November 28, 2013
Black Hole Twice As Bright As Astronomers Thought Possible [Study]

A new study has revealed that a black hole system in a galaxy close to ours is twice as bright as astronomers had believed possible.

The system is located about 22 million light-years away from the Earth in the Pinwheel Galaxy, and it might change astronomers' theories about how some black holes radiate energy and light, according to researchers.

Joel Bregman of the University of Michigan, and co-author of the study said in a statement:

"As if black holes weren't extreme enough, this is a really extreme one that is shining as brightly as it possibly can. It's figured out a way to be more luminous than we thought possible."
Astronomers studied a system called ULX-1, which consists of a black hole and a companion star that orbit each other, according to

ULX is short for "ultraluminous X-ray source." The system generates incredible amounts of high-energy X-ray light, which is emitted by material spiraling down into the black hole's jaw.

The new study suggested this black hole is actually on the small side compared to others. The data revealed the light was so intense that astronomers believed ULX-1 contained an intermediate-mass black hole between 100 and 1,000 times the mass of the sun.

Jifeng Liu of the Chinese Academy of Sciences in Beijing led the group of researchers. The team studied ULX-1 using the Gemini Observatory in Hawaii and two NASA spacecraft: the Hubble Space Telescope and the Chandra X-ray Observatory.

The study also found that the black hole's companion star is a big, hot type known as a Wolf-Rayet star.

wolfe rayet star

All these facts helped the team predict the star's mass from its brightness, calculating it at 19 times the mass of the sun.

Researchers also determined both celestial bodies orbit each other once every 8.2 days, and they were also able to estimate that the mass of the black hole is about 20 to 30 times the mass of the sun.

ULX-1 apparently contains a stellar black hole, one that forms after a star dies and collapses in on itself.

"Our findings may turn the trend of taking ultraluminous X-ray sources as promising intermediate black hole candidates," Liu said in a statement.

Researchers aren't sure how the black hole emits so much light.

"Our work shows, based on our conclusion of a stellar mass black hole, that our understanding of the black hole radiation mechanism is incomplete and needs revision," Liu told in an email.