Photo in the News: New Black Hole May Shatter Record
November 1, 2007—It may break the record for breaking a record. A newly discovered black hole is much larger than the previous champion of the same type, which was announced just two weeks ago, scientists say.
According to researchers, the new black hole measures between 24 and 33 times the mass of our sun. By contrast, the M33 X-7 black hole described last month in the journal Nature was estimated to be around 16 solar masses.
Both of the objects belong to a class known as stellar black holes, meaning they formed from the collapses of massive stars.
The new record-setter was found in IC 10, an irregularly shaped galaxy about 1.8 million light-years from Earth. Black holes are so dense not even light can escape their gravitational pull, so scientists were only able to spot the object due to a rare effect: an orbiting star (lower right in above artist's depiction) that periodically blocked x-ray emissions caused by the singularity (upper left).
The find is described in today's issue of the journal Astrophysical Journal Letters but has yet to be confirmed, scientists wrote.
But the puzzling size of the newfound object already has astronomers reconsidering what happens during the death throes of giant stars.
Previous calculations had suggested that the most massive stars in our Milky Way Galaxy could leave behind black holes of no more than 15 to 20 solar masses. Even stars that start off more than five times bigger than that are stripped of most of their material by solar winds and their supernova explosions.
"We now know that black holes that form from dying stars can be much larger than we had realized," study leader Andrea Prestwich of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, said in a press release.
The researchers speculate that stars in IC 10 contain fewer heavy elements, making them less susceptible to solar winds.
