Origin of supernova revealed by helium emissions and radio signal

After decades of trying, it fell to astronomers at Stockholm University to uncover the source of a thermonuclear supernova explosion. he was First detection of such a starburst using radio emissionsas well as strong streaks of helium emission from an exploded white dwarf companion.

Features of binary systems in which a star called a white dwarf accumulates material from its companion, Type Ia supernova It is important for astronomers as a reference for measuring the expansion of the universe. Despite this assumption, the exact nature of these actors and how the process works is still unknown to scientists.

Another unprecedented find in this new discovery of supernova SN 2020eyj — strong helium emission lines in the spectrum — He identified the companion as a helium star that must have lost most of its material shortly before the degenerate star of the binary system exploded.

The importance of radio emissions in a supernova

According to the study, published Wednesday (17) in the journal Nature, “one way to distinguish between parent systems is through radio observations.” If the companion star is a conventional star, radio signals must be present. The absence of these in other supernovae is a sign of the merger of two white dwarfs.

According to the first author of the article, Dr. “After seeing the strong interaction signatures with the companion material,” Erik Kool said of the team looking for these emissions. The result was the first time radio detection of a type Ia supernova.

How was supernova SN 2020eyj detected?

Supernova 2020eyj was discovered by the camera of the Zwicky Transient Event Facility (ZTF), an astronomical project based on a large-field research telescope at the Palomar Observatory in the United States.

Other facilities, such as the Scandinavian optical telescope at La Palma and the then-emerging spectra of the large Keck telescope in Hawaii, were necessary to monitor the supernova, according to Professor Jesper Sollerman, co-author of the paper. unusual accumulation of helium around the exploding star.

Meanwhile, Joel Johansson, another author in the Department of Physics, says supernova SN 2020eyj itself is very unusual. Unlike other normal supernovas, “this supernova shows us that: There are many different ways for a white dwarf star to explode.” he concludes.