Castor Moving Group
Encyclopedia
The Castor Moving Group is a moving group, that is, a set of star
s with common velocities in space, thought to have a common origin. The stars that have been identified as part of the group include Castor
, Fomalhaut
, Vega
, α Cephei
and α Librae
. They are all of similar age.
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...
s with common velocities in space, thought to have a common origin. The stars that have been identified as part of the group include Castor
Castor (star)
Castor is the second brightest star in the constellation Gemini and one of the brightest stars in the night sky. Although it has the Bayer designation "alpha", it is actually fainter than Beta Geminorum...
, Fomalhaut
Fomalhaut
Fomalhaut is the brightest star in the constellation Piscis Austrinus and one of the brightest stars in the sky. Fomalhaut can be seen low in the southern sky in the northern hemisphere in fall and early winter evenings. Near latitude 50˚N, it sets around the time Sirius rises, and does not...
, Vega
Vega
Vega is the brightest star in the constellation Lyra, the fifth brightest star in the night sky and the second brightest star in the northern celestial hemisphere, after Arcturus...
, α Cephei
Alpha Cephei
Alpha Cephei is a second magnitude star in the constellation of Cepheus that is relatively close to Earth at only 49 light years...
and α Librae
Alpha Librae
Alpha Librae is the second brightest star in the constellation Libra . It has the traditional name Zubenelgenubi. The name, from Arabic الزبن الجنوبي , means "southern claw" and was coined before Libra was recognized as distinct from Scorpius...
. They are all of similar age.
Discovery and constituents
The moving group was first proposed by J. P. Anosova, and V. V. Orlov in 1990. Anosova and Orlov originally proposed 15 members. The membership of the group has not been established and there is some controversy over whether the group is real or spurious.Proposed member stars
- ζ LeporisZeta LeporisZeta Leporis is a white main sequence star approximately 70 light-years away in the constellation of Lepus. The star is suspected of being a spectroscopic binary star system, but this is yet to be confirmed. In 2001, an asteroid belt was confirmed to orbit the star.-Stellar components:Zeta...
- α CepheiAlpha CepheiAlpha Cephei is a second magnitude star in the constellation of Cepheus that is relatively close to Earth at only 49 light years...
- α1 LibraeAlpha LibraeAlpha Librae is the second brightest star in the constellation Libra . It has the traditional name Zubenelgenubi. The name, from Arabic الزبن الجنوبي , means "southern claw" and was coined before Libra was recognized as distinct from Scorpius...
- α2 LibraeAlpha LibraeAlpha Librae is the second brightest star in the constellation Libra . It has the traditional name Zubenelgenubi. The name, from Arabic الزبن الجنوبي , means "southern claw" and was coined before Libra was recognized as distinct from Scorpius...
- CastorCastor (star)Castor is the second brightest star in the constellation Gemini and one of the brightest stars in the night sky. Although it has the Bayer designation "alpha", it is actually fainter than Beta Geminorum...
- FomalhautFomalhautFomalhaut is the brightest star in the constellation Piscis Austrinus and one of the brightest stars in the sky. Fomalhaut can be seen low in the southern sky in the northern hemisphere in fall and early winter evenings. Near latitude 50˚N, it sets around the time Sirius rises, and does not...
- HD 51825
- ψ VelorumPsi VelorumPsi Velorum is a binary star in the constellation Vela. It is approximately 60.5 light years from Earth, making it the nearest star of the constellation....
- Gliese 351A
- Gliese 426 AB
- HD 117934
- HD 119124
- HD 162283
- HD 181321
- Gliese 842.2
- Gliese 896 AB
- TW Piscis AustriniTW Piscis AustriniTW Piscis Austrini is a dwarf star in the constellation Piscis Austrinus. It lies relatively close to the Sun, at an estimated distance of 24.9 light years....
- κ Phoenicis
- VegaVegaVega is the brightest star in the constellation Lyra, the fifth brightest star in the night sky and the second brightest star in the northern celestial hemisphere, after Arcturus...