©ESO/L. Calçada, M. Kornmesser
Researchers have used the Very Large Telescope (VLT) the European Southern Observatory (ESO) observed a new kind of starburst closely. They refer to these as “micronova” – so a smaller nova.
Novae, i.e. outbursts of brightness on white dwarf stars, have generally been known to researchers for centuries and can last for several weeks. The smaller versions are less energy intensive and only last a few hours.
Hydrogen atoms fuse to form helium
In any case, both types of outbursts take place on the surface of white dwarf stars. In micronovae, the massive stars in a binary system can extract material from their companion when they are very close. During this process, hydrogen atoms get onto the hot surface of the white dwarf, causing them to explosively fuse into helium.
With novae, these explosions take place across the entire stellar surface. The research team around Simone Scaringi of the University of Durham has now observed that in micronovae they can also only take place locally at the magnetic poles of the star. What a white dwarf needs for this is a strong magnetic field that transports the extracted material towards the magnetic poles of the star.
Trillions of tons of material burned
According to ESO, a micronova becomes round 20,000 trillion tons material burned. Or in other words: 3.5 billion Great Pyramids of Giza.
The new type of starburst was discovered in data from NASA’s TESS telescope. There was a bright flash that lasted for hours. Using the VLT, it became apparent that the flashes of light originate from white dwarfs. Further investigations should provide more detailed information on this novel phenomenon.
The study was in the journal Nature released.