There must be millions of “wandering black holes” orbiting the Milky Way alone, and they are small and very quiet in mass, so it is difficult for astronomers to find direct evidence for the existence of wandering black holes. After six years of observation, two independent teams are now using a Hubble telescope to estimate the mass of a black hole 5,000 light-years away from Earth, although this is the first time the results of both parties have been slightly different. Direct evidence of a rotating black hole has been provided.

In early February this year, scientists combined 27 years of observational data from the Hubble Space Telescope and ground-based telescopes to discover a 270-day microlensing event, which they suspect is a stray black hole with a mass 7.1 times that of the Sun. Stellar binary system.At a speed of about 45 kilometers per second, it moves faster than the stars around the region, but at that time the newspaper had not yet reviewed it.

Two teams led by Kailash Sahu of the Space Telescope Science Institute and Casey Lam of the University of California, Berkeley have now published separate papers on the analysis of OB110462.Astrophysical Journal(Astrophysical Journal)Astrophysical Journal Newsletter(Astrophysical Journal Letters) ”to discover the details of this vast universe; Because both teams observed the same object, the black holes were named OGLE-2011-BLG-0462 and MOA-2011-BLG-191, respectively. OB110462, abbreviated 5,150 light-years from Earth, is located on the Centaurus arm below the ship’s Milky Way.

Many terrestrial telescopes observe the brightness changes of millions of stars in the center of the Milky Way, due to the effect of gravitational lensing as a giant object passes between the Earth and the stars.

OB110462 was discovered by a microlensing event. Scientists believe that OB110462 was previously an O-type star 90 times the mass of the Sun. However, the results of the calculation of the mass of the black hole are slightly different, with Kailash Sahu’s team believing that OB110462 is 7 times the mass of the Sun, and Casey Lam’s team believes that this is 1.6 to 4.4 times the mass of the Sun. Researchers want to say that this is indeed a black hole, which may actually be a neutron star.

However, microlensing events are now the only technology that can detect stray black holes. This may be the first black hole we have strayed into the Milky Way. Located 80 light years away.

(Source of the first image:NASA)

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