Editing Supernova (section)

===Telescope findings===
With the development of the astronomical [[telescope]], observation and discovery of fainter and more distant supernovae became possible. The first such observation was of [[SN 1885A]] in the [[Andromeda Galaxy]]. A second supernova, [[SN 1895B]], was discovered in [[NGC 5253]] a decade later.<ref name=Schaefer1995>{{cite journal
 | title=The Peak Brightness of SN 1895B in NGC 5253 and the Hubble Constant
 | last=Schaefer | first=Bradley E.
 | journal=Astrophysical Journal Letters
 | volume=447 | page=L13 | date=July 1995
 | doi=10.1086/309549 | bibcode=1995ApJ...447L..13S | s2cid=227285055 | doi-access=free }}</ref> Early work on what was originally believed to be simply a new category of [[nova]]e was performed during the 1920s. These were variously called "upper-class Novae", "Hauptnovae", or "giant novae".<ref>{{cite book
 | title=Classifying the Cosmos: How We Can Make Sense of the Celestial Landscape
 | first=Steven J. | last=Dick | year=2019
 | page=191 | isbn=9783030103804
 | publisher=Springer International Publishing
 | url=https://books.google.com/books?id=UymODwAAQBAJ&pg=PA191
}}</ref> The name "supernovae" is thought to have been coined by [[Walter Baade]] and Zwicky in lectures at [[Caltech]] in 1931. It was used, as "super-Novae", in a journal paper published by [[Knut Lundmark]] in 1933,<ref name="baas33_1330">{{cite journal
 |last1=Osterbrock |first1=D. E.
 |year=2001
 |title=Who Coined the Word Supernova? Who First Predicted Neutron Stars?
 |journal=[[Bulletin of the American Astronomical Society]]
 |volume=33 |pages=1330
 |bibcode=2001AAS...199.1501O
}}</ref> and in a 1934 paper by Baade and Zwicky.<ref name="Baade1934">
{{cite journal |last1=Baade |first1=Walter |last2=Zwicky |first2=Fritz |date=1934 |title=On Super-novae |journal=[[Proceedings of the National Academy of Sciences]] |volume=20 |issue=5 |pages=254–259 |bibcode=1934PNAS...20..254B |doi=10.1073/pnas.20.5.254 |pmc=1076395 |pmid=16587881 |doi-access=free}}</ref> By 1938, the hyphen was no longer used and the modern name was in use.<ref>
{{cite book
 |last1=Murdin
 |first1=P.
 |last2=Murdin
 |first2=L.
 |year=1985
 |title=Supernovae
 |page=[https://archive.org/details/supernovae00murd/page/42 42]
 |edition=2nd
 |publisher=[[Cambridge University Press]]
 |isbn=978-0-521-30038-4
 |url=https://archive.org/details/supernovae00murd/page/42
 }}</ref>

American astronomers [[Rudolph Minkowski]] and [[Fritz Zwicky]] developed the modern supernova classification scheme beginning in 1941.<ref>
{{Cite journal
 |last=da Silva |first=L. A. L.
 |date=1993
 |title=The Classification of Supernovae
 |journal=[[Astrophysics and Space Science]]
 |volume=202 |issue=2 |pages=215–236
 |bibcode=1993Ap&SS.202..215D
 |doi=10.1007/BF00626878
|s2cid=122727067
 }}</ref> During the 1960s, astronomers found that the maximum intensities of supernovae could be used as [[standard candles]], hence indicators of astronomical distances.<ref>
{{Cite journal
 |last=Kowal |first=C. T.
 |date=1968
 |title=Absolute magnitudes of supernovae
 |journal=[[Astronomical Journal]]
 |volume=73 |pages=1021–1024
 |bibcode=1968AJ.....73.1021K
 |doi=10.1086/110763
|doi-access=free
 }}</ref> Some of the most distant supernovae observed in 2003 appeared dimmer than expected. This supports the view that the expansion of the [[Accelerating universe|universe is accelerating]].<ref name="Leibundgut">
{{cite journal
 |last1=Leibundgut |first1=B.
 |year=2003
 |title=A cosmological surprise: The universe accelerates
 |journal=Europhysics News
 |volume=32 |issue=4 |pages=121–125
 |bibcode=2001ENews..32..121L
 |doi=10.1051/epn:2001401
|doi-access=free
 }}</ref> Techniques were developed for reconstructing supernovae events that have no written records of being observed. The date of the Cassiopeia A supernova event was determined from light echoes off [[nebula]]e,<ref>
{{Cite journal
 |last=Fabian |first=A. C.
 |date=2008
 |title=A Blast from the Past
 |journal=[[Science (journal)|Science]]
 |volume=320 |issue=5880 |pages=1167–1168
 |doi=10.1126/science.1158538
 |pmid=18511676
|s2cid=206513073
 }}</ref> while the age of supernova remnant [[RX J0852.0-4622]] was estimated from temperature measurements<ref>
{{Cite journal
 |last=Aschenbach |first=B.
 |date=1998
 |title=Discovery of a young nearby supernova remnant
 |journal=[[Nature (journal)|Nature]]
 |volume=396 |issue=6707 |pages=141–142
 |bibcode=1998Natur.396..141A
 |doi=10.1038/24103
|s2cid=4426317
 }}</ref> and the [[gamma ray]] emissions from the radioactive decay of [[titanium-44]].<ref>
{{Cite journal
 |last1=Iyudin |first1=A. F.
 |last2=Schönfelder |first2=V.
 |last3=Bennett |first3=K.
 |last4=Bloemen |first4=H.
 |last5=Diehl |first5=R.
 |last6=Hermsen |first6=W.
 |last7=Lichti |first7=G. G.
 |last8=Van Der Meulen |first8=R. D.
 |last9=Ryan |first9=J.
 |last10=Winkler |first10=C.
 |date=1998
 |title=Emission from <sup>44</sup>Ti associated with a previously unknown Galactic supernova
 |journal=[[Nature (journal)|Nature]]
 |volume=396 |issue=6707 |pages=142–144
 |bibcode=1998Natur.396..142I
 |doi=10.1038/24106
|s2cid=4430526
 }}</ref>

[[File:Jades Deep Field Annotated.png|thumb|upright=1.2|Jades Deep Field. A team of astronomers studying JADES data identified about 80 objects (circled in green) that changed in brightness over time. Most of these objects, known as transients, are the result of exploding stars or supernovae.<ref>{{cite web |title=NASA's Webb Opens New Window on Supernova Science - NASA Science |url=https://science.nasa.gov/missions/webb/nasas-webb-opens-new-window-on-supernova-science |website=science.nasa.gov |date=10 June 2024 |access-date=11 June 2024}}</ref>]]

The most luminous supernova ever recorded is [[ASASSN-15lh]], at a distance of 3.82 [[light-year|gigalight-years]]. It was first detected in June 2015 and peaked at {{solar luminosity|570 billion|link=y}}, which is twice the [[bolometric luminosity]] of any other known supernova.<ref>{{Cite journal
 | last1=Dong | first1=Subo | last2=Shappee | first2=B. J.
 | last3=Prieto | first3=J. L. | last4=Jha | first4=S. W.
 | last5=Stanek | first5=K. Z. | last6=Holoien | first6=T. W. -S.
 | last7=Kochanek | first7=C. S. | last8=Thompson | first8=T. A.
 | last9=Morrell | first9=N. | last10=Thompson | first10=I. B.
 | last11=Basu | first11=U. | last12=Beacom | first12=J. F.
 | last13=Bersier | first13=D. | last14=Brimacombe | first14=J.
 | last15=Brown | first15=J. S. | last16=Bufano | first16=F.
 | last17=Chen | first17=Ping | last18=Conseil | first18=E.
 | last19=Danilet | first19=A. B. | last20=Falco | first20=E.
 | last21=Grupe | first21=D. | last22=Kiyota | first22=S.
 | last23=Masi | first23=G. | last24=Nicholls | first24=B.
 | last25=Olivares E. | first25=F. | last26=Pignata | first26=G.
 | last27=Pojmanski | first27=G. | last28=Simonian | first28=G. V.
 | last29=Szczygiel | first29=D. M. | last30=Woźniak | first30=P. R.
 | title=ASASSN-15lh: A highly super-luminous supernova
 | journal=Science | year=2016 | s2cid=31444274
 | volume=351 | issue=6270 | pages=257–260
 | arxiv=1507.03010 | bibcode=2016Sci...351..257D
 | doi=10.1126/science.aac9613 | pmid=26816375
}}</ref> The nature of this supernova is debated and several alternative explanations, such as tidal disruption of a star by a black hole, have been suggested.<ref>
{{Cite journal
 | title=The superluminous transient ASASSN-15lh as a tidal disruption event from a Kerr black hole
 | last1=Leloudas | first1=G. | last2=Fraser | first2=M.
 | last3=Stone | first3=N. C. | last4=van Velzen | first4=S.
 | last5=Jonker | first5=P. G. | last6=Arcavi | first6=I.
 | last7=Fremling | first7=C. | last8=Maund | first8=J. R.
 | last9=Smartt | first9=S. J. | last10=Krìhler | first10=T.
 | last11=Miller-Jones | first11=J. C. A. | last12=Vreeswijk | first12=P. M.
 | last13=Gal-Yam | first13=A. | last14=Mazzali | first14=P. A.
 | last15=De Cia | first15=A. | last16=Howell | first16=D. A.
 | last17=Inserra | first17=C. | last18=Patat | first18=F.
 | last19=de Ugarte Postigo | first19=A. | last20=Yaron | first20=O.
 | last21=Ashall | first21=C. | last22=Bar | first22=I.
 | last23=Campbell | first23=H. | last24=Chen | first24=T. -W.
 | last25=Childress | first25=M. | last26=Elias-Rosa | first26=N.
 | last27=Harmanen | first27=J. | last28=Hosseinzadeh | first28=G.
 | last29=Johansson | first29=J. | last30=Kangas | first30=T.
 | last31=Kankare | first31=E. | last32=Kim | first32=S.
 | last33=Kuncarayakti | first33=H. | last34=Lyman | first34=J.
 | last35=Magee | first35=M. R. | last36=Maguire | first36=K.
 | last37=Malesani | first37=D. | last38=Mattila | first38=S.
 | last39=McCully | first39=C. V. | last40=Nicholl | first40=M.
 | last41=Prentice | first41=S. | last42=Romero-Cañizales | first42=C.
 | last43=Schulze | first43=S. | last44=Smith | first44=K. W.
 | last45=Sollerman | first45=J. | last46=Sullivan | first46=M.
 | last47=Tucker | first47=B. E. | last48=Valenti | first48=S.
 | last49=Wheeler | first49=J. C. | last50=Young | first50=D. R. | display-authors=1
 | journal=Nature Astronomy | year=2016
 | volume=1 | issue=2 | page=0002
 | arxiv=1609.02927 | bibcode=2016NatAs...1E...2L
 | doi=10.1038/s41550-016-0002 | s2cid=73645264
}}</ref>

[[SN 2013fs]] was recorded three hours after the supernova event on 6 October 2013, by the [[Palomar Transient Factory|Intermediate Palomar Transient Factory]]. This is among the earliest supernovae caught after detonation, and it is the earliest for which spectra have been obtained, beginning six hours after the actual explosion. The star is located in a [[spiral galaxy]] named [[NGC 7610]], 160&nbsp;million light-years away in the constellation of Pegasus.<ref>
{{Cite news
 |last=Sample |first=I.
 |date=13 February 2017
|title=Massive supernova visible millions of light-years from Earth
 |url=https://www.theguardian.com/science/2017/feb/13/massive-supernova-visible-millions-of-light-years-from-earth
 |newspaper=The Guardian
 |access-date=13 February 2017
|url-status=live
 |archive-url=https://web.archive.org/web/20170213172456/https://www.theguardian.com/science/2017/feb/13/massive-supernova-visible-millions-of-light-years-from-earth
 |archive-date=13 February 2017
}}</ref><ref>
{{Cite journal
 |last1=Yaron |first1=O.
 |last2=Perley |first2=D. A.
 |last3=Gal-Yam |first3=A.
 |last4=Groh |first4=J. H.
 |last5=Horesh |first5=A.
 |last6=Ofek |first6=E. O.
 |last7=Kulkarni |first7=S. R.
 |last8=Sollerman |first8=J.
 |last9=Fransson |first9=C.
 |date=13 February 2017
|title=Confined dense circumstellar material surrounding a regular type II supernova
 |journal=Nature Physics
 |volume= 13|issue=5 |pages=510–517
 |arxiv=1701.02596
 |bibcode=2017NatPh..13..510Y
 |doi=10.1038/nphys4025
|s2cid=29600801
 }}</ref>

The supernova [[SN 2016gkg]] was detected by amateur astronomer Victor Buso from [[Rosario]], Argentina, on 20 September 2016.<ref name=AS_Now>{{cite magazine
 |author=Astronomy Now journalist
 |date=23 February 2018
|title=Amateur astronomer makes once-in-lifetime discovery
 |magazine=[[Astronomy Now]]
 |url=https://astronomynow.com/2018/02/23/amateur-astronomer-makes-once-in-lifetime-discovery
 |access-date=15 May 2018
|archive-date=16 May 2018
|archive-url=https://web.archive.org/web/20180516174620/https://astronomynow.com/2018/02/23/amateur-astronomer-makes-once-in-lifetime-discovery/
 |url-status=live
 }}</ref><ref name=NatBuso>
{{cite journal
 |last1=Bersten |first1=M. C.
 |last2=Folatelli |first2=G.
 |last3=García |first3=F.
 |last4=Van Dyk |first4=S. D.
 |last5=Benvenuto |first5=O. G.
 |last6=Orellana |first6=M.
 |last7=Buso |first7=V.
 |last8=Sánchez |first8=J. L.
 |last9=Tanaka |first9=M.
 |last10=Maeda |first10=K.
 |last11=Filippenko |first11=A. V.
 |last12=Zheng |first12=W.
 |last13=Brink |first13=T. G.
 |last14=Cenko |first14=S. B.
 |last15=De Jaeger |first15=T.
 |last16=Kumar |first16=S.
 |last17=Moriya |first17=T. J.
 |last18=Nomoto |first18=K.
 |last19=Perley |first19=D. A.
 |last20=Shivvers |first20=I.
 |last21=Smith |first21=N.
 |date=21 February 2018
|title=A surge of light at the birth of a supernova
 |journal=[[Nature (journal)|Nature]]
 |volume=554 |issue=7693 |pages=497–499
 |arxiv=1802.09360
 |bibcode=2018Natur.554..497B
 |doi=10.1038/nature25151
 |pmid=29469097
|s2cid=4383303
 }}</ref> It was the first time that the initial "shock breakout" from an optical supernova had been observed.<ref name=AS_Now/> The progenitor star has been identified in [[Hubble Space Telescope]] images from before its collapse. Astronomer [[Alex Filippenko]] noted: "Observations of stars in the first moments they begin exploding provide information that cannot be directly obtained in any other way."<ref name=AS_Now/>