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ESO 46/08 - Associated Image and Videos

10 December 2008
For immediate release

Unprecedented 16-Year Long Study Tracks Stars Orbiting Milky Way Black Hole

The central parts of our Galaxy, the Milky Way, as observed in the near-infrared with the NACO instrument on ESO's Very Large Telescope. By following the motions of the most central stars over more than 16 years, astronomers were able to determine the mass of the supermassive black hole that lurks there.
Credit: ESO/S. Gillessen et al.

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Associated Videos - Index

ESO PR Video 46a/08
ESOcast Episode 2: Unprecedented 16-year long study tracks stars orbiting Milky Way black hole

ESO PR Video 46b/08
Video News Release: Unprecedented 16-year long study tracks stars orbiting Milky Way black hole

ESO PR Video 46c/08
B-roll: Reinhard Genzel talks about his research

ESO PR Video 46d/08
B-roll: Stefan Gillessen talks about his research

ESO PR Video 46e/08
B-roll: Artist's impressions and time-lapse sequence with real NACO data

ESO PR Video 46f/08
The Centre of our Galaxy

ESO PR Video 46g/08
The Orbits of the Central Stars

ESO PR Video 46h/08
A Full Orbit of the Star S2

ESO PR Video 46i/08
The Centre of our Galaxy

ESO PR Video 46j/08
Timelapse sequence with VLT and NTT images

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In this second episode of the ESOcast Dr. J takes us to the centre of the Milky Way to talk about a supermassive black hole there located. We will hear from two scientists involved in an unprecedented 16-year long study, which used several of ESO's flagship telescopes to produce the most detailed view ever of the surroundings of the monster lurking at our Galaxy's heart. How were the hidden secrets of this tumultuous region unravelled? Watch this ESOcast and find out.

Credit: Visual design and editing: Martin Kornmesser, Luis Calçada and Herbert Zodet. Host: Dr. J. Footage and photos: ESO/ R.Genzel and S. Gillessen. Web and technical support: Lars Holm Nielsen and Raquel Yumi Shida. Web Hosting: Leibniz-Rechenzentrum (LRZ)

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Images and animations showing the stars orbiting the black hole at the centre of the Galaxy, followed by interviews of Pr Genzel and Dr Gillessen, who reported these results. The roll also includes view from the telescopes used for these observations on ESO's La Silla and Paranal observatories, the NTT and the VLT.
Credit: ESO/ R.Genzel and S. Gillessen

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Reinhard Genzel, from Max-Planck-Institute for Extraterrestrial Physics, was awarded the prestigious Shaw Prize in Astronomy for 2008 for this research. In these statements in English and German, he explains the importance and the context of the results.
Credit: ESO/ R. Genzel

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Stefan Gillessen, from Max-Planck-Institute for Extraterrestrial Physics, lead author of the article presenting the orbits of 28 stars around the Milky Way, explain the results in English and in German.
Credit: ESO/ S. Gillessen

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Sequences showing the real images acquired with the VLT, and 2D and 3D animations illustrating the motion of the stars around the black hole at the centre of the Galaxy.

00:10 - zoom and pan the colour image obtained with the VLT;
00:56- zoom in real images of the galaxies, starting from a wide angle view, all the way to the sequence of real images showing the stars orbiting the black hole at the centre;
01:30- fade from the real data to a 3D animation of the stars around the black hole;
02:00- 3D animation showing the S2 star orbiting the black hole
02:35- 2D animation with all the measured stars, reproducing the real observations.
Credit: ESO/ S. Gillessen, R. Genzel

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In an unprecedented 16-year long study, using several of ESO’s flagship telescopes, astronomers have produced the most detailed view ever of the surroundings of the monster lurking at our Galaxy’s heart – a supermassive black hole. The research has unravelled the hidden secrets of this tumultuous region by mapping the orbits of almost 30 stars.
Credit: ESO/S. Gillessen

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In their unique study stretching over 16 years a team of German astronomers used 28 stars at the heart of the Milky Way’s as “test particles”, watching how they move – much like watching leaves caught in a wintry gust – to reveal the nexus of forces at work there. These observations can then be used to infer some important properties of the central black hole itself, such as its mass and distance. The black hole is found to be a little over four million times the mass of the Sun, and located 27 000 light-years from us. This research marks the first time that so many of these central stars have had their orbits measured precisely and reveals information about the characteristics of these stars and how they must have formed.
Credit: ESO

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For one of the central stars, called S2, the astronomers were able to follow its complete 15 year long orbit! The star approached the black hole to within one light-day – this is only about five times the distance between the planet Neptune and the Sun.
Credit: ESO

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Observers under dark skies, far from the bright city lights, can marvel at the splendour of the Milky Way, arching in an imposing band across the sky. Zooming in towards the centre of our galaxy, about 25 000 light-years away, you can see that it is composed of myriads of stars. This is a pretty impressive sight, but much is hidden from view by interstellar dust, and astronomers need to look using a different wavelength, the infrared, that can penetrate the dust clouds. With large telescopes, astronomers can then see in detail the swarm of stars circling the supermassive black hole, in the same way that the Earth orbits the Sun. This sequence is made of real photos, including the actual high-resolution images of this 16-year long study.
Credit: ESO/S. Gillessen and B. Gilli

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The actual images, that have been collected over the past 16 years, are assembled in this video. The real motion of the stars has been accelerated by a factor 32 millions. The individual images have been shifted and stretched to the same scale and orientation, and cover the central part of the color image presented in the PR photo above.
Credit: ESO/ R.Genzel and S. Gillessen

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