This black hole isn’t like one you’d normally see in space

BLACK holes are complicated enough to understand at the best of times, but this recently discovered one has everyone puzzled.

What’s wrong with this black hole?

AN astrophysicist has discovered something even rarer than a double-black hole galaxy — a skinny black hole.

The University of Colorado’s Julie Comerford reported her findings on Tuesday at the American Astronomical Society’s annual meeting in Kissimmee, Florida.

To date, only 12 galaxies are known to exist with two black holes in their midst, Comerford said. Normally galaxies have a single supermassive black hole at the centre, equivalent to one million to one billion times the mass of our sun.

But in this newly identified galaxy about one billion light-years away, one of the two black holes is significantly smaller than the other and apparently starved of stars. Black holes typically are surrounded by stars, but this one appears “naked”.

“The southern black hole has 500 times fewer stars associated with it than the northern black hole,” Comerford said. “We are trying to find out why there is such a discrepancy.”

Comerford speculated the slim black hole lost mass in the collision of two galaxies that merged into this one — “One possibility is that its stars were ripped away by gravitational forces ... In other words: it went on a major crash diet.”

This image provided by CU-Boulder shows the galaxy SDSS J1126+2944 taken with the Hubble Space Telescope and the Chandra X-ray Observatory, with an arrow placed by the source pointing to a black hole that lost most of its stars. The University of Colorado's Julie Comerford has discovered something even rarer than a double-black hole galaxy: a skinny black hole. Her findings were reported Tuesday, Jan 5, 2016 at the American Astronomical Society's annual meeting. (NASA/CU-Boulder via AP)

Or it’s a rare example of an intermediate-sized black hole that likely will morph over time into a supermassive monster.

Astronomers have yet to confirm an intermediate-size black hole, which makes Comerford’s streamlined target extra tantalising.

Comerford used the Hubble Space Telescope and NASA’s Chandra X-ray Observatory in her study. She discovered this latest two-black hole galaxy — her fourth — last year. Finding a potential intermediate-size black hole inside was “an extra bonus”, she told reporters.

The first double-black hole galaxy was found in 2003 by accident, according to Comerford. She is trying to systematically uncover more. The findings should shed light on the evolution of black holes.