SN 2011fe
{{Short description|Supernova in the Pinwheel Galaxy}}
{{Infobox supernova
| name = SN 2011fe{{Cite web |last=Beatty |first=Kelly |date=25 August 2011 |title=Supernova Erupts in Pinwheel Galaxy |work=Sky & Telescope |url=http://www.skyandtelescope.com/observing/highlights/128430288.html |access-date=26 August 2011 }}
| image = 300px
| caption = Supernova event on August 25, 2011
| epoch = J2000{{Cite web |last=Templeton |first=Matthew |date=24 August 2011 |title=Special Notice #250: Possible Type-Ia Supernova in M101 |publisher=American Association of Variable Star Observers |url=http://www.aavso.org/special-notice-250-possible-type-ia-supernova-m101 |access-date=26 August 2011 |archive-date=28 December 2013 |archive-url=https://web.archive.org/web/20131228060358/http://www.aavso.org/special-notice-250-possible-type-ia-supernova-m101 |url-status=dead }}
| type = Ia
| SNRtype =
| host = Pinwheel Galaxy (M101)
| constellation = Ursa Major, Big Dipper
| gal =
| iauc =
| mag_v = 9.9[https://www.rochesterastronomy.org/sn2011/snmag.html List of supernovae sorted by Magnitude for 2011] (David Bishop)
| distance = 21 Mly
| progenitor =
| progenitor_type =
| b-v =
| notes =
}}
SN 2011fe, initially designated PTF 11kly, was a Type Ia supernova discovered by the Palomar Transient Factory (PTF) survey on 24 August 2011 during an automated review of images of the Messier 101 from the nights of 22 and 23 August 2011. It was located in Messier 101, the Pinwheel Galaxy, 21 million light years from Earth.{{cite journal
|last=Shappee
|first=Benjamin
|author2=Stanek, Kris
|title=A New Cepheid Distance to the Giant Spiral M101 Based on Image Subtraction of Hubble Space Telescope/Advanced Camera for Surveys Observations
|journal=Astrophysical Journal
|date=June 2011
|volume=733
|issue=2
|pages=124
|doi=10.1088/0004-637X/733/2/124
|bibcode = 2011ApJ...733..124S
|arxiv = 1012.3747
|s2cid=121792901
}} It was observed by the PTF survey very near the beginning of its supernova event, when it was approximately 1 million times too dim to be visible to the naked eye. It is the youngest Type Ia ever discovered.{{Cite web|url=http://newscenter.lbl.gov/feature-stories/2011/08/25/supernova/|title=Berkeley Scientists Discover an "Instant Cosmic Classic" Supernova|date=25 August 2011}} About 13 September 2011, it reached its maximum brightness of apparent magnitude +9.9{{cite web |title=Supernova 2011fe in M101|author=Hartmut Frommert|author2=Christine Kronberg|name-list-style=amp |url=http://messier.seds.org/more/m101_sn2011fe.html |date=15 Sep 2011 |access-date=17 Sep 2011}} which equals an absolute magnitude of about -19, equal to 2.5 billion Suns. At +10 apparent magnitude around 5 September, SN 2011fe was visible in small telescopes. As of 30 September the supernova was at +11 apparent magnitude in the early evening sky after sunset above the northwest horizon. It had dropped to +13.7 as of 26 November 2011.{{Cite web|url=http://ooruri.kusastro.kyoto-u.ac.jp/mailarchive/vsnet-recent-sn/2676|title=[vsnet-recent-sn 2676] SN2011ht recent (Cont'd)}}
Discovery
File:Supernova SN2011fe in M101 (noao-m101sn2011fe).tiff
The Palomar Transient Factory is an automated telescopic survey that scans the sky for transient and variable astronomical events. Information is fed to the National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Lab, which computes the information to identify new star events. After the initial observation of the SN 2011fe event, telescopes were used in the Canary Islands (Spain) to identify the emission spectrum of light emitted at various stages of the event. Following this, the Hubble Space Telescope, the Lick Observatory in California, and the Keck Observatory in Hawaii were used to observe the event in greater detail.
File:SN2011feLightCurve.png. The inset plot shows the time around peak brightness with an expanded scale. Adapted from Zhang et al. (2016){{cite journal |last1=Zhang |first1=Kaicheng |last2=Wang |first2=Xiaofeng |last3=Zhang |first3=JuJia |last4=Zhang |first4=Tianmeng |last5=Ganeshalingam |first5=Mohan |last6=Li |first6=Weidong |last7=Filippenko |first7=Alexei V. |last8=Zhao |first8=Xulin |last9=Zheng |first9=Weikang |last10=Bai |first10=Jinming |last11=Chen |first11=Jia |last12=Chen |first12=Juncheng |last13=Huang |first13=Fang |last14=Mo |first14=Jun |last15=Rui |first15=Liming |last16=Song |first16=Hao |last17=Sai |first17=Hanna |last18=Li |first18=Wenxiong |last19=Wang |first19=Lifan |last20=Wu |first20=Chao |title=Optical Observations of the Type Ia Supernova SN 2011fe in M101 for Nearly 500 Days |journal=The Astrophysical Journal |date=March 2016 |volume=820 |issue=1 |page=67 |bibcode=2016ApJ...820...67Z |doi=10.3847/0004-637X/820/1/67 |doi-access=free |arxiv=1602.02951 }} and Tucker et al. (2022){{cite journal |last1=Tucker |first1=M. A. |last2=Shappee |first2=B. J. |last3=Kochanek |first3=C. S. |last4=Stanek |first4=K. Z. |last5=Ashall |first5=C. |last6=Anand |first6=G. S. |last7=Garnavich |first7=P. |title=The whisper of a whimper of a bang: 2400 d of the Type Ia SN 2011fe reveals the decay of 55Fe |journal=Monthly Notices of the Royal Astronomical Society |date=December 2022 |volume=517 |issue=3 |pages=4119–4131 |bibcode=2022MNRAS.517.4119T |doi=10.1093/mnras/stac2873 |doi-access=free |url=https://ui.adsabs.harvard.edu/link_gateway/2022MNRAS.517.4119T/PUB_PDF |access-date=15 June 2025|arxiv=2111.01144 }}]]
Although SN 2011fe was initially very faint, it brightened rapidly. On the day it was first imaged, 24 August 2011, it was 1 million times too dim to be visible to the unaided eye. One day later, it was 10 thousand times too dim. The next day it was 6 times brighter than that. On 25 August, the EVLA radio telescope failed to detect radio emissions from SN 2011fe. While such emissions are common for other types of supernovae, they have never been observed for Type Ia's.http://www.astronomerstelegram.org/?read=3597 EVLA Radio Observations of SN 2011fe
Two possible candidates were proposed for the precursor system;{{cite web |title=Further Analysis of the archival HST images of PTF11kly in M101 |url=http://www.astronomerstelegram.org/?read=3585 |author=Weidong Li |display-authors=etal |publisher=The Astronomer's Telegram |date=25 August 2011 |access-date=25 August 2011}} however, subsequent analysis appears to rule them out.
Importance of Type Ia supernovae and SN 2011fe
Type Ia supernova events occur when a white dwarf star accretes enough additional matter to exceed the Chandrasekhar limit and collapses, triggering runaway fusion and a supernova explosion. Because this collapse happens at a consistent mass, the resulting explosions have very uniform characteristics, and are used as "standard candles" to measure the distance to their host galaxies. The exact brightness and behavior of a Type Ia supernova depends on the metallicity of its parent star (the fraction of the star composed of elements heavier than hydrogen and helium before its evolution into a white dwarf). Because the SN 2011fe event was detected so early, astronomers can gain a more accurate measurement of its initial composition and of its evolution during the supernova explosion, and so refine their models of Type Ia supernova events, resulting in more precise distance estimates for other Type Ia supernova observations.{{ref|naturenews|1}}
Type Ia supernova standard candles may help provide evidence to support the hypothesis of dark energy and the accelerating expansion of the universe.{{cite journal | first=S.| last=Perlmutter | journal=Astrophysical Journal | volume=517 | issue=2| pages=565–86| date=1999 | title=Measurements of Omega and Lambda from 42 high redshift supernovae | doi=10.1086/307221 | author2=Aldering, G. | arxiv=astro-ph/9812133 | bibcode=1999ApJ...517..565P | display-authors=1| hdl=2445/67862 | s2cid=118910636 | hdl-access=free }} A better understanding of Type Ia supernova behavior may in turn allow theoretical models of dark energy to be improved.
References
{{Reflist}}
External links
- {{note|naturenews}}[http://blogs.nature.com/news/2011/08/bright_supernova_one_of_the_ne.html Nature: Nearby supernova may illuminate dark energy puzzle] {{Webarchive|url=https://web.archive.org/web/20111011120651/http://blogs.nature.com/news/2011/08/bright_supernova_one_of_the_ne.html |date=2011-10-11 }}
- [http://newscenter.lbl.gov/feature-stories/2011/08/25/supernova/ Berkeley Scientists Discover an “Instant Cosmic Classic” Supernova]
- [http://content.usatoday.com/communities/sciencefair/post/2011/08/nearby-supernova-blooms-into-view/1 USA Today: Nearby supernova blooms into view]
- [https://www.theregister.co.uk/2011/08/26/type_1a_ptf_11kly_supernova_discovered/ Supercomputer and superboffins spot rare baby supernova]
- [https://sne.space/sne/SN2011fe/ Light curves and spectra] {{Webarchive|url=https://web.archive.org/web/20171022142903/https://sne.space/sne/SN2011fe/ |date=2017-10-22 }} on the [https://sne.space Open Supernova Catalog] {{Webarchive|url=https://web.archive.org/web/20160303230459/https://sne.space/ |date=2016-03-03 }}
- [https://web.archive.org/web/20111016020730/http://virtualtelescope.bellatrixobservatory.org/m101sn.html SN 2011fe animations]
- [http://www.rochesterastronomy.org/sn2011/sn2011fe.html Rochester Academy of Sciences index page on SN 2011fe]
- [https://web.archive.org/web/20140202180350/http://www.factsall.com/supernova-in-our-neighborhood/ Supernova SN2001fe]
{{Supernovae}}
{{2011 in space}}