HD49798 White Dwarf Companion Rotates Every 13 Seconds
Sunday, September 6, 2009 - 10:35
in Astronomy & Space
ESA's XMM-Newton orbiting X-ray telescope has uncovered the first close-up of a white dwarf star, circling a companion star, that could explode into a particular kind of supernova. Well, in a few million years. Astronomers use these supernovae as beacons to measure cosmic distances and could one day help us understand the expansion of the Universe. They've been on the trail of this particular mystery object since 1997 when they discovered that something was giving off X-rays near the bright star HD49798. Now the mysterious object has been tracked along its orbit and observation has shown it to be a white dwarf, the dead heart of a star, shining X-rays into space. read more