We send you off this Christmas with some astrophysical news, of the whole “stars are totally faking us out” variety. Namely, the fact that a white dwarf was faking the X-ray profile of a “mass-stealing” black hole. To cover up it was actually stealing mass for another star.
In other words… stars can be vampires. Giant thermonuclear vampires.
According to New Scientists, what fooled astronomers at first was the X-rays the white dwarf was giving off. What ultimately sold it up the river was not the burst, but the temperature:
At first glance, the flare matched the behaviour of other ultra-luminous X-ray sources thought to be black holes firing off radiation bursts. But one piece of evidence did not ring true: despite its brightness, the flare’s observed temperature was much lower than that of other black hole outbursts.
They quickly discovered that it was bleeding a larger star of its matter. The white dwarf orbits the smaller start, collecting matter. When enough hydrogen collects, it sets off a massive thermonuclear blast, the source of all those X-rays that were fooling astronomers.
This leads them to believe that there might be fewer black holes than we think, and more of these binary star systems.
So we have a lot more thermonuclear vampires in the universe than we thought. Potentially.