Researchers from the University of Canterbury have revealed the inner goings of nova bursts on white dwarf stars. Their study shows how the star can increase its brightness by thousands of times, making it look like a newly born star. This occurrence is highly representative of our galaxy, happening around ten times a year.
For many years, the scientists believed that the material located on the surface of the white dwarf is responsible for lighting the light of a supernova explosion, being powered by nuclear fusion.
A Stella nova, or merely a nova, is the explosion that happens suddenly on the surface of a white dwarf. The explosion produces an unprecedented amount of light, brightness, and energy, and the star shines even a million times brighter than usual. When the explosion occurs close to our planet, it may look like a newly born star is appearing in the universe.
Scientists explained white dwarf stars’ nova bursts
The new research is stating that the “shock waves” that occur during the explosion of the nova are the ones responsible for the high levels of brightness, contradicting the previous beliefs which state that the nuclear fusion powers the lightning.
The team used for their study the help of a series of NASA’s ground-based telescopes and a couple more from the UC Mt John Observatory. Their study aimed to observe the constellation Carina, which is situated nearby our galaxy, proving that the shock waves are the ones powering nova’s brightness. The results of this study were published earlier this month in the Nature Astronomy journal, and the article is entitled “Direct evidence for shock-powered optical emission in a nova.”
The researchers measured the levels of energy produced by the shock waves of nova bursts, as well as the speed at which they were moving, using the spectroscopy technology. In addition to this, the scientists concluded that each nova explosion is capable of releasing between 10.000 and 100.000 times the annual energy of Earth.