the Sun.

28 February 2006: Using ESO's Very Large Telescope Interferometer (VLTI) at Cerro Paranal, Chile, and the CHARA Interferometer at Mount Wilson, California, a team of French and North American astronomers has discovered envelopes around three Cepheids, including the Pole star. This is the first time that matter is found surrounding members of this important class of rare and very luminous stars whose luminosity varies in a very regular way. Cepheids play a crucial role in cosmology, being one of the first "steps" on the cosmic distance ladder.

24 November 2005: Using the newly installed AMBER instrument on ESO's Very Large Telescope Interferometer, which combines the light from two or three 8.2-m Unit Telescopes thereby amounting to observe with a telescope of 40 to 90 metres in diameter, two international teams of astronomers observed with unprecedented detail the environment of two stars. One is a young, still-forming star and the new results provide useful information on the conditions leading to the creation of planets. The other is on the contrary a star entering the latest stages of its life. The astronomers found, in both cases, evidence for a surrounding disc.

24 November 2004: One of the currently hottest astrophysical topics - the hunt for Earth-like planets around other stars - has just received an important impetus from new spectral observations with the MIDI instrument at the ESO VLT Interferometer (VLTI). An international team of astronomers [2] has obtained unique infrared spectra of the dust in the innermost regions of the proto-planetary discs around three young stars - now in a state possibly very similar to that of our solar system in the making, some 4,500 million years ago. Reporting in this week's issue of the science journal Nature, and thanks to the unequalled, sharp and penetrating view of interferometry, they show that in all three, the right ingredients are present in the right place to start formation of rocky planets at these stars.

5 May 2004: Fulfilling an old dream of astronomers, observations with the Very Large Telescope Interferometer (VLTI) at the ESO Paranal Observatory (Chile) have now made it possible to obtain a clear picture of the immediate surroundings of the black hole at the centre of an active galaxy. The new results concern the spiral galaxy NGC 1068, located at a distance of about 50 million light-years. They show a configuration of comparatively warm dust (about 50°C) measuring 11 light-years across and 7 light-years thick, with an inner, hotter zone (500°C), about 2 light-years wide. These imaging and spectral observations confirm the current theory that black holes at the centres of active galaxies are enshrouded in a thick doughnut-shaped structure of gas and dust called a "torus." For this trailblazing study, the first of its kind of an extragalactic object by means of long-baseline infrared interferometry, an international team of astronomers [2] used the new MIDI instrument in the VLTI Laboratory. It was designed and constructed in a collaboration between German, Dutch and French research institutes [3]. Combining the light from two 8.2-m VLT Unit Telescopes during two observing runs in June and November 2003, respectively, a maximum resolution of 0.013 arcsec was achieved, corresponding to about 3 light-years at the distance of NGC 1068. Infrared spectra of the central region of this galaxy were obtained that indicate that the heated dust is probably of alumino-silicate composition. The new results are published in a research paper appearing in the May 6, 2004, issue of the international research journal Nature.

18 November 2003: Ever since 1841, when the until then inconspicuous southern star Eta Carinae underwent a spectacular outburst, astronomers have wondered what exactly is going on in this unstable giant star. However, due to its considerable distance - 7,500 light-years - details of the star itself were beyond observation. This star is known to be surrounded by the Homunculus Nebula , two mushroom-shaped clouds ejected by the star, each of which is hundreds of times larger than our solar system. Now, for the first time, infrared interferometry with the VINCI instrument on ESO's Very Large Telescope Interferometer (VLTI) enabled an international team of astronomers [1] to zoom-in on the inner part of its stellar wind. For Roy van Boekel , leader of the team, these results indicate that " the wind of Eta Carinae turns out to be extremely elongated and the star itself is highly unstable because of its fast rotation."

19 June 2003: Active galactic nuclei (AGN) are one of the most energetic and mysterious phenomena in the universe. In some galaxies indeed, the core generates amounts of energy which surpass those of normal galaxies, such as the Milky Way, by many orders of magnitude. The central engine of these power stations is thought to be a supermassive black hole. Indirect lines of evidence have suggested that these massive black holes are enshrouded in a thick doughnut-shaped structure of gas and dust, which astronomers call a "torus". However, due to the limited sharpness of images that can be obtained with present telescopes in the 10-m range, such a torus has never been imaged to date. Using the new and powerful VLT Interferometer [1] - a mode of the ESO Very Large Telescope that combines light from at least two telescopes to obtain information on very fine scales - a team of European astronomers [2] has succeeded for the first time in resolving structures in the dusty torus of the prototype AGN, the famous galaxy NGC 1068. The structures have a size of roughly 0.03 arcsec, corresponding to about 10 light-years at the distance of the galaxy. This important achievement shows that the VLT Interferometer, using the recently inaugurated MIDI instrument [3], proves an invaluable tool in the study of objects outside our own Galaxy.

11 June 2003: To a first approximation, planets and stars are round. Think of the Earth we live on. Think of the Sun, the nearest star, and how it looks in the sky. But if you think more about it, you realize that this is not completely true. Due to its daily rotation, the solid Earth is slightly flattened ("oblate") - its equatorial radius is some 21 km (0.3%) larger than the polar one. Stars are enormous gaseous spheres and some of them are known to rotate quite fast, much faster than the Earth. This would obviously cause such stars to become flattened. But how flat? Recent observations with the VLT Interferometer (VLTI) at the ESO Paranal Observatory have allowed a group of astronomers [1] to obtain by far the most detailed view of the general shape of a fast-spinning hot star, Achernar (Alpha Eridani) , the brightest in the southern constellation Eridanus (The River). They find that Achernar is much flatter than expected - its equatorial radius is more than 50% larger than the polar one! In other words, this star is shaped very much like the well-known spinning-top toy, so popular among young children. The high degree of flattening measured for Achernar - a first in observational astrophysics - now poses an unprecedented challenge for theoretical astrophysics . The effect cannot be reproduced by common models of stellar interiors unless certain phenomena are incorporated, e.g. meridional circulation on the surface ("north-south streams") and non-uniform rotation at different depths inside the star. As this example shows, interferometric techniques will ultimately provide very detailed information about the shapes, surface conditions and interior structure of stars.