GRB 030329 was a

gamma-ray burst In gamma-ray astronomy, gamma-ray bursts (GRBs) are extremely energetic events occurring in distant Galaxy, galaxies which represent the brightest and most powerful class of explosion in the universe. These extreme Electromagnetic radiation, ele ...

(GRB) that was detected on 29 March 2003 at 11:37

UTC Coordinated Universal Time (UTC) is the primary time standard globally used to regulate clocks and time. It establishes a reference for the current time, forming the basis for civil time and time zones. UTC facilitates international communica ...

. A gamma-ray burst is a highly luminous flash associated with an explosion in a distant galaxy and producing

gamma ray A gamma ray, also known as gamma radiation (symbol ), is a penetrating form of electromagnetic radiation arising from high energy interactions like the radioactive decay of atomic nuclei or astronomical events like solar flares. It consists o ...

s, the most energetic form of

electromagnetic radiation In physics, electromagnetic radiation (EMR) is a self-propagating wave of the electromagnetic field that carries momentum and radiant energy through space. It encompasses a broad spectrum, classified by frequency or its inverse, wavelength ...

, and often followed by a longer-lived "afterglow" emitted at longer wavelengths (

X-ray An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

ultraviolet Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of ...

optical Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultravio ...

infrared Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those ...

, and

radio Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connec ...

). GRB 030329 was the first burst whose afterglow definitively exhibited characteristics of a

supernova A supernova (: supernovae or supernovas) is a powerful and luminous explosion of a star. A supernova occurs during the last stellar evolution, evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion ...

, 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 HETE at 11:37

and lasted approximately 25 seconds. The burst's optical afterglow was first observed from

Siding Spring Observatory Siding Spring Observatory near Coonabarabran, New South Wales, Australia, part of the Research School of Astronomy & Astrophysics (RSAA) at the Australian National University (ANU), incorporates the Anglo-Australian Telescope along with a coll ...

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 The Karl G. Jansky Very Large Array (VLA) is a centimeter-wavelength radio astronomy observatory in the southwestern United States built in the 1970s. It lies in central New Mexico on the Plains of San Agustin, between the towns of Magdalena, Ne ...

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.

Supernova relation

GRB 030329's proximity to Earth enabled its afterglow to be studied in great detail. A

spectrum A spectrum (: spectra or spectrums) is a set of related ideas, objects, or properties whose features overlap such that they blend to form a continuum. The word ''spectrum'' was first used scientifically in optics to describe the rainbow of co ...

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 In statistics, a power law is a functional relationship between two quantities, where a relative change in one quantity results in a relative change in the other quantity proportional to the change raised to a constant exponent: one quantity var ...

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 The Kitt Peak National Observatory (KPNO) is a United States astronomy, astronomical observatory located on Kitt Peak of the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono Oʼodham Nation, west-southwest of Tucson, Arizona. With ...

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 The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

announced that GRB 030329 had provided the definitive link between gamma-ray bursts and supernovae. The supernova was later referred to as SN 2003dh.

Notes

{{reflist 030329 20030329 March 2003 Leo (constellation)