In the context of the Milky Way as a whole, Sgr A* is considered to be the very center of the Galaxy. Sgr A* is one example of a class of objects called Super-Massive Black Holes, or SMBHs.
Clearly the supernova explosion of one star could never produce a single black hole with a mass so large, so this object must have formed in a different manner. The mass that results from the study of this star and other nearby stars is 4 million solar masses! The only type of object that astronomers believe can have a mass of approximately 4 million stars, but a radius of about 100 AU, is a black hole. Using Kepler's laws, if we measure the period and semi-major axis of this star's orbit around Sgr A*, we can calculate the mass of this object. They have measured the orbit of a star that comes within 17 light-hours of the object in the core of our Galaxy, which is a distance that is only a few times larger than the orbit of Pluto around the Sun. Using the highest resolution IR cameras available, astronomers have repeatedly observed the stars orbiting around Sgr A*. See UCLA's Galactic Center Group Animation of the Stars Orbiting Sgr A*. Our solar system is located in one of the spiral arms of the Milky Way galaxy, which is why were so distant from the galactic center. Recently, observations of stars also found to be orbiting Sgr A* have given us significant new insight into the nature of this object. The black hole is about 27,000 light-years away from Earth. It appears to be motionless, but we see gas apparently orbiting the source. This object emits a large amount of radiation in IR, X-rays, and gamma-rays. The team is also working on making a video showing how Sgr A* changes over time.Now let us consider the nature of Sgr A* in particular. Three telescopes were added to the EHT network before the most recent observing campaign in March 2022, which means future pictures should be sharper and should illuminate subtle details in the areas around black holes. It isn’t clear why there is this mismatch in the spin axes of the black hole and the Milky Way, but it could be related to ancient events in which Sgr A* may have devoured black holes at the centres of smaller galaxies.Īs researchers continue to analyse the black hole data and figure out how the two black holes compare to one another, they also have a new set of observations to examine.
Instead of viewing the black hole and its disc from the side, we appear to be viewing it face-on. The only thing that doesn’t line up with what was expected is that the accretion disc around Sgr A* appears to be tilted out of alignment with the disc of the galaxy. “Einstein’s doing well, again, and for people who have all their other theories of what gravity could be it might be a little disappointing.” “One of the things which surprises me personally was just how similar these images are to what theory predicts,” says Younsi. When the researchers compared the image of Sgr A* to a library of hundreds of thousands of simulated black holes modelled in scenarios that do not follow general relativity, they found that Sgr A* appears to hew closely to relativistic models. The gravitational pull of Sgr A* is so strong that it bends the light, making the plasma circling towards us appear brighter than that spinning away towards the black hole’s backside. The most visible prediction of general relativity is that the ring of light around the black hole ought to be a little lopsided. On the other hand, when stars with between 8 and 20 solar masses go supernovae, they. Black holes are objects with an intense gravitational pull so strong that not even beams of light, the fastest things in the universe, can escape. 1 day ago &0183 &32 Stellar-mass black holes are the product of the supernovae of stars with masses 20 times greater than the Sun.