SN 2003fg, nicknamed the Champagne Supernova, was an unusual
Type Ia
A Type Ia supernova (read: "type one-A") is a type of supernova that occurs in binary systems (two stars orbiting one another) in which one of the stars is a white dwarf. The other star can be anything from a giant star to an even smaller whi ...
supernova. It was discovered in 2003, with the
Canada-France-Hawaii Telescope and the
Keck Telescope, both on
Mauna Kea in
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state ...
, and announced by researchers at the
University of Toronto
The University of Toronto (UToronto or U of T) is a public university, public research university in Toronto, Ontario, Canada, located on the grounds that surround Queen's Park (Toronto), Queen's Park. It was founded by royal charter in 1827 ...
.
The supernova occurred in a galaxy some 4 billion light-years from Earth. It was nicknamed after the 1995 song "
Champagne Supernova
"Champagne Supernova" is a song by English rock band Oasis, written by Noel Gallagher. It is the closing track on the band's second studio album, ''(What's the Story) Morning Glory?'' (1995), and was released as the sixth and final single from ...
" by English
rock
Rock most often refers to:
* Rock (geology), a naturally occurring solid aggregate of minerals or mineraloids
* Rock music, a genre of popular music
Rock or Rocks may also refer to:
Places United Kingdom
* Rock, Caerphilly, a location in Wales ...
band
Oasis.
It was unusual because of the mass of its progenitor. According to the current understanding,
white dwarf
A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes ...
stars explode as
Type Ia supernova
A Type Ia supernova (read: "type one-A") is a type of supernova that occurs in binary systems (two stars orbiting one another) in which one of the stars is a white dwarf. The other star can be anything from a giant star to an even smaller white ...
s when their mass approaches 1.4
solar masses, termed the
Chandrasekhar limit
The Chandrasekhar limit () is the maximum mass of a stable white dwarf star. The currently accepted value of the Chandrasekhar limit is about ().
White dwarfs resist gravitational collapse primarily through electron degeneracy pressure, compa ...
. The mass added to the star is believed to be donated by a companion star, either from the companion's
stellar wind or the overflow of its
Roche lobe
In astronomy, the Roche lobe is the region around a star in a binary system within which orbiting material is gravitationally bound to that star. It is an approximately teardrop-shaped region bounded by a critical gravitational equipotential ...
as it evolves.
However, the progenitor of SN 2003fg reached two
solar masses before exploding. The primary mechanism invoked to explain how a white dwarf can exceed the Chandrasekhar mass is unusually rapid
rotation; the added support effectively increases the critical mass. An alternative explanation is that the explosion resulted from the merger of two white dwarfs. The evidence indicating a higher than normal mass comes from the
light curve
In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular frequ ...
and spectra of the supernova—while it was particularly overluminous, the kinetic energies measured from the spectra appeared smaller than usual. One proposed explanation is that more of the total kinetic energy budget was expended climbing out of the deeper than usual potential well.
This is important because the brightness of
type Ia supernova
A Type Ia supernova (read: "type one-A") is a type of supernova that occurs in binary systems (two stars orbiting one another) in which one of the stars is a white dwarf. The other star can be anything from a giant star to an even smaller white ...
e was thought to be essentially uniform, making them useful "
standard candle
The cosmic distance ladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to celestial objects. A ''direct'' distance measurement of an astronomical object is possible o ...
s" in measuring distances in the universe. Such an aberrant type Ia supernova could throw distances and other scientific work into doubt; however, the light curve characteristics of SN 2003fg were such that it would never have been mistaken for an ordinary high-redshift Type Ia supernova.
References
External links
Light curves and spectrumon th
Open Supernova Catalog*
'Champagne supernova' challenges understanding of how supernovae work - University of TorontoCosmos Magazine - ''"Rebellious supernova confronts dark energy"''Astronomy: Champagne supernova - ''Nature''
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{{supernovae
Supernovae
Astronomical objects discovered in 2003
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