Astronomers discover a small but powerful ‘micronova’ starburst

strong magnetic fields

White dwarf stars found paired with other stars drain hydrogen from their companions like zombies that feed on other stars. When gas collides with the hot surface of the white dwarf’s tubes, the hydrogen atoms fuse with helium and cause an explosion. These events are called supernovae.

“Such eruptions cause the white dwarf’s entire surface to burn and shine bright for several weeks,” Natalie Degenar, an astronomer and assistant professor at the University of Amsterdam, said in a statement.

Micronovae are smaller than typical supernovae and only last a few hours.

Micronova explosions occur on white dwarfs, which have strong magnetic fields that send material toward the star’s poles. This pathway causes hydrogen fusion reactions to occur in more localized regions of the magnetic poles.

“This causes Micronova bombs to explode with a nova blast strength of about one million parts, hence the name Micronova,” study co-author Paul Grote, an astronomer and professor at Radboud University in the US, the Netherlands, said in a statement. . .

Follow the intense but short events

The research team discovered the small flares after looking at data collected by NASA’s Transiting Exoplanet Survey Satellite, or TESS mission. The satellite is used to search for exoplanets, but it also scans nearby stars to look for planets around them.

“When we looked at astronomical data collected by NASA’s TESS, we discovered something unusual: a bright flash of optical light that lasted a few hours. With further research we found several similar signals,” DeGeneres said.

Two of the macronovas fell on white dwarfs, and the third astronomers tracked the Very Large Telescope to make sure it was also a white dwarf. This allowed the researchers to announce their observations about the discovery of something new.

Now that micronovae have become their own class of starbursts, the research team hopes to monitor more of them to see how common they are — especially as this challenges current understanding of starbursts.

“It just shows how dynamic the universe is,” Scaringi said. “These events may actually be very common, but because they are so fast, it’s hard to catch them in action.”