Scientists discover one of the most luminous new stars ever
Astronomers have today announced that they have discovered possibly the most luminous ‘new star’ ever – a nova discovered in the direction of one of our closest neighboring galaxies: The Small Magellanic Cloud.
Astronomers from the University of Leicester contributed to the discovery by using the Swift satellite observatory to help understand what was likely the most luminous white dwarf eruption ever seen.
A nova happens when an old star erupts dramatically back to life. In a close binary star system consisting of a white dwarf and a Sun-like companion star, material is transferred from the companion to the white dwarf, gradually building up until it reaches a critical pressure. Then uncontrolled nuclear burning occurs, leading to a sudden and huge increase in brightness. It is called a nova because it appeared to be a new star to the ancients.
Using telescopes from South Africa to Australia to South America, as well as the orbiting Swift observatory, a team led by the South African Astronomical Observatory has revealed that the nova SMCN 2016-10a, which was discovered on 14th October 2016, is the most luminous nova ever discovered in the SMC, and one of the brightest ever seen in any galaxy. The observations that they made are the most comprehensive ever for a nova in this galaxy.
Dr Kim Page, a member of the Swift team at the University of Leicester, led the X-ray analysis, while Paul Kuin, from the Mullard Space Science Laboratory, University College London, organised the UV data.
Dr Page said: "Swift's ability to respond rapidly, together with its daily-planned schedule, makes it ideal for the follow-up of transients, including novae. It was able to observe the nova throughout its eruption, starting to collect very useful X-ray and UV data within a day of the outburst first being reported. The X-ray data were essential in showing that the mass of the white dwarf is close to the theoretical maximum; continued accretion might cause it eventually to be totally destroyed in a supernova explosion."