Beethoven Burst (GRB 991216)
Encyclopedia
GRB 991216, nicknamed the Beethoven Burst by Dr. Brad Schaefer of Yale University
Yale University
Yale University is a private, Ivy League university located in New Haven, Connecticut, United States. Founded in 1701 in the Colony of Connecticut, the university is the third-oldest institution of higher education in the United States...

, was a gamma ray burst
Gamma ray burst
Gamma-ray bursts are flashes of gamma rays associated with extremely energetic explosions that have been observed in distant galaxies. They are the most luminous electromagnetic events known to occur in the universe. Bursts can last from ten milliseconds to several minutes, although a typical...

 observed on December 16, 1999, coinciding with the 229th anniversary of Ludwig van Beethoven's birth. A gamma-ray burst is a highly luminous
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,...

).

The optical afterglow of the burst reached an apparent magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...

 of 18.7, making the Beethoven Burst one of the brightest bursts ever detected, even though it occurred about 10 billion light years
Light Years
Light Years is the seventh studio album by Australian recording artist Kylie Minogue. It was released on 25 September 2000 by Parlophone and Mushroom Records. The album's style was indicative of her return to "mainstream pop dance tunes"....

 from Earth. Frank Marshall, a 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...

 astrophysicist at the Goddard Space Flight Center
Goddard Space Flight Center
The Goddard Space Flight Center is a major NASA space research laboratory established on May 1, 1959 as NASA's first space flight center. GSFC employs approximately 10,000 civil servants and contractors, and is located approximately northeast of Washington, D.C. in Greenbelt, Maryland, USA. GSFC,...

, commented that "this was by far the brightest burst we have detected in a long time." The burst's peak flux
Flux
In the various subfields of physics, there exist two common usages of the term flux, both with rigorous mathematical frameworks.* In the study of transport phenomena , flux is defined as flow per unit area, where flow is the movement of some quantity per time...

 ranked it as the second most powerful burst that the Burst and Transient Source Experiment (BATSE) had ever detected. The analysis of the observations strengthened the theory that gamma-ray bursts are a result of a hypernova
Hypernova
Hypernova , also known as a type 1c Supernova, refers to an incredibly large star that collapses at the end of its lifespan...

, though other possible progenitors exist, such as the merger of two black holes.

Within four hours of the burst's detection, observations made by BATSE and the Rossi X-ray Timing Explorer
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...

 were able to determine the burst's position of α
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:...

 = 77.38 ± 0.04, δ
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...

 = 11.30 ± 0.05. This rapid determination allowed astronomers to conduct follow-up studies using optical and 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...

 telescopes. Other instruments which detected GRB 991216 included the Chandra X-ray Observatory
Chandra X-ray Observatory
The Chandra X-ray Observatory is a satellite launched on STS-93 by NASA on July 23, 1999. It was named in honor of Indian-American physicist Subrahmanyan Chandrasekhar who is known for determining the maximum mass for white dwarfs. "Chandra" also means "moon" or "luminous" in Sanskrit.Chandra...

, the MDM Observatory
MDM Observatory
The MDM Observatory is an optical astronomical observatory on Kitt Peak , adjacent to Kitt Peak National Observatory. It is owned and operated by the University of Michigan, Dartmouth College, Ohio State University, Columbia University, and Ohio University...

, and the Space Telescope Imaging Spectrograph
Space Telescope Imaging Spectrograph
The Space Telescope Imaging Spectrograph is a spectrograph, also with a camera mode, installed on the Hubble Space Telescope. It operated continuously from 1997 until a power supply failure in 2004. After repairs, it began operating again in 2009...

 on board the Hubble Space Telescope
Hubble Space Telescope
The Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...

. This was the first use of the Chandra X-ray Observatory
Chandra X-ray Observatory
The Chandra X-ray Observatory is a satellite launched on STS-93 by NASA on July 23, 1999. It was named in honor of Indian-American physicist Subrahmanyan Chandrasekhar who is known for determining the maximum mass for white dwarfs. "Chandra" also means "moon" or "luminous" in Sanskrit.Chandra...

for the purpose of gamma-ray burst detection.
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