{"id":12789,"date":"2016-06-23T04:00:08","date_gmt":"2016-06-23T08:00:08","guid":{"rendered":"http:\/\/hobbyspace.com\/Blog\/?p=12789"},"modified":"2016-06-22T12:03:17","modified_gmt":"2016-06-22T16:03:17","slug":"eso-successful-first-observations-of-galactic-centre-with-gravity","status":"publish","type":"post","link":"https:\/\/hobbyspace.com\/Blog\/?p=12789","title":{"rendered":"ESO: Successful First Observations of Galactic Centre with GRAVITY"},"content":{"rendered":"

Here is the latest\u00a0ESO<\/a>\u00a0(European Southern Observatory) report:<\/p>\n

Successful First Observations of Galactic Centre with GRAVITY
\n<\/a><\/strong>Black hole probe now working with the four VLT Unit Telescopes<\/em><\/p>\n

\"eso1622a[1]\"<\/a>
This artist\u2019s impression shows stars orbiting the supermassive black hole at the centre of the Milky Way. In 2018 one of these stars, S2, will pass very close to the black hole and this event will be the best opportunity to study the effects of very strong gravity and test the predictions of Einstein\u2019s general relativity in the near future. The GRAVITY instrument on the ESO Very Large Telescope Interferometer is the most powerful tool for measuring the positions of these stars in existence and it was successfully tested on the S2 star in the summer of 2016. The orbit of S2 is shown in red and the position of the central black hole is marked with a red cross. Credit: ESO\/L. Cal\u00e7ada<\/em><\/figcaption><\/figure>\n

A European team of astronomers have used the new GRAVITY instrument at ESO\u2019s Very Large Telescope to obtain exciting observations of the centre of the Milky Way by combining light from all four of the 8.2-metre Unit Telescopes for the first time. These results provide a taste of the groundbreaking science that GRAVITY will produce as it probes the extremely strong gravitational fields close to the central supermassive black hole and tests Einstein\u2019s general relativity.<\/p>\n

The GRAVITY<\/a> instrument is now operating with the four 8.2-metre Unit Telescopes of ESO\u2019s Very Large Telescope<\/a> (VLT), and even from early test results it is already clear that it will soon be producing world-class science.<\/p>\n

\"eso1622b[1]\"<\/a>
Image of the galactic centre. For the interferometric GRAVITY observations the star IRS 16C was used as a reference star, the actual target was the star S2. The position of the centre, which harbours the (invisible) black hole known as Sgr A*,with 4 million solar masses, is marked by the orange cross. Credit: ESO\/MPE\/S. Gillessen et al.<\/em><\/figcaption><\/figure>GRAVITY is part of the VLT Interferometer<\/a>. By combining light from the four telescopes it can achieve the same spatial resolution and precision in measuring positions as a telescope of up to 130 metres in diameter. The corresponding gains in\u00a0resolving power<\/a> and positional accuracy \u2014 a factor of 15 over the individual 8.2-metre VLT Unit Telescopes \u2014 will enable GRAVITY to make amazingly accurate measurements of astronomical objects.<\/p>\n

One of GRAVITY\u2019s primary goals is to make detailed observations of the surroundings of the 4 million solar mass black hole<\/a>\u00a0at the very centre of the Milky Way [1]<\/a>. Although the position and mass of the black hole have been known since 2002, by making precision measurements of the motions of stars orbiting it, GRAVITY will allow astronomers to probe the\u00a0gravitational field<\/a> around the black hole in unprecedented detail, providing a unique test of Einstein\u2019s general theory of relativity<\/a>.<\/p>\n

https:\/\/cdn.eso.org\/videos\/medium_podcast\/eso1622a.mp4<\/a><\/video><\/div>\n

This artist\u2019s impression shows the orbits of stars around supermassive black hole at the centre of the Milky Way. In 2018 one of these stars, S2, will pass very close to the black hole and present the best opportunity to study the effects of very strong gravity and test the predictions of Einstein\u2019s general relativity in the near future.<\/em><\/p>\n

The GRAVITY instrument on the ESO Very Large Telescope Interferometer is the most powerful tool for measuring the positions of the S2 star in existence and it was successfully tested on the S2 star in summer 2016. The orbit of S2 is highlighted in red and the position of the central black hole is marked with a red cross.\u00a0<\/em>Credit:\u00a0ESO\/L. Cal\u00e7ada<\/em><\/p>\n

In this regard, the first observations with GRAVITY are already very exciting. The GRAVITY team [2]<\/a> has used the instrument to observe a star known as S2 as it orbits the black hole at the centre of our galaxy with a period of only 16 years. These tests have impressively demonstrated GRAVITY\u2019s sensitivity as it was able to see this faint star in just a few minutes of observation.<\/p>\n