HIP 12961
Encyclopedia
HIP 12961 is a dim red dwarf
star
located approximately 75 light-year
s away in the constellation
of Eridanus
. It is one of the largest and brightest M class red dwarf stars known. In 2009 an extrasolar planet
orbiting this faint star has been announced.
which orbits the star. This planet has at least half the mass of Jupiter
and takes over eight weeks to orbit the star at a semimajor axis of approximately 0.25 AU
. The planet's existence was announced in a press release in October 2009, but no discovery paper has yet been made available.
Red dwarf
According to the Hertzsprung-Russell diagram, a red dwarf star is a small and relatively cool star, of the main sequence, either late K or M spectral type....
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...
located approximately 75 light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...
s 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 Eridanus
Eridanus (constellation)
Eridanus is a constellation. It is represented as a river; its name is the Ancient Greek name for the Po River. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations. It is the sixth largest of the modern...
. It is one of the largest and brightest M class red dwarf stars known. In 2009 an extrasolar planet
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 this faint star has been announced.
Planetary system
HIP 12961 b is an extrasolar planetExtrasolar 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...
which orbits the star. This planet has at least half the mass of 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,...
and takes over eight weeks to orbit the star at a semimajor axis of approximately 0.25 AU
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
. The planet's existence was announced in a press release in October 2009, but no discovery paper has yet been made available.