Astronomers Capture Red Supergiant Star Exploding in Massive Supernova – For the Very First Time

Red Supergiant

An artist’s impression of a red supergiant star in the final year of its life emitting a tumultuous cloud of gas. This suggests at least some of these stars undergo significant internal changes before going supernova. Credit: W.M. Keck Observatory/Adam Makarenko

Astronomers Capture Red Supergiant’s Death Throes

“For the first time, we watched a red supergiant star explode,” researcher says.

For the first time ever, astronomers have imaged in real time the dramatic end to a red supergiant’s life — watching the massive star’s rapid self-destruction and final death throes before collapsing into a type II supernova.

Led by researchers at Northwestern University and the University of California, Berkeley (UC Berkeley), the team observed the red supergiant during its last 130 days leading up to its deadly detonation.

The discovery defies previous ideas of how red supergiant stars evolve right before exploding. Earlier observations showed that red supergiants were relatively quiescent before their deaths — with no evidence of violent eruptions or luminous emissions. The new observations, however, detected bright radiation from a red supergiant in the final year before exploding. This suggests at least some of these stars must undergo significant changes in their internal structure, which then result in the tumultuous ejection of gas moments before they collapse.
“This is a breakthrough in our understanding of what massive stars do moments before they die,” said Wynn Jacobson-Galán, the study’s lead author. “Direct detection of pre-supernova activity in a red supergiant star has never been observed before in an ordinary type II supernova. For the first time, we watched a red supergiant star explode.”

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


An artist’s rendition of a red supergiant star transitioning into a Type II supernova, emitting a violent eruption of radiation and gas on its dying breath before collapsing and exploding. Credit: W. M. Keck Observatory/Adam Makarenko

Although the work was conducted at Northwestern, where Jacobson-Galán was a National Science Foundation (NSF) Graduate Research Fellow, he has since moved to UC Berkeley. Northwestern co-authors include Deanne Coppejans, Charlie Kilpatrick, Giacomo Terreran, Peter Blanchard and Lindsay DeMarchi, who are all members of Northwestern’s Center for Interdisciplinary and Exploratory Research in Astrophysics (CIERA).

‘We’ve never confirmed such violent activity’

The University of Hawaiʻi Institute for AstronomyPan-STARRS on Haleakala, Maui, first detected the doomed massive star in summer 2020 via the huge amount of light radiating from the red supergiant. A few months later, in fall of 2020, a supernova lit the sky.

The team quickly captured the powerful flash and obtained the very first spectrum of the energetic explosion, named supernova 2020tlf (SN 2020tlf) using the W.M. Keck Observatory’s Low Resolution Imaging Spectrometer on Maunakea, Hawaiʻi. The data showed direct evidence of dense circumstellar material surrounding the star at the time of explosion, likely the same gas that Pan-STARRS had imaged the red supergiant star violently ejecting earlier in the summer.

“It’s like watching a ticking time bomb,” said Raffaella Margutti, an adjunct associate professor at CIERA and the paper’s senior author. “We’ve never confirmed such violent activity in a dying red supergiant star where we see it produce such a luminous emission, then collapse and combust, until now.”

The team continued to monitor SN 2020tlf after the explosion. Based on data obtained from Keck Observatory’s Deep Imaging and Multi-Object Spectrograph and Near Infrared Echellette Spectrograph, the researchers determined SN 2020tlf’s progenitor red supergiant star — located in the NGC 5731 galaxy about 120 million light-years away from Earth — was 10 times more massive than the sun.

Remote possibilities

Margutti and Jacobson-Galán conducted most of the study during their time at Northwestern, with Margutti serving as an associate professor of physics and astronomy and member of CIERA, and Jacobson-Galán as a graduate student in Margutti’s research group. Margutti is now an associate professor of astronomy and astrophysics at UC Berkeley.

Northwestern’s remote access to Keck Observatory’s telescopes was integral to their research. From the University’s Evanston campus, astronomers can connect with an on-site telescope operator in Hawaiʻi and choose where to position the telescope. By bypassing long-distance travel to Hawaiʻi, astronomers save precious observing time — often catching transient events like supernovas, which can quickly flare up and then swiftly vanish.

“This significant discovery of a red supergiant supernova is yet one more strong indication of the importance of Northwestern’s investment in access to top private telescope facilities, including the Keck Observatory,” said Vicky Kalogera, the Daniel I. Linzer Distinguished University Professor of Physics and Astronomy at Northwestern’s Weinberg College of Arts and Sciences and director of CIERA. “The Keck telescopes, currently the best on our planet, uniquely enable scientific advances of this caliber as CIERA researchers have shown since our Keck partnership started 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 catch supernovae right after they explode.

“I am most excited by all of the new ‘unknowns’ that have been unlocked by this discovery,” Jacobson-Galán said. “Detecting more events like SN 2020tlf will dramatically impact how we define the final months of stellar evolution, uniting observers and theorists in the quest to solve the mystery on how massive stars spend the final moments of their lives.”

Reference: “Final Moments. I. Precursor Emission, Envelope Inflation, and Enhanced Mass Loss Preceding the Luminous Type II Supernova 2020tlf” by W. V. Jacobson-Galán, L. Dessart, D. O. Jones, R. Margutti, D. L. Coppejans, G. Dimitriadis, R. J. Foley, C. D. Kilpatrick, D. J. Matthews, S. Rest, G. Terreran, P. D. Aleo, K. Auchettl, P. K. Blanchard, D. A. Coulter, K. W. Davis, T. J. L. de Boer, L. DeMarchi, M. R. Drout, N. Earl, A. Gagliano, C. Gall, J. Hjorth, M. E. Huber, A. L. Ibik, D. Milisavljevic, Y.-C. Pan, A. Rest, R. Ridden-Harper, C. Rojas-Bravo, M. R. Siebert, K. W. Smith, K. Taggart, S. Tinyanont, Q. Wang and Y. Zenati, 6 January 2022, The Astrophysical Journal.
DOI: 10.3847/1538-4357/ac3f3a

The study, “Final Moments I: Precursor emission, envelope inflation and enhanced mass loss preceding the luminous type II supernova 2020tlf,” was supported by NASA, the National Science Foundation, the Heising-Simons Foundation, the Canadian Institute for Advanced Research, the Alfred P. Sloan Foundation and VILLUM FONDEN.

13 Comments on "Astronomers Capture Red Supergiant Star Exploding in Massive Supernova – For the Very First Time"

  1. David Cardwell | January 7, 2022 at 4:34 am | Reply

    Has LIGO group coordinated with this observation gravitational waves from the event?

  2. Michael Q. Rudnin | January 7, 2022 at 12:43 pm | Reply

    Youtube’s comments section are as negative as usual.

    • That’s what happens when the uneducated are given a voice

      • Mario Williams | January 8, 2022 at 6:55 am | Reply

        Really???? You only know what you think you know with a finite mind.There are discoveries and rediscoveries that are happening all the time to only contradict your previous theories. In fact thats all they are, they are just theories. Like death, thats not theory that’s fact-only one way you came into the world and a different way out.. Naked you came naked you shall leave. What is your dash. I mean when you expire what does your dash look like are you steady judging or are you trying to know your eternal destiny with your creator GOD., for anything less than “YES LORD” YOU NEED TO REPENT. That’s not judging that’s a fact and it’s righteous judgment. How do I know???? Because you can’t stop anything and miracles do happen (that’s God intervening) and you can’t save yourself from death..you can’t stop one hair from falling it is imminent. So in all your judgment of others instead of judging righteously today your soul maybe required of you. lastly you only know what’s presented to you. You’re not omniscient nor are you omnipotent and because of that fact everything you say and everything you do should and will be taken with a grain of salt. I can get deeper but your theories can’t and won’t stand up to truth, facts and just overall wisdom infact I don’t think you want to and that’s the problem. So stop judging lest you be judged and with the same rule and policy you judge it shall be the rule against you. So be careful of what you say. “The fool has said in his heart there is no GOD. This is just the milk. I’m ready to get the meet of the Word get focused and prepare to give an account for the faith that lies within me

      • Mario Williams | January 8, 2022 at 7:07 am | Reply

        Also be careful what you say about a voice not being heard. Remember what happened to Pharoah. He harden his heart in so much that when he got angry with the GODof Moses Pharoah was so angry that he called for death of all the first born. (God will not be mocked) when he called that action he missed the fact that he had a fist born the heir to the Egyptian throne. And out of Pharaoh’s heart he killed his own son all because of pride.

  3. Wow what an awesome waste of time that video was.

  4. Interesting.

    I wonder what happens to Red Gaints aftr death.

    In terms of Energy- Matter equvalnce! Is there a state of existence between Energy and Matter which we are unable to observe with our senses, and keep calling dark matter?

    To ensure the Balance of the Unverse level between Energy and Matter, i do not see how the Matter-Energy equivalance from the Red Giant becoming imbalanced, unless it has disappeared into another unverse joined at the hip in the Multiverse!

    Views expressed are personal and not binding on anyone.

    • Some of the mass is ejected in the explosion and some of it is also converted into higher elements in the process. The rest likely collapses into a black hole.

  5. If it was observed, how come we can’t see an actual video of it? I was so excited.

  6. Link to scientific reference is invalid so is this even real or made up garbage for sale of clicks… https://doi.org/10.3847/1538-4357/ac3f3a

  7. Janees Naveed | January 8, 2022 at 1:06 pm | Reply

    Amazing… have you heard the voice of explording.. i am also want become a astronomer..

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