Possible Causes
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. Other conjectures that have been advanced involve a collision between a white dwarf and an asteroid, or the collision of a white dwarf with a black hole.
An analysis by a team from the University of Warwick (Boris Gänsicke et al.) suggests that the light spectrum is "consistent with emission from a cool, carbon-rich atmosphere at a redshift of z~0.14", possibly representing the core collapse and explosion of a carbon star. Gänsicke's group concurs with Barbary et al. that SCP 06F6 may represent "a new class" of celestial object.
The analysis of Israeli astronomers of Technion, suggest four alternative explanations for SCP 06F6, in plausibility order: the tidal destruction of a CO white dwarf by an intermediate-mass black hole, a type Ia supernova exploding inside the dense stellar wind of a carbon star, an asteroid that was swallowed up by a white dwarf or, least likely, a core-collapse supernova.
Observations in 2009 indicate that it may be a pair-instability supernova.
The event was similar to SN 2005ap, and other unusually bright supernova suggesting that it was a new type of supernova.
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