 Researchers
from the University of Iowa have discovered a star orbiting a black
hole.University of Iowa researchers have found a giant star
orbiting a medium-sized black hole — a discovery they hope proves
the existence of a new class of black hole and explains how they
evolve.
The discovery was made indirectlyas researchers noticed the black
hole’s X-rays became brighter and dimmer every 62 days. This showed
them how often the star orbited the hole.
“This, in turn, told us that the companion star has to be a giant
star — a phase in the evolution of a star when it becomes extremely
bloated,” said Philip Kaaret, an associate professor in the
university’s physics and astronomy department.
Kaaret said the discovery may help confirm the existence of
“medium-sized” black holes — with masses 100 to 10,000 times more
than the sun. The new class of holes would be larger than black
holes that are formed from a normal star’s collapse and smaller than
the black holes in the centers of galaxies.
The researchers used a special X-ray telescope to find the star
in the nearby starburst galaxy M82. The star is about 1,000 times
larger than the sun. |