SN 2008D

{{ Supernova |

| name = SN 2008D

| image = 250px

| caption= X-ray (left) and visible light (right) images of SN 2008D (1), and SN 2007uy (2).

| type = Ibc

| epoch = J2000

| SNRtype =

| host = NGC 2770

| constellation = Lynx

| ra = {{RA|09|09|30.55}}

| dec = {{DEC|+33|08|20.81}}

| gal = 191.5472 +42.1883

| discovery = January 9, 2008

| iauc =

| mag_v =

| distance = {{convert|27|Mpc|Mly|abbr=on|lk=on}}

| progenitor = Unknown

| progenitor_type = Unknown

| b-v = Unknown

| notes = First supernova detected by the X-rays released very early on in its formation.

}}

Image:211875main2 beflabelsnova 20080213 350px.jpg before SN 2008D, with X-ray view (left) and visible light (right).]]

SN 2008D is a supernova detected with NASA's Swift X-ray telescope. The explosion of the supernova precursor star, in the spiral galaxy NGC 2770 (88 million light years away (27 Mpc), was detected on January 9, 2008, by Carnegie-Princeton fellows Alicia Soderberg and Edo Berger, and Albert Kong and Tom Maccarone independently using Swift.{{ citation

| last1 = Soderberg

| first1 = Alicia

| last2 = Berger

| first2 = Edo

| last3 = Page

| first3 = K. L.

| last4 = Schady

| first4 = P.|author4-link= Patricia Schady

| last5 = Parrent

| first5 = J.

| last6 = Pooley

| first6 = D.

| last7 = Wang

| first7 = X.-Y.

| last8 = Ofek

| first8 = E. O.

| last9 = Cucchiara

| first9 = A.

| last10 = Rau

| first10 = A.

| last11 = Waxman

| first11 = E.

| last12 = Simon

| first12 = J. D.

| last13 = Bock

| first13 = D. C.-J.

| last14 = Milne

| first14 = P. A.

| last15 = Page

| first15 = M. J.

| last16 = Barentine

| first16 = J. C.

| last17 = Barthelmy

| first17 = S. D.

| last18 = Beardmore

| first18 = A. P.

| last19 = Bietenholz

| first19 = M. F.

| last20 = Brown

| first20 = P.

| last21 = Burrows

| first21 = A.

| last22 = Burrows

| first22 = D. N.

| last23 = Byrngelson

| first23 = G.

| last24 = Cenko

| first24 = S. B.

| last25 = Chandra

| first25 = P.

| last26 = Cummings

| first26 = J. R.

| last27 = Fox

| first27 = D. B.

| last28 = Gal-Yam

| first28 = A.

| last29 = Gehrels

| first29 = N.

| last30 = Immler

| first30 = S.

| year = 2008

| title = An extremely luminous X-ray outburst at the birth of a supernova

| journal = Nature

| volume = 453

| issue = 7194

| pages = 469–474

| doi = 10.1038/nature06997

| arxiv = 0802.1712

| pmid = 18497815

| bibcode = 2008Natur.453..469S | s2cid = 453215

| display-authors = 8

}} They alerted eight other orbiting and ground-based observatories to record the event. This was the first time that astronomers have ever observed a supernova as it occurred.{{cite web|title=SN 2008D: First Supernova Observed Live|url=http://www.universeforfacts.com/2014/01/sn-2008d-first-supernova-observed-live.html|archive-url=https://web.archive.org/web/20141221205714/http://www.universeforfacts.com/2014/01/sn-2008d-first-supernova-observed-live.html|url-status=usurped|archive-date=December 21, 2014|website=Universe for Facts|accessdate=21 December 2014}}{{cite web|url=https://www.sciencedaily.com/releases/2008/05/080521131549.htm|title=Supernova Birth Seen For First Time|website=ScienceDaily|date=21 May 2008}}{{cite journal|url=http://blogs.discovermagazine.com/badastronomy/2008/05/21/birth-cry-of-a-supernova/|title=Birth cry of a supernova|date=21 May 2008|journal=Discover Magazine|access-date=12 October 2008|archive-date=20 July 2008|archive-url=https://web.archive.org/web/20080720045638/http://blogs.discovermagazine.com/badastronomy/2008/05/21/birth-cry-of-a-supernova/|url-status=dead}}

File:SN2008DLightCurve.png, plotted from data published by Malesani et al. (2009){{cite journal |last1=Malesani |first1=D. |last2=Fynbo |first2=J. P. U. |last3=Hjorth |first3=J. |last4=Leloudas |first4=G. |last5=Sollerman |first5=J. |last6=Stritzinger |first6=M. D. |last7=Vreeswijk |first7=P. M. |last8=Watson |first8=D. J. |last9=Gorosabel |first9=J. |last10=Michaowski |first10=M. J. |last11=Thöne |first11=C. C. |last12=Augusteijn |first12=T. |last13=Bersier |first13=D. |last14=Jakobsson |first14=P. |last15=Jaunsen |first15=A. O. |last16=Ledoux |first16=C. |last17=Levan |first17=A. J. |last18=Milvang-Jensen |first18=B. |last19=Rol |first19=E. |last20=Tanvir |first20=N. R. |last21=Wiersema |first21=K. |last22=Xu |first22=D. |last23=Albert |first23=L. |last24=Bayliss |first24=M. |last25=Gall |first25=C. |last26=Grove |first26=L. F. |last27=Koester |first27=B. P. |last28=Leitet |first28=E. |last29=Pursimo |first29=T. |last30=Skillen |first30=I. |title=Early Spectroscopic Identification of SN 2008D |journal=The Astrophysical Journal Letters |date=February 2009 |volume=692 |issue=2 |pages=L84-L87 |bibcode=2009ApJ...692L..84M |doi=10.1088/0004-637X/692/2/L84 |url=https://iopscience.iop.org/article/10.1088/0004-637X/692/2/L84/pdf |access-date=12 June 2025}}]]

The supernova was determined to be of Type Ibc. The velocities measured from SN2008D indicated expansion rates of more than 10,000 kilometers per second. The explosion was off-center, with gas on one side of the explosion moving outward faster than on the other. This was the first time the X-ray emission pattern of a supernova (which only lasted about five minutes) was captured at the moment of its birth. Now that it is known what X-ray pattern to look for, the next generation of X-ray satellites is expected to find hundreds of supernovae every year exactly when they explode, which will allow searches for neutrino and gravitational wave bursts that are predicted to accompany the collapse of stellar cores and the birth of neutron stars.