The stripped helium star solves a mystery of massive black hole, Stellar Black holes appear when large stars lose their lives in dramatic destruction. Observations show that stellar black holes usually have a mass about ten times that of the Sun, according to the theory of star evolution.
Recently, a Chinese astronomy team claimed to have discovered a black hole with a mass of 70 solar masses, which, if confirmed, would seriously jeopardize the current view of the star’s evolution. This publication immediately triggered theoretical investigations and additional observations from other astrophysics experts. Among those who watched the site was a team of astronomers, the helium star solves a mystery of massive black hole.
They found that it wasn’t necessarily a black hole, but that it might be a large neutron star or even an “ordinary” star.
The black hole is thought to be found indirectly through the movement of a bright companion star that orbits an invisible compact object for about 80 days. Recent observations show that the Belgian team has shown that initial measurements have been misinterpreted and that the mass of a black hole is actually very uncertain. The most important question, namely how the observed binary system originates, remains open. The determining factor is the visible mass of the satellite, hot star LS V + 22 25.
The larger this star, the greater the black hole to trigger the movement of the brightest star observed. The latter is considered a normal star, eight times bigger than the sun.
The authors conclude that LS V + 22 25 must have interacted with satellites briefly in the past. During this mass transfer episode, the outer layers of the star were removed and the naked helium nucleus, enriched with hydrogen burning ash, is now visible.
However, helium bare stars are much lighter than their normal counterparts. The authors combined their results with recent measurements of the distance to the Space telescope’s Force and most likely determined only 1.1 times (with uncertainty +/- 0.5) the star’s mass is greater than the Sun.
This produces a minimum mass of only 2-3 solar masses for compact satellites, which indicates that it is not necessarily a black hole, but that massive neutron stars or even ordinary stars are possible.
The 25-star LS V + 22 became famous because it might have a large black hole satellite. However, a closer look at the star itself shows that it is a very interesting object, because so far very few naked helium stars with medium mass have been theoretically predicted. They are key objects for understanding binary star interactions.