Massive Star burps, then explodes Department of Physics National Tsing Hua University G.T. Chen 2007/5/1 April 4, 2007 .

Massive Star burps, Massive Star burps, then explodesthen explodes

Department of PhysicsDepartment of PhysicsNational Tsing Hua UniversityNational Tsing Hua University

G.T. ChenG.T. Chen2007/5/12007/5/1

April 4, 2007

http://spaceflightnow.com/news

SN 2006jcSN 2006jc

►R.A. : 09h 17m 20.78s R.A. : 09h 17m 20.78s ►Dec. : +41º 54' 32.7" Dec. : +41º 54' 32.7" ►Distance: ~77 M light years in UGC4904Distance: ~77 M light years in UGC4904►Constellation: Lynx (Constellation: Lynx ( 山貓山貓 ))►Type Ib supernovaType Ib supernova

Lacks hydrogen and presents non-ionized helium (He I) line at 587.6 nm and no strong silicon absorption feature near 615 nm.

SN 2006jcSN 2006jc

A color image of SN2006jc (center) taken by the Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory on Oct. 13, 2006

Swift Ultraviolet/Optical Telescope image of Supernova 2006jc in the galaxy UGC 4904 in three filters

Swift X-ray Telescope image of Supernova 2006jc

Chandra X-ray Observatory image of Supernova 2006jc

SN 2006jcSN 2006jc

►On Oct. 20, 2004 , Koichi Itagaki saw the stOn Oct. 20, 2004 , Koichi Itagaki saw the star let loose an outburst so bright that it war let loose an outburst so bright that it was initially mistaken for a supernova.as initially mistaken for a supernova.

►On Oct. 11, 2006, astronomers witnessed tOn Oct. 11, 2006, astronomers witnessed the star actually blowing itself as Supernovhe star actually blowing itself as Supernova 2006jc.a 2006jc.

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►““We have never observed a stellar We have never observed a stellar outburst and then later seen the star outburst and then later seen the star explode.” said Ryan Foley.explode.” said Ryan Foley.

► Narrow helium spectral lines showed Narrow helium spectral lines showed that the supernova's blast wave ran that the supernova's blast wave ran into a slow-moving shell of material, into a slow-moving shell of material, presumably the progenitor's outer presumably the progenitor's outer layers that were ejected just two years layers that were ejected just two years earlier. earlier.

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►Foley’s group propose that the star receFoley’s group propose that the star recently transitioned from a ntly transitioned from a Luminous Blue VaLuminous Blue Variableriable (LBV) star to a (LBV) star to a Wolf-Rayet starWolf-Rayet star. .

►Similar to the 2004 eruption, LBVs tended Similar to the 2004 eruption, LBVs tended to blow off large amounts of mass in outbto blow off large amounts of mass in outbursts so extreme that they are frequently ursts so extreme that they are frequently mistaken for supernovae. mistaken for supernovae.

►They called these events are "supernova iThey called these events are "supernova impostors." mpostors."

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►Most astronomers did not expect that a mMost astronomers did not expect that a massive star would explode so soon after a assive star would explode so soon after a major outburst, or that a Wolf-Rayet star major outburst, or that a Wolf-Rayet star would produce such a luminous eruption, would produce such a luminous eruption, so SN 2006jc represents a puzzle for theoriso SN 2006jc represents a puzzle for theorists. sts.

►““It opens up a new window on how some It opens up a new window on how some kinds of stars die.” said Alex Filippenko.kinds of stars die.” said Alex Filippenko.

ReferencesReferences

►http://spaceflightnow.com/newshttp://spaceflightnow.com/news April 4, 2007April 4, 2007►http://www.nasa.gov/centers/goddard/nhttp://www.nasa.gov/centers/goddard/n

ews/topstory/2007/supernova_imposter.ews/topstory/2007/supernova_imposter.htmlhtml

►ApJ 657:L105-L108, 2007 March 10ApJ 657:L105-L108, 2007 March 10

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