Successful first observations of galactic center with GRAVITY

Successful first observations of galactic center with GRAVITY
This artist's impression shows stars orbiting the supermassive black hole at the center 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's 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. Calçada

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

GRAVITY is part of the VLT Interferometer. 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 resolving power and positional accuracy—a factor of 15 over the individual 8.2-metre VLT Unit Telescopes—will enable GRAVITY to make amazingly accurate measurements of astronomical objects.

One of GRAVITY's primary goals is to make detailed observations of the surroundings of the 4 million solar mass black hole at the very centre of the Milky Way. Although the position and mass of the black hole have been known since 2002, by making precision measurements of the motions of orbiting it, GRAVITY will allow astronomers to probe the gravitational field around the black hole in unprecedented detail, providing a unique test of Einstein's general theory of relativity.

In this regard, the first observations with GRAVITY are already very exciting. The GRAVITY team 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's sensitivity as it was able to see this faint star in just a few minutes of observation.

The team will soon be able to obtain ultra-precise positions of the orbiting star, equivalent to measuring the position of an object on the Moon with centimetre precision. That will enable them to determine whether the motion around the black hole follows the predictions of Einstein's general relativity—or not. The new observations show that the Galactic Centre is as ideal a laboratory as one can hope for.

"It was a fantastic moment for the whole team when the light from the star interfered for the first time—after eight years of hard work," says GRAVITY's lead scientist Frank Eisenhauer from the Max Planck Institute for Extraterrestrial Physics in Garching, Germany. "First we actively stabilised the interference on a bright nearby star, and then only a few minutes later we could really see the interference from the faint star—to a lot of high-fives." At first glance neither the reference star nor the orbiting star have massive companions that would complicate the observations and analysis. "They are ideal probes," explains Eisenhauer.

This early indication of success does not come a moment too soon. In 2018 the S2 star will be at its closest to the black hole, just 17 light-hours away from it and travelling at almost 30 million kilometres per hour, or 2.5% of the speed of light. At this distance the effects due to general relativity will be most pronounced and GRAVITY observations will yield their most important results. This opportunity will not be repeated for another 16 years.


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First light for future black hole probe

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Citation: Successful first observations of galactic center with GRAVITY (2016, June 23) retrieved 23 July 2019 from https://phys.org/news/2016-06-successful-galactic-center-gravity.html
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Jun 23, 2016
Fiction and reality.
The center of our galaxy has a diameter of 40,000 ly. Supermassive "black hole" has a diameter of less than 1 ly (https://en.wikipe...erties).
The reality is that watching the stars outside the galactic center. The imaginary black hole is located at a distance of 20.000ly of the observed stars.
Hypnosis. Why readers accept such articles as science (and scientific circles) and why not punish of that nonsense.
Statistics: They have seen a black hole in action! ...? http://www.svemir...ack-hole

Jun 23, 2016
@wd.......you betcha, just one more wildass piece of fiction that requires fantasy math. But you can bet that Schneibo will be along shortly with his vaunted Partial Differential Equations proving Infinite Gravity Wells can exist inside of a Finite Stellar mass falsely dubbed Black Holes.

@Schneibo......old boy, still waiting on you to put up solutions to those PDEs you claim exist in between the lines of Einstein's GR whereby you claim to have discovered the proof that Infinite Gravity Wells can exist inside of a Finite Stellar Mass.

Jun 23, 2016
The imaginary black hole is located at a distance of 20.000ly of the observed stars.


No. The bulge has a radius in that ball park but that does not mean every star in the bulge is that far from the center. I'm not sure how you could conclude that. This is the very core of the galactic center. The semi-major axis of say S0-2 is about 980 AU, not 20,000 ly.

The galactic center is only ~25,000 ly away. You're suggested radius would see the orbits being 80 degrees on the sky, while in reality they're observed to be 0.12 arcseconds across.

Jun 23, 2016
@wd.......you betcha, just one more wildass piece of fiction that requires fantasy math. But you can bet that Schneibo will be along shortly with his vaunted Partial Differential Equations proving Infinite Gravity Wells can exist inside of a Finite Stellar mass falsely dubbed Black Holes.

@Schneibo......old boy, still waiting on you to put up solutions to those PDEs you claim exist in between the lines of Einstein's GR whereby you claim to have discovered the proof that Infinite Gravity Wells can exist inside of a Finite Stellar Mass.

And, once again, Benni chimes in with HIS fantasy that people are claiming "Infinite" gravity wells...

Jun 23, 2016
Fantastic! This is currently the highest resolution optical/near infrared instrument in existence. The design has been mooted and some prior such instruments constructed which worked very well (for example the MMT in Arizona), but this one uses movable observatories in the 8-meter class connected by tunnels allowing unprecedented baselines for interferometry giving its extremely high resolution, as well as the ability to adjust the baselines. The beams from two or more of the telescopes are sent down the tunnels and combined into a single image, an extremely exacting technique requiring very fine tuning of all the optical variables to achieve the instrument's capabilities.

We are very lucky to have a nearly ideal observing opportunity coming up in such a short time to make full use of this instrument's observation capabilities. This is not, however, the only thing the instrument can do; it will make unprecedented observations in the decades to come.

Jun 23, 2016
@Schneibo......old boy, still waiting on you to put up solutions to those PDEs you claim exist in between the lines of Einstein's GR
Here you go, Lenni:

-m'' + m'n' - m'² - 2m'/r = 0
m'' + m'² - m'n' - 2m'/r = 0
e⁻²ⁿ (1 + m'r - n'r) - 1 = 0
R₂₂ sin² ϕ = 0

Source: http://www.etsu.e...esis.pdf

That's for the Swartzchild metric (the one that describes a rotationless uncharged black hole).

Be careful what you ask for; you may get it.

Jun 23, 2016
For lurkerz who may be interested:

The prime ' is used in the case above to indicate a derivative; in context, since these are DEs derived from the EFE, these are PDEs, not ODEs. PDEs are used in multidimensional contexts; ODEs in one-dimensional contexts, and the EFE are manifestly multidimensional (they deal with four dimensional spacetime). This is a shorthand notation that can be used for other purposes; context determines the meaning of the prime so don't be surprised if you see it used to indicate the value of a variable after coordinate transformation, or set complements in set theory, or negation of an event in probability theory. For more information see https://en.wikipe...(symbol)

Jun 24, 2016
@Schneibo......old boy, still waiting on you to put up solutions to those PDEs you claim exist in between the lines of Einstein's GR
Here you go, Lenni:
-m'' + m'n' - m'² - 2m'/r = 0
m'' + m'² - m'n' - 2m'/r = 0
e⁻²ⁿ (1 + m'r - n'r) - 1 = 0
R₂₂ sin² Ď� = 0
Source: http://www.etsu.e...esis.pdf
That's for the Swartzchild metric (the one that describes a rotationless uncharged black hole).
Be careful what you ask for; you may get it.


A classic example of faith without any desire to open eyes and awakening from a deep sleep.

Jun 24, 2016
@DaSchneib - thanks for the link -
Sure, man. :D

that's a nice piece of work for a Bachelor's thesis!
I thought so, that guy's got a bright future ahead of him!

I have to agree about this new GRAVITY instrument/capability: there are bound to be a lot of interesting results coming out of the VLTI in the near future. Exciting times, also for new postgrads/docs/postdocs working with the data...
And the JWST going up to supplement it as well. The next couple of decades are going to be pretty interesting, I'd say.

Jun 25, 2016
@Donald Duck
deep sleep

You are confusing General Relativity with Sleeping Beauty.


If this is the a reference to real universe through evidence on unrealistic articles, I would agree with you.

What relativity ignores the fact: the distance of the first stars of the center the Galactic center is minimal 20.000ly. The nearest star is just over 4 ly. Our system is far from the center of the galaxy 29.000ly.

Instead of fiction should be viewed a realistic map of our or any other galaxy and alia.

Jun 25, 2016
What relativity ignores the fact: the distance of the first stars of the center the Galactic center is minimal 20.000ly.

I'm curious. Where the hell did you get THAT bit of info from...?!?

Jun 26, 2016
What relativity ignores the fact: the distance of the first stars of the center the Galactic center is minimal 20.000ly.

I'm curious. Where the hell did you get THAT bit of info from...?!?


The links in the attached article: "They have seen a black hole in action ...?" http://www.svemir...ack-hole

Jun 26, 2016
But the crowning turd in his TOE is his fixation on rotation - in his view, it's not a coincidence that objects in the Universe are rotating, it's due to a deep correlation between them: there's also a deep relation in his mind between rotation of stars and their basic physical properties.

Gravity by any other name (or conjecture), is still - gravity...;-)

My Zadar (bs) radar is definitely on ...

Jun 26, 2016
This comment has been removed by a moderator.

Jun 26, 2016
http://timecube.2enp.com/

A classic of the genre. Has its own pages on RationalWiki and Wikipedia.

I don't know who put it back on line; seems to be some itty bitty hosting company.

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