Messier 87, a massive elliptical galaxy located approximately 53 million light-years away in the constellation of Virgo, turns out to be triaxial, or potato-shaped, and hosts a supermassive black hole about 5.4 billion times the mass of the Sun, according to new observations by the NASA/ESA Hubble Space Telescope and the W.M. Keck Observatory.
In most cases, astronomers must use their intuition to figure out the true shapes of deep-space objects.
For example, the whole class of huge galaxies called elliptical galaxies look like blobs in pictures.
Determining the true shape of such galaxies will help astronomers understand better how large galaxies and their central large black holes form.
University of California, Berkeley astronomer Chung-Pei Ma and her colleagues made the 3D plot by measuring the motions of stars that swarm around M87*, the supermassive black hole in the center of Messier 87.
The stellar motion was used to provide new insights into the shape of the galaxy and its rotation, and it also yielded a new measurement of the black hole’s mass.
Tracking the stellar speeds and position allowed the astronomers to build a 3D view of the galaxy.
They were able to determine the mass of M87* to a high precision, estimating it at 5.4 billion times the mass of the Sun.
Hubble observations in 1995 first measured the black hole as being 2.4 billion solar masses, which astronomers deduced by clocking the speed of the gas swirling around the black hole.
When the Event Horizon Telescope (EHT) Collaboration released the first-ever image of the same black hole in 2019, the size of its pitch-black event horizon allowed researchers to calculate a mass of 6.5 billion solar masses using Einstein’s theory of general relativity.
The stereo model of Messier 87 and the more precise mass of the central black hole could help astronomers learn the black hole’s spin rate.
“Now that we know the direction of the net rotation of stars in Messier 87 and have an updated…
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