SN 2006gy
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![]() SN 2006gy and the core of its home galaxy, NGC 1260, viewed in x-ray light from the Chandra X-ray Observatory. The NGC 1260 galactic core is on the lower left and SN 2006gy is on the upper right. | ||
Observation
data (Epoch J2000) | ||
---|---|---|
Supernova type | N/A | |
Remnant type | N/A | |
Host Galaxy | NGC 1260 | |
Constellation | Perseus | |
Right ascension | 03h 17m 27.10s[1] | |
Declination | +41º 24' 19.50"[1] | |
Galactic coordinates |
N/A | |
Discovery Date | 18 September 2006 N/A | |
Peak magnitude (V) | N/A | |
Physical characteristics | ||
Progenitor | N/A | |
Progenitor type | N/A | |
Colour (B-V) | N/A | |
Notable features | N/A |
SN 2006gy was an extremely energetic supernova that was discovered
around September 18, 2006. It was first observed by R.
Quimby and P. Mondol,[1][2] and
then studied by several teams of astronomers using facilities
that included the Chandra, Lick, and Keck Observatories.[3][4] On May 7, 2007, NASA and several of the astronomers
announced the first detailed analyses of the supernova, describing it as the
"brightest stellar explosion ever
recorded".[5]
Contents |
[edit] Characteristics
SN 2006gy occurred in a distant galaxy (NGC 1260), approximately 238 million light years (72 megaparsecs) away. Therefore, due to the time it took light from the supernova to reach Earth, the event occurred about 238 million years ago. Preliminary indications are that it was an unusually high-energy supernova of a very large star, around 150 solar masses, possibly of a type referred to as a pair instability supernova. The kinetic energy released by the explosion has been estimated at 1052 ergs [1] making it ten times more powerful than the typical supernova explosion which produces 1051 ergs of energy. Because SN 2006gy has lines of hydrogen, it is classified as a type II supernova although the extreme brightness indicates that it is different from the typical type II supernova.
The supernova's light brightened for about 70 days after discovery, until roughly the beginning of December 2006, and has been slowly decreasing since then. As of early May, 2007, its luminosity is now roughly comparable to the peak luminosity of the prior most luminous observed supernovae.[4]

A pair instability supernova can only happen in stars that are very massive—having a range of around 130 to 250 solar masses. The massive star's core can produce extremely high energy gamma rays which have a greater energy than the rest mass of the electron. These gamma rays interact with electromagnetic fields of the atomic nuclei in the star, and produce particle and anti-particle pairs of electrons and positrons. The production of these particles causes some of the energy of the gamma rays to be absorbed into the matter of the star heating the interior of the star, this causes more high energy gamma rays to be produced causing more of the energy to be absorbed. This creates a runaway reaction that eventually causes the star to be blown apart. The explosion blows the star completely apart without leaving a black hole remnant behind.[6] Unlike the usual mechanism for producing type II supernova, there is no collapse phase of the star.
Although the SN 2006gy supernova is intrinsically about ten times as luminous than SN 1987A, which was bright enough to be seen by the naked eye, SN 2006gy was more than 1,400 times as far away as SN 1987A, and too far away to be seen without a telescope.[7]

[edit] Similarity to Eta Carinæ
Eta Carinæ (η Carinæ or η Car) is a highly luminous hypergiant star located approximately 7,500 light years from Earth in the Milky Way galaxy. Since Eta Carinæ is 32,000 times closer than SN2006gy, the light from it will be almost a billion-fold brighter. It is estimated to be similar in size to the star which became SN2006gy. Dave Pooley, one of the discoverers of SN2006gy, says that if Eta Carinæ exploded in a similar fashion, it would be bright enough that one could read by its light here on Earth nights, and would even be visible during the day time. SN2006gy's Apparent magnitude (m) is 15,[1] so a similar event at Eta Carinæ will have an m of about -7.5. According to astrophysicist Mario Livio, this could happen at any time, but the risk to life on Earth would be low.[8]
[edit] References
- ^ a b c d List of Supernovae. Retrieved on 2007-05-08.
- ^ IAU Circular No. 8754, accessed May 8, 2007
- ^ SN 2006gy: An extremely luminous supernova in the galaxy NGC 1260 Ofek et al., Accessed May 8 2007, arxiv.org
- ^ a b SN 2006GY: Discovery of the most luminous supernova ever recorded, powered by the death of an extremely massive star like Eta Carinae, Smith et al., accessed May 7, 2007
- ^ NASA's Chandra Sees Brightest Supernova Ever, NASA Press Release on the Discovery, May 7, 2007
- ^ Pair Instability Supernovae and Hypernovae, Nicolay J. Hammer, 2003, accessed May 7, 2007
- ^ Universe Today:Chandra Sees the Brightest Supernova, accessed May, 7, 2007
- ^ Megastar explodes in brightest supernova ever seen (English). Reuters (2007). Retrieved on 2007-05-07.
[edit] External links
- Astronomy Picture of the Day 10 May 2007
- NASA's Chandra Sees Brightest Supernova Ever
- Workshop on First Stars III website (upcoming conference, links to prior papers)
- Giant exploding star outshines previous supernovas (CNN.com)
- Space.com article on SN 2006gy.
- Star dies in brightest supernova, BBC, Tuesday, 8 May 2007, 03:35 GMT
- Supernova may offer new view of early universe
- Lick Observatory Laser Guide Star Adaptive Optics
- PAIRITEL (telescope) website