Artist’s impression of helium-rich materials from a companion star accreting onto a white dwarf. Earlier than the explosion, a considerable amount of materials is stripped from the companion. The analysis group hopes to make clear the connection between the emitted sturdy radio waves and this stripped materials. Credit score: Adam Makarenko/W. M. Keck Observatory
Within the newest challenge of the journal Nature, astronomers from Stockholm College reveal the origin of a thermonuclear supernova explosion. Robust emission traces of helium and the primary detection of such a supernova in radio waves present that the exploding white dwarf star had a helium-rich companion.
Researchers from Stockholm College have found a thermonuclear supernova’s origin traced to a helium-rich companion star of a white dwarf. This primary-ever detection of a supernova in radio waves sheds gentle on the character and processes resulting in Sort Ia supernovae, essential for measuring the universe’s growth. The discovering helps resolve the long-standing query in regards to the course of resulting in the explosion of a white dwarf star and the character of its progenitor, recognized right here as a helium star that had misplaced a lot of its materials simply previous to the white dwarf’s explosion.
Supernovae of Sort Ia are vital for astronomers since they're used to measure the growth of the Universe. Nevertheless, the origin of those explosions has remained an open query. Whereas it's established that the explosion is that of a compact white dwarf star by some means accreting an excessive amount of matter from a companion star, the precise course of and the character of the progenitor are usually not identified. The brand new discovery of supernova SN 2020eyj established that the companion star was a helium star that had misplaced a lot of its materials simply previous to the explosion of the white dwarf.
Artist impression of the double star system with a compact white dwarf star accreting matter from a helium-rich donor companion, surrounded by dense and dusty circumstellar materials. It was the interplay of the exploded star and the fabric left over from this companion that gave rise to the sturdy radio sign and the conspicuous helium traces within the optical spectra of SN 2020eyj. Credit score: Adam Makarenko/W. M. Keck Observatory
“As soon as we noticed the signatures of sturdy interplay with the fabric from the companion we tried to additionally detect it in radio emission,” explains Erik Kool, post-doc on the Division of Astronomy at Stockholm College and lead writer of the paper. “The detection in radio is the primary one in every of a Sort Ia supernova – one thing astronomers have tried to do for many years.”
Supernova 2020eyj was found by the Zwicky Transient Facility digicam on Palomar mountain, the place the Oskar Klein Centre at Stockholm College are members.
“The Nordic Optical telescope on La Palma was elementary for following up this supernova,” says Professor Jesper Sollerman on the Division of Astronomy and co-author of the paper.
“As had been spectra from the big Keck telescope on Hawai’i that instantly revealed the very uncommon helium-dominated materials across the exploded star.”
Erik Kool (heart) and Joel Johansson (left) are post-docs on the Oskar Klein Centre at Stockholm College and lead authors of this paper along with professor Jesper Sollerman (proper) from the Division of Astronomy. Credit score: Magnus Näslund
“That is clearly a really uncommon Sort Ia supernova, however nonetheless associated to those we use to measure the growth of the universe,” provides Joel Johansson from the Division of Physics.
“Whereas regular Sort Ia supernovae seem to all the time explode with the identical brightness, this supernova tells us that there are numerous totally different pathways to a white dwarf star explosion,” he provides.
Reference: “A radio-detected sort Ia supernova with helium-rich circumstellar materials” by Erik C. Kool, Joel Johansson, Jesper Sollerman, Javier Moldón, Takashi J. Moriya, Seppo Mattila, Steve Schulze, Laura Chomiuk, Miguel Pérez-Torres, Chelsea Harris, Peter Lundqvist, Matthew Graham, Sheng Yang, Daniel A. Perley, Nora Linn Strotjohann, Christoffer Fremling, Avishay Gal-Yam, Jeremy Lezmy, Kate Maguire, Conor Omand, Mathew Smith, Igor Andreoni, Eric C. Bellm, Joshua S. Bloom, Kishalay De, Steven L. Groom, Mansi M. Kasliwal, Frank J. Masci, Michael S. Medford, Sungmin Park, Josiah Purdum, Thomas M. Reynolds, Reed Riddle, Estelle Robert, Stuart D. Ryder, Yashvi Sharma and Daniel Stern, 17 Might 2023, Nature.
DOI: 10.1038/s41586-023-05916-w
The paper “A radio-detected Sort Ia supernova with helium-rich circumstellar materials” is revealed in Nature and is led by Erik Kool from the Division of Astronomy at Stockholm College and describes the primary radio detection of a Sort Ia supernova. Co-authors from Stockholm College are Joel Johansson, Jesper Sollerman, Steve Schulze, Peter Lundqvist, Sheng Yang, and Conor Omand. This work concerned researchers from institutes the world over, together with Caltech, Weizmann Institute, IAA-CSIC, NAOJ, Macquarie College, and Trinity Faculty Dublin.
Funding: Vetenskapsrådet (Swedish Analysis Council), Wenner-Gren Basis
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