Science & Technology

Astronomers capture a red supergiant exploding in a large supernova – for the first time

Impressions of a red supergiant artist emitting a turbulent cloud of gas in the last years of life. This suggests that at least some of these stars undergo significant internal changes before going to supernovae.Credits: WM Keck Observatory / Adam Makarenko

Astronomers capture the death throw of a red supergiant

“For the first time, I saw a red supergiant explode,” says the researchers.

For the first time, astronomers imagined the dramatic end of the life of a red supergiant in real time. We are observing the tragedy of rapid self-destruction and final death of a giant star before it collapses into a Type II supernova.

Led by researchers Northwestern University And that University of California, Berkeley (University of California, Berkeley), the team observed a red supergiant during the last 130 days leading up to the deadly explosion.

This finding goes against previous ideas of how red supergiants evolve just before they explode. Previous observations have shown that red supergiants were relatively stationary before their death. There was no evidence of a violent eruption or luminescence. However, new observations have detected bright radiation from red supergiants in the final year before the explosion. This suggests that at least some of these stars must undergo significant changes in their internal structure, which results in a noisy release of gas moments before they collapse.
“This is a breakthrough in our understanding of what a giant star will do just before it dies,” said Win Jacobson Galan, lead author of the study. “Direct detection of pre-supernova activity in red supergiants has never been observed in normal type II supernovae. For the first time, we saw a red supergiant explode.”

The discovery was published today on January 6, 2022. Astrophysical Journal..

An artist’s expression that a red supergiant emits a violent eruption of radiation and gas into its dying breath before it transitions to a type II supernova and collapses and explodes.Credits: WM Keck Observatory / Adam Makarenko

The work took place at Northwestern University, where Jacobson Galan was a graduate researcher at the National Science Foundation Network (NSF) before moving to the University of California, Berkeley. Northwest co-authors include Deanne Coppejans, Charlie Kilpatrick, Giacomo Terreran, Peter Blanchard and Lindsay De Marchi. All of these are members of the Interdisciplinary Exploratory Research Center for Astrophysics (CIERA) in Northwestern.

“We have never seen such violent activity.”

Pan-STARRS, the Institute for Astronomy, University of Hawaii, located in Haleakala, Maui, first detected the fateful giant star in the summer of 2020 through the massive amount of light emitted by the red supergiant. A few months later, in the fall of 2020, a supernova illuminated the sky.

The team immediately captured a powerful flash and used the low-resolution imaging spectrometer at the WM Keck Observatory in Mauna Kea, Hawaii to capture the first spectrum of an energy explosion named Supernova 2020tlf (SN 2020tlf). The data provide direct evidence of the high density of peri-star material surrounding the star during an explosion. This could be the same gas that the PanSTARRS imagined a red supergiant emitting violently in early summer.

“It’s like watching a time bomb,” said Raffaella Margutti, a part-time associate professor at CIERA and the lead author of the paper. “I’ve never seen such a violent activity when I saw a red supergiant emitting such a luminescence, collapsing and burning.”

The team continued to monitor the SN2020tlf after the explosion. Based on data from the Keck Observatory’s deep imaging and multi-object spectrographs and near-infrared echelet spectrographs, researchers found a precursor to the SN2020tlf in the NGC5731 galaxy, about 120 million light-years from Earth. We have determined that there are 10 times more red supergiants. Greater than the sun.

Remote potential

Margutti and Jacobson-Galán conducted most of the research at Northwestern University. Margutti is an associate professor of physics and astronomy, a member of CIERA, and Jacobson-Galán is a graduate student in Margutti’s research group. Margutti is currently an associate professor of astronomy and astrophysics at the University of California, Berkeley.

Remote access to the Keck Observatory telescope at Northwestern University was essential to their research. From the university’s Evanston campus, astronomers can connect with Hawaii’s onsite telescope operators and choose where to place their telescopes. By bypassing long-distance trips to Hawaii, astronomers can save valuable observation time. Often catches temporary events like supernovae.

“This important discovery of the red supernova further underscores the importance of Northwestern University’s investment in access to prestigious private telescope facilities, including the Keck Observatory,” said Vicky, Professor of Physics, Daniel I. Linzer. Carogera says. Director of Astronomy and CIERA at Weinberg University of Arts and Sciences, Northwestern University. “Currently the best Keck telescopes on the planet, as CIERA researchers have shown, uniquely enable scientific progress in this aperture since the Keck partnership began just a few years ago.”

Margutti, Jacobson-Galán, and their northwestern co-authors are members of the Young Supernova Experiment, which uses the Pan-STARRS telescope to capture supernovae shortly after the explosion.

“I’m most excited about all the new’unknowns’ unleashed by this discovery,” said Jacobson Galan. “Detecting more events like SN2020tlf has a dramatic impact on how we define the last moon of stellar evolution, the mystery of how giant stars spend the last moments of life. Connect the observer and the theorist to solve. “

Reference: “Final Moment. I.WV Jacobson-Galán, L. Dessart, DO Jones, R. Margutti, DL Coppejans, G. Dimitriadis, RJ Foley, CD Kilpatrick, DJ Matthews, S. Rest, G. Terreran, PD Aleo, K. Auchettl, PK Blanchard, DA Coulter, KW Davis, TJL de Boer, L. DeMarchi, MR Drout, N. Earl, A. Gagliano, C. Gall, J. Hjorth, ME Huber, AL Ibik, D. Milisavljevic, Y.-C. Pan, A. Rest, R. Ridden-Harper, C. Rojas-Bravo, MR Siebert, KW Smith, K. Taggart, S. Tinyanont, Q. Wang, Y. Zenati, 2022 1 6th of March Astrophysical Journal..
DOI: 10.3847 / 1538-4357 / ac3f3a

The study of “Final Moment I: Precursor Emission, Envelope Inflation, and Enhanced Mass Loss Prior to Type II Supernova 2020tlf” NASA, National Science Foundation, Heidi Simons Foundation, Canadian Institute for Advanced Research, Alfred P. Sloan Foundation, VILLUMFONDEN.

Astronomers capture a red supergiant exploding in a large supernova – for the first time Astronomers capture a red supergiant exploding in a large supernova – for the first time

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