First Observational Proof of Existence of a Double-Degenerate, Super-Chandrasekhar System
An international group of astronomers has found the first pair of white dwarfs with a total combined mass unequivocally above the Chandrasekhar limit of 1.4 solar masses. The orbital period of the system is 4.2 hours, which means that the stars are close enough to spiral in due to the emission of gravitational waves and eventually merge in about 700 million years. This finding, which has been published in Nature, provides observational support to the double-degenerate path of formation of type Ia supernovae, so far a theoretical possibility under ongoing debate. Read more
At the centre of a mysterious nebula, astronomers have discovered two stars locked in such a tight orbit that they will eventually merge and explode. Both stars are white dwarfs - the heaviest such pair ever discovered. Read more
First pair of merging stars destined to become supernova found
Astronomers using ESO facilities in combination with telescopes in the Canary Islands have identified two surprisingly massive stars at the heart of the planetary nebula Henize 2-428. As they orbit each other the two stars are expected to slowly get closer and closer, and when they merge, about 700 million years from now, they will contain enough material to ignite a vast supernova explosion. The results will appear online in the journal Nature on 9 February 2015. Read more