If you think you’re having a bad day, spare a thought for the surviving star in a binary system after its stellar neighbor detonates as a powerful supernova.
Now, NASA’s Chandra X-ray Observatory and a number of ground-based telescopes have taken a close look into a supernova remnant and spied a battered star that was once part of a binary pair and, amazingly, appears to be in one piece.
The supernova remnant DEM L241 is a glowing cloud of gas and dust in the Large Magellanic Cloud, a dwarf galaxy 199,000 light-years away. Supernova remnants are expected to remain very hot for thousands of years after the supernova has occurred, making it a perfect target for Chandra to observe the nebula’s X-ray afterglow.
Once part of a binary system, one of the massive stars ran out of hydrogen fuel at the end of its life and exploded. Astrophysicists suspect that either a neutron star (the hyperdense spinning husk of a star’s core) or a black hole remains behind. If confirmed, this will be only the third ever massive star-black hole/neutron star binary system discovered after a supernova.
Through analysis of Chandra X-ray data, astronomers have found that the remnant is rich in oxygen, neon and magnesium, which suggests the pre-supernova star had a mass of between 25-40 times the mass of our sun.
Ground based observatories are now on the case, tracking orbital velocity variations of the battered remaining star in the system. It has an orbital period of only 10 days and by careful measurements of the orbital speed variations, astronomers will hopefully determine what the star is orbiting — a neutron star or black hole.
In the far future, the remaining star is expected to also explode as a supernova, potentially creating a double neutron star system, a neutron star-black hole system or even a double black hole system.