GRB 080319B
| File:218810main grb 20080320 HI.jpg The extremely luminous afterglow of GRB 080319B was imaged by Swift's X-ray Telescope (left) and Optical/Ultraviolet Telescope (right). This was by far the brightest gamma-ray burst afterglow ever seen. | |
| Event type | Gamma-ray burst  |
|---|---|
| Unknown | |
| Date | Swift Burst Alert Telescope (BAT) March 19, 2008 |
| Constellation | Boötes |
| Right ascension | 14h 31m 40.98s [1] |
| Declination | +36° 18' 8.8 |
| Epoch | J2000 |
| Distance | 7.5 gigalight-years (2.3 gigaparsecs) z=0.937 |
| Redshift | 0.94 |
| Remnant | Unknown |
| Progenitor | Unknown |
| Progenitor type | Unknown |
| Colour (B-V) | Unknown |
| Peak apparent magnitude | 5.8 |
| Other designations | GRB 080319B |
 Related media on Commons | |
GRB 080319B was a remarkable gamma-ray burst (GRB) detected by the Swift satellite at 06:12 UTC on March 19, 2008. The burst set a new record for the farthest object that could be seen with the naked eye,[2] it had a peak apparent magnitude of 5.8 and remained theoretically visible to human eyes for approximately 30 seconds.[3] The magnitude was brighter than 9.0 for some 60 seconds.[4]
Overview
The GRB's redshift was measured to be 0.937[5], which means that the explosion occurred about 7.5 billion (7.5×109) years ago, and it took the light that long to reach the Earth. This is roughly half the time since the Big Bang.[2] The first scientific paper submitted[6] on the event, suggested that the GRB could have easily been seen to a redshift of 16 (essentially to the time in the universe when stars were just being formed, well into the age of reionization) from a sub-meter sized telescope equipped with near-infrared filters.
The afterglow of the burst set a new record for the "most intrinsically bright object ever observed by humans in the universe",[2] 2.5 million times brighter than the brightest supernova to date, SN 2005ap.[7]
Evidence suggests that the afterglow was particularly bright due to the gamma jet focusing exactly at the line of sight to Earth. This allowed an unprecedented examination of the jet structure, which appears to have consisted of a narrowly focused cone and a secondary wider one. If this is the norm for GRB jets, it follows that most GRB detections only capture the fainter wide cone, which means that most distant GRBs are too faint to detect with current telescopes. This would imply that GRBs are a far more common phenomenon than so far assumed.[8]
A record for the number of observed bursts with the same satellite on one day, four, was also set. This burst was named with the suffix B since it was the second burst detected that day. In fact, there were 5 GRBs detected in a 24 hour period, including GRB 080320[9].
Until this gamma-ray burst event, the Triangulum Galaxy, at a distance of about 2.9 million light years, was the most distant object visible to the naked eye. The galaxy remains the most distant permanent object viewable without aid.[2]
It was soon suggested that this spectacle be named the Clarke Event[10], as it occurred just hours after the death of noted science fiction author Arthur C. Clarke was announced.
The plot below shows the brightness in both the optical and at higher energy for the event. The first optical exposure started about 2 seconds before the source was first observed by the SWIFT telescope and lasted for 10 seconds. The emission in both curves then peaks at around 60 seconds before a long exponential decay.
See also
References
- ^ "Gamma Ray Burst Coordinates Network". NASA. March 19, 2008. Retrieved 2008-03-21.
- ^ a b c d "NASA Satellite Detects Naked-Eye Explosion Halfway Across Universe". NASA. March 21, 2008. Retrieved 2008-03-21.
- ^ "Pi of the Sky observation of GRB080319B the brightest ever gamma-ray burst". Pi of the Sky. March 21, 2008. Retrieved 2008-03-21.
- ^ "GRB 080319B light curve". vo.astronet.ru. April 1, 2008. Retrieved 2008-04-05.
- ^ "VLT/UVES redshift of GRB 080319B". March 19, 2008. Retrieved 2008-03-25.
- ^ J. S. Bloom (March 25, 2008). "Observations of the Naked-Eye GRB 080319B: Implications of Nature's Brightest Explosion". arxiv.org. Retrieved 2008-03-25.
- ^ "Universe's most powerful blast visible to the naked eye". NewScientist. March 21, 2008. Retrieved 2008-03-21.
- ^ "Brightest gamma-ray burst was aimed at Earth". New Scientist. September 10, 2008. Retrieved 2008-09-10.
{{cite web}}: Italic or bold markup not allowed in:|publisher=(help) - ^ "Swift Burst Ground-Analysis Information". GCN. March 21, 2008. Retrieved 2008-03-25.
- ^ "Why not the Clarke Event?". EarthSky Blogs. March 21, 2008. Retrieved 2008-03-24.
Citations
- Bloom, Joshua S. (March 25, 2008). "Observations of the Naked-Eye GRB 080319B: Implications of Nature's Brightest Explosion". Astrophysical Journal. arxiv.org. Retrieved 2008-03-25.
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- Racusin, Judith L. (2008). "Broadband observations of the naked-eye γ-ray burst GRB 080319B". Nature. 455 (7210): 183–188. doi:10.1038/nature07270.
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