Gamma Geminorum
From Wikipedia, the free encyclopedia
 Alhena is the γ star in the constellation of Gemini. |
|
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Gemini |
| Right ascension | 06h 37m 42.7s |
| Declination | +16° 23′ 57″ |
| Apparent magnitude (V) | 1.93 |
| Characteristics | |
| Spectral type | A0 IV |
| U-B color index | 0.06 |
| B-V color index | 0.00 |
| Variable type | ? |
| Astrometry | |
| Radial velocity (Rv) | -12.1 km/s |
| Proper motion (μ) | RA: -2.04 mas/yr Dec.: -66.92 mas/yr |
| Parallax (π) | 31.12 ± 2.33 mas |
| Distance | 105 ± 8 ly (32 ± 2 pc) |
| Absolute magnitude (MV) | -0.61 |
| Details | |
| Mass | 2.8 M☉ |
| Radius | 4.4 R☉ |
| Luminosity | 160 L☉ |
| Temperature | 9,750 K |
| Metallicity | ? |
| Rotation | 32 km/s. |
| Age | ? years |
| Other designations | |
Gamma Geminorum (γ Gem / γ Geminorum) is a star in the constellation Gemini. It has the traditional names Alhena and Almeisan. It is known as 井宿三 (the Third Star of the Well) in Chinese.
Alhena is 105 light years distant from Earth, and has an apparent magnitude of 1.93 (absolute magnitude −0.7) and belongs to the spectral class A0. It is a spectroscopic binary with a faint class-G companion.
The name Alhena is from the Arabic الهنعه Al Han'ah, "the brand" (on the neck of the camel), whilst the alternate name Almeisan is from the Arabic المیسان Al Maisan, "the shining one."
[edit] Alhena as a name
Alhena was the name of a Dutch ship that rescued many people from an Italian cruise liner, the Principessa Mafalda, in October 1927.[1] In addition, the American attack cargo ship USS Alhena was named after the star.
[edit] References
- ^ http://www.markos.it/quaderni/plata.htm Italian account of the Principessa Malfeda.
|
||||||||
 |
This subgiant star-related article is a stub. You can help Wikipedia by expanding it. |
