Astronomy:SN 2021yfj
 A green-light light curve for SN 2021yfj, plotted from data published by Schulze et al..[1] The red arrows show upper limits from nondetections. | |
| Event type | Supernova |
|---|---|
| Spectral class | Ien |
| Date | 2021 |
| Right ascension | 01h 37m 46.17s |
| Declination | 24.442, -1.2549 |
| Epoch | J2000 |
| Distance | 2.2 billion ly |
| Notable features | Unusual spectra |
SN 2021yfj was a Type Ien supernova event known to potentially be the first supernova discovered of its type.[2] It occurred roughly 2.2 billion light years from Earth in the host galaxy SDSS J013746.19-011518.6.[3][4]
The progenitor star of SN 2021yfj was stripped of its oxygen, silicon and sulfur rich-layer with evidence that it had been expelled a massive, thick layer of silicon and sulfur before it had gone supernova. Exposing such an inner stellar layer is theoretically challenging and probably requires a rarely observed mass-loss mechanism. Early spectra taken of SN 2021yfj was unique in that its emission lines were dominated by prominent emission lines of highly ionized silicon, sulphur and argon while lacking prominent features from carbon, oxygen, helium and hydrogen.[3][1]
There are several scenarios for the nature of the progenitor star of SN 2021yfj. The first scenario is that it was a high mass massive star that when it has gone supernova, its shell of material collided with each other before collapsing into a black hole. The second scenario is that it was a low mass massive star and the third scenario being a merger of two compact objects such was white dwarf or neutron stars.[5]
History
It was first seen at 09:56 UTC on September 7, 2021 by the Zwicky Transient Facility.[1][6] It has been proposed that SN 2021yfj should be placed into its own classification type known as SN len based on its unique spectra. This would also leave a placeholder intermediate type of supernova known as SN idn. This possible type would have spectra that were dominated in either oxygen, neon or magnesium.[2]
See also
References
- ↑ 1.0 1.1 1.2 Schulze, Steve; Gal-Yam, Avishay; Dessart, Luc; Miller, Adam A.; Woosley, Stan E.; Yang, Yi; Bulla, Mattia; Yaron, Ofer et al. (August 2025). "Extremely stripped supernova reveals a silicon and sulfur formation site" (in en). Nature 644 (8077): 634–639. doi:10.1038/s41586-025-09375-3. ISSN 1476-4687. PMID 40836132. Bibcode: 2025Natur.644..634S. https://www.nature.com/articles/s41586-025-09375-3.
- ↑ 2.0 2.1 Gal-Yam, A.; Yaron, O.; Schulze, S. (September 2024). "Introducing a new supernova classification type: SN Ien" (in en). Transient Name Server AstroNote 239: 1. Bibcode: 2024TNSAN.239....1G. https://ui.adsabs.harvard.edu/abs/2024TNSAN.239....1G/abstract.
- ↑ 3.0 3.1 Gough, Evan; Today, Universe. "The exposed core of this supernova is a head-scratcher" (in en). https://phys.org/news/2025-08-exposed-core-supernova-scratcher.html.
- ↑ "2021yfj | Transient Name Server". https://www.wis-tns.org/object/2021yfj.
- ↑ Schulze, Steve; Gal-Yam, Avishay; Dessart, Luc; Miller, Adam A.; Woosley, Stan E.; Yang, Yi; Bulla, Mattia; Yaron, Ofer et al. (2025-08-28). "Extremely stripped supernova reveals a silicon and sulfur formation site". Nature 644 (8077): 634–639. doi:10.1038/s41586-025-09375-3. PMID 40836132. Bibcode: 2025Natur.644..634S.
- ↑ O'Callaghan, Jonathon (20 August 2025). "Onionlike Space Explosion May Be a New Type of Supernova". https://www.nytimes.com/2025/08/20/science/supernova-layers-elements.html.
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