A collapsar is a fast-rotating Wolf-Rayet star with a massive (greater than 30 solar masses) core, which collapses to form a large, rotating black hole, drawing in the surrounding envelope of stellar matter at relativistic speeds with a Lorentz factor of around 150, making collapsars the fastest celestial objects known. They may be considered to be "failed" Type Ib supernovae. This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... In astronomy, the solar mass is a unit of mass used to express the mass of stars and larger objects such as galaxies. ... A black hole is a concentration of mass great enough that the force of gravity prevents anything past its event horizon from escaping it except through quantum tunnelling behaviour (known as Hawking Radiation). ... For a non-technical introduction to the topic, please see Introduction to Special relativity. ... It has been suggested that Lorentz term be merged into this article or section. ... Multiwavelength X-ray image of the remnant of Keplers Supernova, SN 1604. ...

It is believed that collapsars are the cause of long (> 2 seconds) gamma-ray bursts, since powerful energy jets would be created along the rotation axis of the black hole, creating a burst of high-energy radiation to an observer whose line of sight is along the jet. In astronomy, gamma-ray bursts (GRBs) are flashes of gamma rays that last from seconds to hours, the longer ones being followed by several days of X-ray afterglow. ... A black hole is a concentration of mass great enough that the force of gravity prevents anything past its event horizon from escaping it except through quantum tunnelling behaviour (known as Hawking Radiation). ...

A possible example of a collapsar is the supernova Sn1998bw, which was associated with the gamma-ray burst GRB980425. This was classified as a type Ic supernova due to its unusual spectral properties in the radio spectrum, indicating the presence of relativistic matter. However, it should be noted that Sn1998bw was an unusual supernova, and that GRB980425 was an unusual gamma-ray burst. Multiwavelength X-ray image of the remnant of Keplers Supernova, SN 1604. ... In astronomy, gamma-ray bursts (GRBs) are flashes of gamma rays that last from seconds to hours, the longer ones being followed by several days of X-ray afterglow. ... Multiwavelength X-ray image of the remnant of Keplers Supernova, SN 1604. ... Albert Einsteins theory of relativity is a set of two theories in physics: special relativity and general relativity. ...

See also

• Hypernova
• Gamma-ray burst
• Black Hole
• Wolf-Rayet Star

A hypernova is a theoretical type of supernova produced when an exceptionally large star collapses at the end of its lifespan. ... In astronomy, gamma-ray bursts (GRBs) are flashes of gamma rays that last from seconds to hours, the longer ones being followed by several days of X-ray afterglow. ... A black hole is a concentration of mass great enough that the force of gravity prevents anything past its event horizon from escaping it except through quantum tunnelling behaviour (known as Hawking Radiation). ... Artists impression of a Wolf-Rayet star Wolf-Rayet stars (often referred to as WR stars) are evolved, hot, massive stars which have very strong stellar winds. ...

References

• Stanford E. Woosley "Gamma-ray bursts from stellar mass accretion disks around black holes" Astrophysical Journal, Vol 405, Pages 273-277, March 1993.
• Tsvi Piran "The Physics of Gamma-Ray Bursts" Reviews of Modern Physics, Vol 76, October 2004