May 3, 2024

Extreme Weight Loss: Shocking Supernova Discovery Challenges the Standard Theory of Stellar Evolution

In the year prior to going supernova the red supergiant star now known as SN 2023ixf shed an unexpected amount of mass equivalent to the mass of the Sun. This artists conception highlights what the lasts of mass loss might have looked like before the star took off. Credit: Melissa Weiss/CfA
Proof of extreme pre-explosion mass loss in a recently found supernova indicates there may be more going on in the last year of a stars life than formerly believed.
A recently found neighboring supernova whose star ejected up to a full solar mass of material in the year prior to its explosion is challenging the basic theory of excellent development. The new observations are giving astronomers insight into what takes place in the last year prior to a stars death and surge.
Core-Collapse Supernovae and SN 2023ixf
SN 2023ixf is a brand-new Type II supernova discovered in May 2023 by amateur astronomer Kōichi Itagaki of Yamagata, Japan shortly after its progenitor, or origin star, exploded. Located about 20 million light-years away in the Pinwheel Galaxy, SN 2023ixfs proximity to Earth, the supernovas extreme brightness, and its young age make it a gold mine of observable data for researchers studying the death of massive stars in supernova explosions.

Type II or core-collapse supernovae happen when red supergiant stars a minimum of eight times, and as much as about 25 times the mass of the Sun, collapse under their own weight and explode. While SN 2023ixf fit the Type II description, follow-up multi-wavelength observations led by astronomers at the Center for Astrophysics|Harvard & & Smithsonian (CfA), and utilizing a broad variety of CfAs telescopes, have actually exposed unexpected and new behavior.
Among the closest Type II supernovae in a years and amongst the brightest to date, SN 2023ixf is a young supernova, found earlier this year by amateur astronomer Kōichi Itagaki of Yamagata, Japan. This artists conception reveals the intense surge of SN 2023ixf, which occurred after an unforeseen quantity of mass loss unlike anything astronomers have actually seen before. Credit: Melissa Weiss/CfA
Within hours of going supernova, core-collapse supernovae produce a flash of light that occurs when the shock wave from the explosion reaches the outer edge of the star. SN 2023ixf, however, produced a light curve that didnt seem to fit this expected behavior. To better understand SN 2023ixfs shock breakout, a group of scientists led by CfA postdoctoral fellow Daichi Hiramatsu evaluated data from the 1.5 m Tillinghast Telescope, 1.2 m telescope, and MMT at the Fred Lawrence Whipple Observatory, a CfA center located in Arizona, in addition to information from the Global Supernova Project– an essential task of the Las Cumbres Observatory, NASAs Neil Gehrels Swift Observatory, and lots of others. This multi-wavelength research study, which was published today in The Astrophysical Journal Letters, exposed that, in sharp contradiction to expectations and outstanding advancement theory, SN 2023ixfs shock breakout was postponed by several days.
Ramifications of the Delayed Shock Breakout
” The postponed shock breakout is direct evidence for the presence of thick product from recent mass loss,” stated Hiramatsu, adding that such severe mass loss is irregular of Type II supernovae. “Our new observations exposed a unforeseen and considerable amount of mass loss– near to the mass of the Sun– in the last year prior to explosion.”
Recorded using the 1.2 m telescope at CfAs Fred Lawrence Whipple Observatory on June 27, 2023, simply over a month after SN 2023ixfs progenitor star exploded, the image in this composite combines together green, red, near-infrared, and infrared light to highlight both SN 2023ixf and the Pinwheel Galaxy. SN 2023ixf is located in among the spiral arms of the galaxy, as expected for the surges of huge stars. Credit: S. Gomez/STScI
SN 2023ixf challenges astronomers understanding of the evolution of massive stars and the supernovae they end up being. Researchers know that core-collapse supernovae are primary origin points for the cosmic formation and advancement of atoms, neutron stars, and black holes, really little is understood about the years leading up to stellar surges. The new observations point to possible instability in the final years of a stars life, resulting in extreme mass loss. This could be related to the final phases of nuclear burn-off of high-mass elements, like silicon, in the stars core.
Additional Observations and Collaboration
In combination with multi-wavelength observations led by Hiramatsu, Edo Berger, professor of astronomy at Harvard and CfA, and Hiramatsus advisor, performed millimeter-wave observations of the supernova utilizing CfAs Submillimeter Array (SMA) on the summit of Maunakea, Hawaii. These data, which are released in The Astrophysical Journal Letters, directly tracked the collision between the supernova particles and the thick material lost before the explosion. “SN 2023ixf took off precisely at the right time,” stated Berger. “Only a couple of days earlier we started a brand-new enthusiastic three-year program to study supernova explosions with the SMA, and this close-by interesting supernova was our very first target.”
” The only method to understand how huge stars act in the final years of their lives as much as the point of explosion is to find supernovae when they are extremely young, and preferably close by, and after that to study them throughout numerous wavelengths,” stated Berger. “Using both optical and millimeter telescopes we effectively turned SN 2023ixf into a time maker to rebuild what its progenitor star was doing up to the minute of its death.”
Significance of Amateur Astronomers
The supernova discovery itself, and the immediate follow-up, have significant significance to astronomers around the world, consisting of those doing science in their own yards. Itagaki found the supernova on May 19, 2023, from his personal observatory in Okayama, Japan.
” The partnership in between amateur and professional astronomers has an enduring custom of success in the supernova field,” stated Hiramatsu. “In the case of SN 2023ixf, I got an immediate e-mail from Kōichi Itagaki as quickly as he found SN 2023ixf. Without this relationship, and Itagakis work and dedication, we would have missed the opportunity to acquire vital understanding of the evolution of enormous stars and their supernova surges.”
Recommendations:
” From Discovery to the First Month of the Type II Supernova 2023ixf: High and Variable Mass Loss in the Final Year before Explosion” by Daichi Hiramatsu, Daichi Tsuna, Edo Berger, Koichi Itagaki, Jared A. Goldberg, Sebastian Gomez, Kishalay De, Griffin Hosseinzadeh, K. Azalee Bostroem, Peter J. Brown, Iair Arcavi, Allyson Bieryla, Peter K. Blanchard, Gilbert A. Esquerdo, Joseph Farah, D. Andrew Howell, Tatsuya Matsumoto, Curtis McCully, Megan Newsome, Estefania Padilla Gonzalez, Craig Pellegrino, Jaehyon Rhee, Giacomo Terreran, József Vinkó and J. Craig Wheeler, 19 September 2023, The Astrophysical Journal Letters.DOI: 10.3847/ 2041-8213/ acf299.
” Millimeter Observations of the Type II SN 2023ixf: Constraints on the Proximate Circumstellar Medium” by Edo Berger, Garrett K. Keating, Raffaella Margutti, Keiichi Maeda, Kate D. Alexander, Yvette Cendes, Tarraneh Eftekhari, Mark Gurwell, Daichi Hiramatsu, Anna Y. Q. Ho, Tanmoy Laskar, Ramprasad Rao and Peter K. G. Williams, 10 July 2023, The Astrophysical Journal Letters.DOI: 10.3847/ 2041-8213/ ace0c4.

In the year prior to going supernova the red supergiant star now understood as SN 2023ixf shed an unforeseen amount of mass equivalent to the mass of the Sun. One of the closest Type II supernovae in a decade and among the brightest to date, SN 2023ixf is a young supernova, found previously this year by amateur astronomer Kōichi Itagaki of Yamagata, Japan. Within hours of going supernova, core-collapse supernovae produce a flash of light that occurs when the shock wave from the surge reaches the external edge of the star. SN 2023ixf challenges astronomers understanding of the advancement of massive stars and the supernovae they end up being. “Only a couple of days previously we started a new enthusiastic three-year program to study supernova surges with the SMA, and this close-by interesting supernova was our very first target.”