{{Short description|Extragalactic supernova in 2020}} {{Infobox astronomical event | name = SN 2020oi | image = SN2020oiLightCurve.png | image_size = | caption = 2020 [[light curve]]s for SN 2020oi in four [[Photometric_system#Photometric_letters|photometric bands]], adapted from Rho ''et al.'' (2021)<ref name=Rho_et_al_2021/> | alt = | names = | event_type = Supernova | class = Type Ic<ref name=Horesh_et_al_2020/> | start_time = January 7, 2020<ref name=Horesh_et_al_2020/> | duration = | detected_by = ZTF<ref name=TNS/> | constellation = [[Coma Berenices]] | ra = {{RA|12|22|54.925}}<ref name=TNS/> | dec = {{DEC|+15|49|25.05}}<ref name=TNS/> | epoch = [[J2000]] | gal = | distance = {{cvt|14|Mpc|Mly|order=flip|lk=on}}<ref name=Horesh_et_al_2020/> | redshift = | source = | remnant = | host = Messier 100<ref name=Horesh_et_al_2020/> | progenitor = | progenitor_type = Envelope-stripped massive star<ref name=Rho_et_al_2021/> | b-v = | notes = | peak = 17.28<ref name=TNS/> | energy = {{val|e=51|ul=erg|p=~}}<ref name=Rho_et_al_2021/> | website = | predecessor = | successor = | commons = | embedded = }}
'''SN 2020oi''' was a [[supernova]] event in the [[grand design spiral galaxy]] known as [[Messier 100]], or NGC 4321. It was discovered January 7, 2020 at an [[apparent magnitude]] of 17.28 by F. Forster and associates using the [[Zwicky Transient Facility]]. The position places it {{val|4.67|ul=arcsecond|p=~}} north of the [[galactic nucleus]].<ref name=Gagliano_et_al_2022/> The supernova was not detected on an observation made three days before the discovery, and thus it must have begun during that brief period.<ref name=Horesh_et_al_2020/> The [[light curve]] peaked around January 13–18, depending on the [[wavelength]], then declined rapidly over a period of 25 days before flattening into a more gradual decline.<ref name=Rho_et_al_2021/> Observations of the [[stellar spectrum|spectrum]] made with the [[Southern Astrophysical Research Telescope|SOAR telescope]] showed this to be a [[type Ic supernova]], with the progenitor being a massive star that had its outer envelope stripped. The initial velocity of the expanding [[photosphere]] was {{val|15000|u=km/s|p=~|fmt=commas}}.<ref name=Horesh_et_al_2020/>
Models of the event give an initial ([[zero age main sequence]]) estimated mass of {{val|9.5|1.0|ul=solar mass}}<ref name=Gagliano_et_al_2022/> or {{val|13|ul=solar mass}}<ref name=Rho_et_al_2021/> for the progenitor. It was a member of a [[binary star]] system and lost its outer envelope of hydrogen and helium due to interaction with its companion. The resulting helium-poor star was primarily made of carbon and oxygen with a mass of about {{val|2.16|u=solar mass}}. The supernova explosion was the result of a collapse of an inert iron [[stellar core|core]]. The event ejected {{val|0.71|u=solar mass}} of material and left behind a [[neutron star]] remnant with a presumed mass of {{val|1.45|u=solar mass}}. The explosion released about {{val|e=51|ul=erg}} of energy, of which 60% was expended on [[kinetic energy]].<ref name=Rho_et_al_2021/>
This is one of the few type Ic supernovae for which [[radio astronomy|radio]] emission has been detected. Based on this data, the [[shock wave]] from the explosion advanced through the surrounding interstellar matter with a velocity of 3−{{val|4|e=4|u=km/s}}. In order to produce the observed emission, the progenitor star underwent mass loss at an average rate of {{val|1.4|e=−4|u=solar mass}}·yr<sup>−1</sup> at a typical wind velocity of {{val|1000|u=km/s|fmt=commas|p=~}}.<ref name=Horesh_et_al_2020/> Images of the location taken prior to the event using the [[Hubble Space Telescope]] show a [[stellar cluster]] at that location.<ref name=Gagliano_et_al_2022/>
==References== <references> <ref name=TNS>{{citation | title=SN 2020oi | website=Transient Name Server | url=https://www.wis-tns.org/object/2020oi | access-date=2022-01-20 | postscript=. }}</ref>
<ref name=Horesh_et_al_2020>{{citation | title=A Non-equipartition Shock Wave Traveling in a Dense Circumstellar Environment around SN 2020oi | last1=Horesh | first1=Assaf | last2=Sfaradi | first2=Itai | last3=Ergon | first3=Mattias | last4=Barbarino | first4=Cristina | last5=Sollerman | first5=Jesper | last6=Moldon | first6=Javier | last7=Dobie | first7=Dougal | last8=Schulze | first8=Steve | last9=Pérez-Torres | first9=Miguel | last10=Williams | first10=David R. A. | last11=Fremling | first11=Christoffer | last12=Gal-Yam | first12=Avishay | last13=Kulkarni | first13=Shrinivas R. | last14=O'Brien | first14=Andrew | last15=Lundqvist | first15=Peter | last16=Murphy | first16=Tara | last17=Fender | first17=Rob | last18=Anand | first18=Shreya | last19=Belicki | first19=Justin | last20=Bellm | first20=Eric C. | last21=Coughlin | first21=Michael W. | last22=De | first22=Kishalay | last23=Golkhou | first23=V. Zach | last24=Graham | first24=Matthew J. | last25=Green | first25=Dave A. | last26=Hankins | first26=Matt | last27=Kasliwal | first27=Mansi | last28=Kupfer | first28=Thomas | last29=Laher | first29=Russ R. | last30=Masci | first30=Frank J. | last31=Miller | first31=A. A. | last32=Neill | first32=James D. | last33=Ofek | first33=Eran O. | last34=Perrott | first34=Yvette | last35=Porter | first35=Michael | last36=Reiley | first36=Daniel J. | last37=Rigault | first37=Mickael | last38=Rodriguez | first38=Hector | last39=Rusholme | first39=Ben | last40=Shupe | first40=David L. | last41=Titterington | first41=David | display-authors=1 | journal=The Astrophysical Journal | postscript=. | volume=903 | issue=2 | id=132 | pages=15 | date=November 2020 | doi=10.3847/1538-4357/abbd38 | arxiv=2006.13952 | bibcode=2020ApJ...903..132H | s2cid=220055590 | doi-access=free }}</ref>
<ref name=Rho_et_al_2021>{{citation | title=Near-infrared and Optical Observations of Type Ic SN 2020oi and Broad-lined Type Ic SN 2020bvc: Carbon Monoxide, Dust, and High-velocity Supernova Ejecta | last1=Rho | first1=J. | last2=Evans | first2=A. | last3=Geballe | first3=T. R. | last4=Banerjee | first4=D. P. K. | last5=Hoeflich | first5=P. | last6=Shahbandeh | first6=M. | last7=Valenti | first7=S. | last8=Yoon | first8=S. -C. | last9=Jin | first9=H. | last10=Williamson | first10=M. | last11=Modjaz | first11=M. | last12=Hiramatsu | first12=D. | last13=Howell | first13=D. A. | last14=Pellegrino | first14=C. | last15=Vinkó | first15=J. | last16=Cartier | first16=R. | last17=Burke | first17=J. | last18=McCully | first18=C. | last19=An | first19=H. | last20=Cha | first20=H. | last21=Pritchard | first21=T. | last22=Wang | first22=X. | last23=Andrews | first23=J. | last24=Galbany | first24=L. | last25=Van Dyk | first25=S. | last26=Graham | first26=M. L. | last27=Blinnikov | first27=S. | last28=Joshi | first28=V. | last29=Pál | first29=A. | last30=Kriskovics | first30=L. | last31=Ordasi | first31=A. | last32=Szakats | first32=R. | last33=Vida | first33=K. | last34=Chen | first34=Z. | last35=Li | first35=X. | last36=Zhang | first36=J. | last37=Yan | first37=S. | display-authors=1 | journal=The Astrophysical Journal | postscript=. | volume=908 | issue=2 | id=232 | pages=21 | date=February 2021 | doi=10.3847/1538-4357/abd850 | arxiv=2010.00662 | bibcode=2021ApJ...908..232R | s2cid=222125057 | doi-access=free }}</ref>
<ref name=Gagliano_et_al_2022>{{citation | title=An Early-time Optical and Ultraviolet Excess in the Type-Ic SN 2020oi | last1=Gagliano | first1=Alexander | last2=Izzo | first2=Luca | last3=Kilpatrick | first3=Charles D. | last4=Mockler | first4=Brenna | last5=Jacobson-Galán | first5=Wynn Vicente | last6=Terreran | first6=Giacomo | last7=Dimitriadis, Georgios | last8=Zenati | first8=Yossef | last9=Auchettl | first9=Katie | last10=Drout | first10=Maria R. | last11=Narayan | first11=Gautham | last12=Foley | first12=Ryan J. | last13=Margutti | first13=R. | last14=Rest | first14=Armin | last15=Jones | first15=D. O. | last16=Aganze | first16=Christian | last17=Aleo | first17=Patrick D. | last18=Burgasser | first18=Adam J. | last19=Coulter | first19=D. A. | last20=Gerasimov | first20=Roman | last21=Gall | first21=Christa | last22=Hjorth | first22=Jens | last23=Hsu | first23=Chih-Chun | last24=Magnier | first24=Eugene A. | last25=Mandel | first25=Kaisey S. | last26=Piro | first26=Anthony L. | last27=Rojas-Bravo | first27=César | last28=Siebert | first28=Matthew R. | last29=Stacey | first29=Holland | last30=Stroh | first30=Michael Cullen | last31=Swift | first31=Jonathan | last32=Taggart | first32=Kirsty | last33=Tinyanont | first33=Samaporn | last34=Tinyanont | first34=Samaporn | display-authors=1 | journal=The Astrophysical Journal | volume=924 | issue=2 | id=55 | pages=29 | postscript=. | date=January 2022 | doi=10.3847/1538-4357/ac35ec | arxiv=2105.09963 | bibcode=2022ApJ...924...55G | s2cid=235125935 | doi-access=free }}</ref> </references>
==Further reading== {{Div col|small=yes}} *{{citation | title=Optical spectrum of SN 2020oi (ZTF20aaelulu) | last1=Dutta | first1=Anirban | last2=Kumar | first2=Brajesh | last3=Anupama | first3=G. C. | last4=Sahu | first4=Devendra | last5=Sujith | first5=D. S. | last6=Singh | first6=Avinash | display-authors=1 | journal=The Astronomer's Telegram | number=13404 | date=January 2020 | volume=13404 | page=1 | bibcode=2020ATel13404....1D | postscript=. }} *{{citation | title=An Initial Analysis of the VLA Observation of the Nearby Supernova SN2020oi in M100 | last1=Horesh | first1=A. | last2=Sfaradi | first2=I. | journal=The Astronomer's Telegram | number=13398 | date=January 2020 | volume=13398 | page=1 | bibcode=2020ATel13398....1H | postscript=. }} *{{citation | title=AMI-LA 15.5 GHz Observations of the Nearby Supernova SN2020oi | display-authors=1 | last1=Sfaradi | first1=Itai | last2=Williams | first2=David | last3=Horesh | first3=Assaf | last4=Fender | first4=Rob | last5=Green | first5=Dave | last6=Titterington | first6=David | last7=Perrott | first7=Yvette | journal=The Astronomer's Telegram | number=13401 | date=January 2020 | volume=13401 | page=1 | bibcode=2020ATel13401....1S | postscript=. }} *{{citation | title=e-MERLIN radio detection of SN 2020oi at 5 GHz | display-authors=1 | last1=Moldon | first1=J. | last2=Horesh | first2=A. | last3=Perez-Torres | first3=M. | last4=Sfaradi | first4=I. | last5=Lundqvist | first5=P. | journal=The Astronomer's Telegram | number=13448 | date=February 2020 | volume=13448 | page=1 | bibcode=2020ATel13448....1M | postscript=. }} *{{cite journal |mode=cs2 | title=The Final Months of Massive Star Evolution from the Circumstellar Environment around SN Ic 2020oi | first1=Keiichi | last1=Maeda | first2=Poonam | last2=Chandra | first3=Tomoki | last3=Matsuoka | first4=Stuart | last4=Ryder | first5=Takashi J. | last5=Moriya | first6=Hanindyo | last6=Kuncarayakti | first7=Shiu-Hang | last7=Lee | first8=Esha | last8=Kundu | first9=Daniel | last9=Patnaude | first10=Tomoki | last10=Saito | first11=Gaston | last11=Folatelli | journal=The Astrophysical Journal | display-authors=1 | date=June 22, 2021 | volume=918 | issue=1 | page=34 | doi=10.3847/1538-4357/ac0dbc | arxiv=2106.11618 | bibcode=2021ApJ...918...34M | s2cid=235592953 | doi-access=free }} *{{citation | title=Infrared spectropolarimetric detection of intrinsic polarization from a core-collapse supernova | last1=Tinyanont | first1=Samaporn | last2=Millar-Blanchaer | first2=Maxwell | last3=Kasliwal | first3=Mansi M. | last4=Mawet | first4=Dimitri | last5=Leonard | first5=Douglas C. | last6=Bulla | first6=Mattia | last7=De | first7=Kishalay | last8=Jovanovic | first8=Nemanja | last9=Hankins | first9=Matthew | last10=Vasisht | first10=Gautam | last11=Serabyn, Eugene | display-authors=1 | journal=Nature Astronomy | volume=5 | pages=544–551 | date=2021 | issue=6 | doi=10.1038/s41550-021-01320-4 | arxiv=2102.02075 | bibcode=2021NatAs...5..544T | s2cid=231786458 | postscript=. }} {{Div col end}}
{{Supernovae}} {{Coma Berenices}}
[[Category:Supernovae]] [[Category:Messier 100]] [[Category:Coma Berenices]] [[Category:Astronomical objects discovered in 2020]]