WASP-2b
Encyclopedia
WASP-2b is an extrasolar planet
orbiting the star
WASP-2
located about 470 light years away in the constellation
of Delphinus
. It was discovered via the transit method
, and then follow up measurements using the radial velocity method confirmed that WASP-2b was a planet. The planet's mass and radius indicate that it is a gas giant
with a similar bulk composition to Jupiter
. Unlike Jupiter, but similar to many other planets detected around other stars, WASP-2b is located very close to its star, and belongs to the class of planets known as hot Jupiter
s. A 2008 study concluded that the WASP-2b system (among others) is a binary star
system allowing even more accurate determination of stellar and planetary parameters.
Extrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...
orbiting the star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
WASP-2
WASP-2
WASP-2 is a magnitude 12 orange dwarf star located about 469 light-years away in the Delphinus constellation.-Planetary system:This star has one extrasolar planet WASP-2b, detected by the SuperWASP project in 2006.-Binary star:...
located about 470 light years away in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
of Delphinus
Delphinus
Delphinus is a constellation in the northern sky, close to the celestial equator. Its name is Latin for dolphin. Delphinus was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains among the 88 modern constellations recognized by the International Astronomical...
. It was discovered via the transit method
Methods of detecting extrasolar planets
Any planet is an extremely faint light source compared to its parent star. In addition to the intrinsic difficulty of detecting such a faint light source, the light from the parent star causes a glare that washes it out...
, and then follow up measurements using the radial velocity method confirmed that WASP-2b was a planet. The planet's mass and radius indicate that it is a gas giant
Gas giant
A gas giant is a large planet that is not primarily composed of rock or other solid matter. There are four gas giants in the Solar System: Jupiter, Saturn, Uranus, and Neptune...
with a similar bulk composition to Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
. Unlike Jupiter, but similar to many other planets detected around other stars, WASP-2b is located very close to its star, and belongs to the class of planets known as hot Jupiter
Hot Jupiter
Hot Jupiters are a class of extrasolar planet whose mass is close to or exceeds that of Jupiter...
s. A 2008 study concluded that the WASP-2b system (among others) is a binary star
Binary star
A binary star is a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, comes, or secondary...
system allowing even more accurate determination of stellar and planetary parameters.