KELT-2Ab is an
extrasolar planet
An exoplanet or extrasolar planet is a planet outside the Solar System. The first confirmed detection of an exoplanet was in 1992 around a pulsar, and the first detection around a main-sequence star was in 1995. A different planet, first detect ...
that orbits the
star
A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sk ...
KELT-2A approximately 440
light-year
A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by the International Astr ...
s away in the
constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object.
The first constellati ...
of
Auriga
Auriga is a constellation in the northern celestial hemisphere. It is one of the 88 modern constellations; it was among the 48 constellations listed by the 2nd-century astronomer Ptolemy. Its name is Latin for '(the) charioteer', associating i ...
.
It was discovered by the
KELT-North survey via the
transit
Transit may refer to:
Arts and entertainment Film
* ''Transit'' (1980 film), a 1980 Israeli film
* ''Transit'' (1986 film), a Canadian short film
* ''Transit'' (2005 film), a film produced by MTV and Staying-Alive about four people in countrie ...
method - so both its mass and radius are known quite precisely - in a paper led by
Thomas Beatty. As of its discovery KELT-2Ab is the fifth-brightest transiting
Hot Jupiter
Hot Jupiters (sometimes called hot Saturns) are a class of gas giant exoplanets that are inferred to be physically similar to Jupiter (i.e. Jupiter analogue, Jupiter analogues) but that have very short orbital periods (). The close proximity to t ...
known that has a well constrained mass. This makes the KELT-2A system a promising target for future space- and ground-based follow-up observations to learn about the planet's atmosphere.
Water vapour was detected in planetary atmosphere in 2018.
The star KELT-2A is a member of the common-proper-motion
binary star system
A binary star or binary star system is a Star system, system of two stars that are gravity, gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved ...
KELT-2 (HD 42176). KELT-2B is an early
K dwarf approximately 295
astronomical unit
The astronomical unit (symbol: au or AU) is a unit of length defined to be exactly equal to . Historically, the astronomical unit was conceived as the average Earth-Sun distance (the average of Earth's aphelion and perihelion), before its m ...
s away.
See also
*
KELT KELT may refer to:
*A Salmonid that has spawned at least once and did not die afterwards
*An alternative spelling of Celt
* KELT (FM), call letters of an FM radio station located in Encinal, Texas
* KELT, the former call letters of an FM radio stat ...
*
KELT-9b
*
KELT-1
*
KELT-10
*
KELT-11b
References
External links
KELT-North survey website
*
KELT-2Ab discovery lightcurve, with music
{{2012 in space
Auriga
Hot Jupiters
Transiting exoplanets
Exoplanets discovered in 2012
Giant planets
Exoplanets discovered by KELT