ASASSN-15lh
| Hypernova | |
| Constellation | Indus |
|---|---|
| Right ascension | 22h 2m 15.45s[1] |
| Declination | −69° 39′ 34.64″[1] |
| Epoch | J2000 |
| Distance | 3.8 billion light years |
| Redshift | 0.2326  |
ASASSN-15lh (also designated SN 2015L) is a superluminous supernova that was detected by the All Sky Automated Survey for SuperNovae (ASAS-SN) in 2015 in the southern constellation Indus.[1] The discovery, confirmed by ASAS-SN group with several other telescopes,[1] was formally described and published on 15 January 2016. ASASSN-15lh is the most luminous supernova ever detected; at its brightest it was at least 20 times brighter than the whole Milky Way,[2] with an energy hundreds of billions times greater than the Sun.[3] The peak absolute magnitude was −23.5, putting out 2×1047 ergs per second. Energy radiated exceeded 1052 ergs. The supernova was at redshift 0.2326, in a stagnant but luminous galaxy[4] some 3.8 billion light years from Earth.[3] According to Krzysztof Stanek of Ohio State University, one of the principal investigators at ASAS-SN, "If it was in our own galaxy, it would shine brighter than the full moon; there would be no night, and it would be easily seen during the day."[5]
Discovery
ASASSN-15lh was first captured in June 2015 by ASAS-SN’s twin 14-cm telescopes in Chile.[6] The supernova appeared as a transient dot of light on an image and confirmed with additional observations from other telescopes.[6] The observations detected the outburst’s fading afterglow, while the spectrum of ASASSN-15lh was provided by the 2.5-meter du Pont Telescope in Chile.[6] At its peak, ASASSN-15lh was twice as luminous as the previous brightest superluminous supernova, iPTF13ajg.[7]
Previously observed superluminous supernovae (known as SLSNe) have been discovered in relatively small and "busy" star-producing galaxies, in contrast to ASASSN-15lh, which lies in a large and relatively calm galaxy of a type not previously known for producing superluminous supernovae.[8] Such explosions are 100 to 1,000 times as powerful as typical supernovae. Although the precise mechanism underlying the very large ASASSN-15lh explosion is still unknown, with speculation ranging from the presence of very large quantities of decaying nickel to the amplifying effects of a magnetar, its unusual location in a relatively quiescent galaxy may offer clues for scientists to discover and observe similar events.[8]
References
- ^ a b c d Monica Young (July 12, 2015). "The Most Luminous Supernova". Sky & Telescope. Retrieved 16 Jan 2016.
- ^ Carnegie Institution for Science (14 January 2016). "Most-luminous supernova ever discovered". phys.org. Retrieved 15 January 2016.
- ^ a b Bhanoo, Sindya N. (January 15, 2016). "Supernova Has Energy of Hundreds of Billions of Suns". The New York Times. Retrieved January 16, 2016.
- ^ Dong, S.; Shappee, B. J.; Prieto, J. L.; Jha, S. W.; Stanek, K. Z.; Holoien, T. W.- S.; Kochanek, C. S.; Thompson, T. A.; Morrell, N.; Thompson, I. B.; et al. (14 January 2016). "ASASSN-15lh: A highly super-luminous supernova". Science. 351 (6270): 257–260. arXiv:1507.03010. doi:10.1126/science.aac9613.
{{cite journal}}: no-break space character in|last30=at position 3 (help) - ^ Boyle, Rebecca (January 14, 2016). "We've found the brightest ever supernova but can't explain it". New Scientist. Retrieved January 15, 2016.
- ^ a b c Lee Billings (January 14, 2016). "Found: The Most Powerful Supernova Ever Seen". Scientific American. Retrieved January 16, 2016.
- ^ Monica Young (January 15, 2016). "Brightest Supernova Baffles Astronomers". Sky & Telescope. Retrieved January 16, 2016.
- ^ a b Thomson, Jason (January 14, 2016). "Astronomers spot brightest supernova in history". The Christian Science Monitor. Retrieved January 15, 2016.
Further reading
- Cowen, Ron (14 January 2016). "Brightest-ever supernova still baffles astronomers". Nature. doi:10.1038/nature.2016.19176.
- Parnell, Brid-Aine. "Superluminous Supernova Is The Brightest Ever Seen". Forbes. Retrieved 15 January 2016.