 The sudden appearance of the transient "mystery object"SCP 06F6 inHubble Space Telescope's field of view. The lower image quadrant represents a zoomed in view. | |
| Event type | Supernova  |
|---|---|
| SNIc, SLSNIc | |
| Constellation | Boötes |
| Other designations | SCP 06F6 |
SCP 06F6 is (or was) anastronomical object of unknown type, discovered on 21 February 2006 in the constellationBoötes[1]during a survey ofgalaxy cluster CL 1432.5+3332.8 with theHubble Space Telescope'sAdvanced Camera for Surveys Wide Field Channel.[2]
According to research authored by Kyle Barbary of theSupernova Cosmology Project, the object brightened over a period of roughly 100 days, reaching a peak intensity ofmagnitude 21; it then faded over a similar period.[2]
Barbary and colleagues report that thespectrum of light emitted from the object does not match knownsupernova types, and is dissimilar to any knownphenomenon in theSloan Digital Sky Survey database. The light in the blue region shows broad line features, while the red region shows continuous emission.[3] The spectrum shows a handful of spectral lines, but when astronomers try to trace any one of them to an element the other lines fail to match up with any other known elements.[2]
Because of its uncommon spectrum, the team was not able to determine the distance to the object using standardredshift techniques; it is not even known whether the object is within or outside theMilky Way.[1] Furthermore, no Milky Way star or external galaxy has been detected at this location,[2] meaning any source is very faint.
The European X-ray satelliteXMM Newton made an observation in early August 2006 which appears to show an X-ray glow around SCP 06F6,[4] two orders of magnitude more luminous than that of supernovae.[5]
Observations from thePalomar Transient Factory, reported in 2009, indicate a redshiftz = 1.189 and a peak magnitude of −23.5 absolute (comparable toSN2005ap), making SCP 06F6 one of the most luminous transient phenomena known as of that date.[6]
Supernovae reach their maximum brightness in only 20 days, and then take much longer to fade away. Researchers had initially conjectured that SCP 06F6 might be an extremely remote supernova; relativistic time dilation might have caused a 20-day event to stretch out over a period of 100 days. But this explanation now seems unlikely.[1] Other conjectures that have been advanced involve a collision between awhite dwarf and anasteroid, or the collision of a white dwarf with ablack hole.[7]
An analysis by a team from theUniversity of Warwick (Boris Gänsicke et al.) suggests that the light spectrum is "consistent with emission from a cool,carbon-rich atmosphere at aredshift of z~0.14",[5] possibly representing the core collapse and explosion of acarbon star.[4] Gänsicke's group concurs with Barbary and colleagues that SCP 06F6 may represent "a new class" ofcelestial object.[2][5]
The analysis of Israeli astronomers ofTechnion suggests four alternative explanations for SCP 06F6, in plausibility order: the tidal destruction of a carbon-oxygenwhite dwarf by anintermediate-mass black hole, atype Iasupernova exploding inside the dense stellar wind of acarbon star, anasteroid that was swallowed up by a white dwarf or, least likely, acore-collapse supernova.[8]
Observations in 2009 indicate that it may be apair-instability supernova.[6]
The event was similar toSN 2005ap, and other unusually bright supernova suggesting that it was a new type of supernova.[9]
