Spanish scientists participate in the discovery of a new cosmic supernova – News

An international team of astronomers, including researchers from the Institute of Space Sciences (ICE-CSIC) and the Institute of Space Research of Catalonia (IEEC), has discovered a hitherto unknown source of dust in the Universe: a type Ia supernova. which interacts with gas in the environment.

The study, published in the journal Nature Astronomy, was led by Lingzhi Wang, a junior researcher at the Chinese Academy of Sciences’ Center for South American Astronomy (CASSACA), in collaboration with astronomers from China, the United States, Chile, the United Kingdom and the United States. Spain (including Luis Galbani and Thomas Müller Bravo, ICE-CSIC and IEEC researchers).

The results are important for science because for a long time the exact nature of dust formation in the Universe remained a mystery, they explain.

The analysis confirms that cosmic dust is actually very similar to dust on Earth: groups of molecules that condensed and were held together in grains.

Supernovae are known to play an important role in dust production, and to date dust production has only been observed during core collapse (or type II) supernovae, which are explosions of massive stars, they say.

This study further indicates that Type Ia thermonuclear supernovae, which are the explosion of a white dwarf star in a binary system with another star, could explain significant amounts of dust in these galaxies.

“This supernova did not initially attract our attention, and a few days into our observing campaign we momentarily lost interest when it temporarily disappeared behind the Sun. However, to our surprise, when it reappeared a few months later, not only was it still detectable. “, but it turned out to be much brighter than expected. It was at that moment that we realized that something truly extraordinary was happening,” says Galbani.

Researchers have been tracking supernova SN 2018evt for more than three years, using space-based facilities such as NASA’s Spitzer Space Telescope and NEOWISE missions, as well as ground-based facilities such as the global network of telescopes at Las Cumbres Observatory and other centers in China. America and Australia.

Scientists from ICE-CSIC and IEEC collaborated to monitor data from the New Technologies Telescope (NTT) in La Silla (Chile) as part of the ePESSTO+ collaboration. They also observed the supernova using the ANDICAM (A Novel Dual Imaging CAMera) camera, which was installed on the 1.3-meter SMARTS telescope on Cerro Tololo (Chile).

The team found that the supernova collided with material previously ejected by one or both stars of the binary system before the white dwarf exploded.

And as the team observed the supernova for more than 1,000 days, they were able to find that its light began to dim sharply in optical wavelengths that our eyes can see, and then began to shine brighter in the infrared, they point out.

“Because gas and dust emit infrared light, observations at these wavelengths are essential for this type of research,” Müller tells Bravo.

“However, despite infrared monitoring of other thermonuclear supernovae, detection of dust formation in these events remained difficult. That’s why we were surprised by this discovery,” he adds.

“The origin of cosmic dust has long remained a mystery. This study marks the first detection of rapid and significant dust formation in a thermonuclear supernova interacting with circumstellar gas,” the researchers summarize.