GRB 030329
Encyclopedia
GRB 030329 was a gamma-ray burst (GRB) that was detected on 29 March 2003 at 11:37 UTC. A gamma-ray burst is a highly luminous
flash associated with an explosion in a distant galaxy and producing gamma ray
s, the most energetic form of electromagnetic radiation
, and often followed by a longer-lived "afterglow" emitted at longer wavelengths (X-ray
, ultraviolet
, optical, infrared
, and radio
). GRB 030329 was the first burst whose afterglow definitively exhibited characteristics of a supernova
, confirming the existence of a relationship between the two phenomena.
at 11:37 UTC and lasted approximately 25 seconds. The burst's optical afterglow was first observed from Siding Spring Observatory
less than two hours after the burst had been detected. The X-ray afterglow was first detected by RXTE
approximately five hours after the burst. The radio afterglow was first detected by the Very Large Array
and, at the time of its discovery, was the brightest radio afterglow ever observed. The burst was located at a sky position of R.A.
= , Dec.
= and had a redshift of z = 0.1685, corresponding to a distance of 587 Mpc
.
taken of the burst's optical afterglow on 6 April 2003 showed peaks at approximately 570 nm and 470 nm. This spectrum was reproduced by combining a power-law distribution with the spectrum from SN 1998bw
. These supernova-like features continued to develop in the weeks after the initial burst. Optical observations taken at Kitt Peak National Observatory
on indicated that the burst's optical afterglow was brighter than a power-law decay would have predicted, a deviation that could have been explained by additional light from a supernova. On 10 April 2003, NASA
announced that GRB 030329 had provided the definitive link between gamma-ray bursts and supernovae. The supernova was later referred to as SN 2003dh.
Luminosity
Luminosity is a measurement of brightness.-In photometry and color imaging:In photometry, luminosity is sometimes incorrectly used to refer to luminance, which is the density of luminous intensity in a given direction. The SI unit for luminance is candela per square metre.The luminosity function...
flash associated with an explosion in a distant galaxy and producing gamma ray
Gamma ray
Gamma radiation, also known as gamma rays or hyphenated as gamma-rays and denoted as γ, is electromagnetic radiation of high frequency . Gamma rays are usually naturally produced on Earth by decay of high energy states in atomic nuclei...
s, the most energetic form of electromagnetic radiation
Electromagnetic radiation
Electromagnetic radiation is a form of energy that exhibits wave-like behavior as it travels through space...
, and often followed by a longer-lived "afterglow" emitted at longer wavelengths (X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
, ultraviolet
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
, optical, infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
, and radio
Radio waves
Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies from 300 GHz to as low as 3 kHz, and corresponding wavelengths from 1 millimeter to 100 kilometers. Like all other electromagnetic waves,...
). GRB 030329 was the first burst whose afterglow definitively exhibited characteristics of a supernova
Supernova
A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...
, confirming the existence of a relationship between the two phenomena.
Observations
GRB 030329 was one of three gamma-ray bursts detected on 29 March 2003. The other two were labeled GRB 030329a and GRB 030329b. GRB 030329 was detected by multiple instruments onboard HETEHigh Energy Transient Explorer
The High Energy Transient Explorer was an American astronomical satellite with international participation . The prime objective of HETE was to carry out the first multiwavelength study of gamma-ray bursts with UV, X-ray, and gamma-ray instruments mounted on a single, compact spacecraft...
at 11:37 UTC and lasted approximately 25 seconds. The burst's optical afterglow was first observed from Siding Spring Observatory
Siding Spring Observatory
Siding Spring Observatory near Coonabarabran, New South Wales, Australia, part of the Research School of Astronomy & Astrophysics at the Australian National University , incorporates the Anglo-Australian Telescope along with a collection of other telescopes owned by the Australian National...
less than two hours after the burst had been detected. The X-ray afterglow was first detected by RXTE
Rossi X-ray Timing Explorer
The Rossi X-ray Timing Explorer is a satellite that observes the time structure of astronomical X-ray sources. The RXTE has three instruments—the Proportional Counter Array, the High-Energy X-ray Timing Experiment , and one instrument called the All Sky Monitor...
approximately five hours after the burst. The radio afterglow was first detected by the Very Large Array
Very Large Array
The Very Large Array is a radio astronomy observatory located on the Plains of San Agustin, between the towns of Magdalena and Datil, some fifty miles west of Socorro, New Mexico, USA...
and, at the time of its discovery, was the brightest radio afterglow ever observed. The burst was located at a sky position of R.A.
Right ascension
Right ascension is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. The other coordinate is the declination.-Explanation:...
= , Dec.
Declination
In astronomy, declination is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Declination in astronomy is comparable to geographic latitude, but projected onto the celestial sphere. Declination is measured in degrees north and...
= and had a redshift of z = 0.1685, corresponding to a distance of 587 Mpc
Parsec
The parsec is a unit of length used in astronomy. It is about 3.26 light-years, or just under 31 trillion kilometres ....
.
Supernova relation
GRB 030329's proximity to Earth enabled its afterglow to be studied in great detail. A spectrumSpectroscopy
Spectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism. Later the concept was expanded greatly to comprise any interaction with radiative...
taken of the burst's optical afterglow on 6 April 2003 showed peaks at approximately 570 nm and 470 nm. This spectrum was reproduced by combining a power-law distribution with the spectrum from SN 1998bw
SN 1998bw
SN 1998bw was a rare type I/Ib gamma ray supernova detected on 26 April 1998 in the ESO 184-G82 spiral galaxy, which some astronomers believe may be an example of a collapsar. The supernova has been linked to GRB 980425, which was detected on 25 April 1998, the first time a gamma-ray burst has...
. These supernova-like features continued to develop in the weeks after the initial burst. Optical observations taken at Kitt Peak National Observatory
Kitt Peak National Observatory
The Kitt Peak National Observatory is a United States astronomical observatory located on 2,096 m Kitt Peak of the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono O'odham Nation, southwest of Tucson...
on indicated that the burst's optical afterglow was brighter than a power-law decay would have predicted, a deviation that could have been explained by additional light from a supernova. On 10 April 2003, NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
announced that GRB 030329 had provided the definitive link between gamma-ray bursts and supernovae. The supernova was later referred to as SN 2003dh.