According to some estimates of its mass, the only rogue black hole wandering in the space lanes of our Milky Way galaxy could be the smallest black hole ever found.
Earlier this year, an astronomer led by Kailash Suff of the Space Telescope Science Institute in Baltimore, Maryland announced the discovery of the first known isolated stellar black hole.
Black holes are 5,000 light-years away and are discovered thanks to the force of gravity acting as a gravitational lens, magnifying the light of stars in the background 19,000 light-years away. Initially discovered by two ground surveys, the Polish-led Optical Gravitational Lens Experiment (OGLE), which primarily uses the Las Campanas Observatory in Chile, and the Microlens Observation (MOA) project at the New Mount John University Observatory. Geeland.
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Sahu’s team used the Hubble Space Telescope to track the discovery. Depending on the degree of the gravitational lens, we could conclude that the mass of the black hole is about 7.1 times the mass of the sun.
However, the second team proposed another mass calculation. A group led by Casey Lam at the University of California, Berkeley concluded that the mass of this object is 1.6 to 4.4 times that of the Sun. If correct, this can have interesting implications.
Stellar black holes are the product of supernovae, which have 20 times the mass of the Sun. On the other hand, when a star with a solar mass of 8 to 20 becomes a supernova, a neutron star remains instead.
Neutron stars can theoretically have a mass of up to about 2.3 solar masses. Observations of stellar black holes that can be detected in a star system show nothing when the solar mass is less than 5, and there is a gap between the heaviest neutron star and the least mass black hole. .. If the black hole is at the top of the ram’s mass range, it will help fill this gap. (Several candidate gravitational wave events related to objects falling into this mass gap have also been detected.)
“Whatever it is, the object is the wreckage of the first dark star found wandering the galaxy without another star,” Ram said in a NASA statement. (Opens in a new tab)..
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Stars with a solar mass of more than 20 make up only 0.1% of all stars in the Milky Way, but there are so many stars in the Milky Way (estimated 100-200 billion), and the Milky Way is very old (about 130). 100 million years) Our galaxy should now have more than 100 million stellar mass black holes.
Many of these are found in star systems, and their presence is evident from their gravitational pull on their companions and the accretion of matter from their neighbors. It has also been found inside the Large Magellanic Cloud star cluster NGC1850. However, many others are wandering between the stars and are unnoticed until they find that accidental alignment with the stars in the background creates a gravitational lens.
This discovery is just the tip of the iceberg. NASA’s Nancy Grace Roman Space Telescope, scheduled for launch in 2027, is expected to explore a large area of the Milky Way and identify thousands of microlens events. Many of them can be black holes.
Both papers from Sahu’s team (Opens in a new tab) And Lamb’s team (Opens in a new tab) It is published online.
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