New images zoom right into the black hole at the centre of our Galaxy

By James Cutmore

Published: Tuesday, 14 December 2021 at 12:00 am

The European Southern Observatory’s Very Large Telescope Interferometer (ESO’s VLTI) has obtained the deepest and sharpest images to date of the region around the supermassive black hole at the centre of our Galaxy.

The new images, obtained between March and July 2021, zoom in 20 times more than what was possible before the VLTI and have helped astronomers find a never-before-seen star close to the black hole. By tracking the orbits of stars at the centre of our Milky Way, the ESO team have been able to make the most precise measurement yet of the black hole’s mass.

“We want to learn more about the black hole at the centre of the Milky Way, Sagittarius A*: How massive is it exactly? Does it rotate? Do stars around it behave exactly as we expect from Einstein’s General Theory of Relativity? The best way to answer these questions is to follow stars on orbits close to the supermassive black hole. And here we demonstrate that we can do that to a higher precision than ever before,” explains Reinhard Genzel, a director at the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching, Germany.

ESO’s upcoming Extremely Large Telescope (ELT), under construction in the Chilean Atacama Desert, will further allow the team to measure the velocity of these stars with very high precision.

Stars orbiting our closest supermassive black hole

"stars
These annotated images, obtained with the GRAVITY instrument on ESO’s Very Large Telescope Interferometer (VLTI) between March and July 2021, show stars orbiting very close to Sgr A*, the supermassive black hole at the heart of the Milky Way. One of these stars, named S29, was observed as it was making its closest approach to the black hole at 13 billion kilometres, just 90 times the distance between the Sun and Earth. Another star, named S300, was detected for the first time in the new VLTI observations. To obtain the new images, the astronomers used a machine-learning technique, called Information Field Theory. They made a model of how the real sources may look, simulated how GRAVITY would see them, and compared this simulation with GRAVITY observations. This allowed them to find and track stars around Sagittarius A* with unparalleled depth and accuracy. Photo by ESO/GRAVITY collaboration

The star orbit images in detail

"stars
Photo by ESO/GRAVITY collaboration
"stars
Photo by ESO/GRAVITY collaboration
"stars
Photo by ESO/GRAVITY collaboration
"This
These images show stars orbiting very close to Sgr A* (centre, not visible), the supermassive black hole at the heart of the Milky Way. They were obtained with the GRAVITY instrument on ESO’s Very Large Telescope Interferometer (VLTI) at the end of July 2021. Photo by ESO/GRAVITY collaboration

Take a look at our other great images galleries:

The constellation of Sagittarius

"Wide-field
This visible light wide-field view shows the rich star clouds in the constellation of Sagittarius (the Archer) in the direction of the centre of our Milky Way galaxy. The entire image is filled with vast numbers of stars, but far more remain hidden behind clouds of dust and are only revealed in infrared images. This view was created from photographs in red and blue light and forming part of the Digitized Sky Survey 2. Photo by ESO/Digitized Sky Survey 2/Davide De Martin/S Guisard

 

This zoom video sequence starts with a broad view of the Milky Way. We then dive into the dusty central region to take a much closer look. There, a swarm of stars orbit around an invisible object: a supermassive black hole, 4.3 million times the mass of the Sun. As we get closer to it, we see these stars, as observed by the NACO instrument on ESO’s Very Large Telescope (the last observation being from 2019). As we zoom in further, we see stars even closer to the black hole, observed with the GRAVITY instrument on ESO’s Very Large Telescope Interferometry in mid-2021. Video by ESO/GRAVITY/L Calçada/N Risinger/DSS. Music by Johan Monel

 

 

Tagged