Groombridge 1830
|
|
Template:Astrobox begin1 Template:Star listings Template:Astrobox end Groombridge 1830 is a star.
Also known as GJ 451, HD 103095, BD+38 2285, SAO 62738, it is a yellow-orange class G8 subdwarf catalogued by Stephen Groombridge in the 1830s. Its high proper motion was noted by Friedrich Wilhelm Argelander in 1842.
It is 29.7 light years from Earth's Solar System, which means its absolute magnitude is almost equal to its apparent magnitude. It is a halo star; such stars account for only 0.1 to 0.2 percent of the stars near the Sun. It is in Ursa Major.
It is a binary star with a period of 175 days.
When discovered, it had the highest proper motion of any star known, replacing 61 Cygni in that department. Later it dropped to second place after the discovery of Kapteyn's Star, and still later to third place after the discovery of Barnard's Star. It is considerably farther away than either of those stars, however, which means its transverse velocity is greater.
Actually, it is the Sun which is following the motion of galaxy rotation by revolving around the center of the Milky Way; halo stars like Groombridge 1830 do not follow this galaxy rotation and thus are "standing still" and appear to be moving in "retrograde direction" at high speed.
| Contents |
Some facts about Groombridge 1830
- Parallax: 0.110 arcsecs
- Spectral type: G8 VIp
- Radial velocity: -98.8 km/s
- Proper Motion: 7.058 arcsecs/year
- Apparent Visual Magnitude: 6.42
- Absolute Visual Magnitude: 6.62
- Luminosity: 0.19 Solar Luminosities
See also
External links
- SolStation.com: Groombridge 1830 (http://www.solstation.com/stars/groo1830.htm)
Discovery of high proper motion
- AN 19 (1842) 393/394 (http://adsabs.harvard.edu//full/seri/AN.../0019//0000202.000.html) (in German)
- AN 20 (1843) 163/164 (http://adsabs.harvard.edu//full/seri/AN.../0020//0000091.000.html) (in German)
- AN 20 (1843) 279/280 (http://adsabs.harvard.edu//full/seri/AN.../0020//0000155.000.html)