In a nearby dwarf galaxy called the Small Magellanic Cloud, astronomers have discovered possibly the most luminous nova ever.
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.
Novae are usually found in visible light, but often go on to emit higher energy X-rays as well. Together, these different datasets provide information on the white dwarf, such as its temperature and chemical composition.
Using NASA’s Swift observatory and ground-based telescopes in South Africa, Australia, and Chile, an international team of astronomers has revealed that a nova dubbed SMCN 2016-10a is the most luminous nova ever discovered in the Small Magellanic Cloud and one of the brightest ever seen in any galaxy.
“Swift’s ability to respond rapidly, together with its daily-planned schedule, makes it ideal for the follow-up of transients, including novae,” said team member Dr. Kim Page, from the University of Leicester.
“It was able to observe SMCN 2016-10a 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.”
“The present observations…