Porrima
Porrima (Gamma Virginis, 29 Virginis, HIP 61941) is a binary star system in the constellation of Virgo.[2] It is one of the few stars close enough to Earth that it can be seen to move a noticeable amount during a human lifetime, moving a total of around 618Â mas/yr (milliarcseconds per year).[3] The name of the star derives from the Latin for the Roman goddesses of prophecy.[4]
| Porrima | |
|---|---|
| Observational Data | |
| Designation | Gamma Virginis 29 Virginis |
| Right ascension | 12h 41m 39.64344s[1] |
| Declination | -01° 26â² 57.7421â³[1] |
| Constellation | Virgo |
| Type of object | Main sequence star |
| Magnitude | Apparent Mag: +2.74[1] Absolute Mag: +2.40[2] |
| Astrometry | |
| Distance from Earth | 38.11 ly[2] |
| Radial velocity | -20.42±0.4 km/s[1] |
| Proper motion | RA: -614.76 mas/yr[1] Dec.: 61.34 mas/yr[1] |
| Parallax | 85.58±0.60 mas[1] |
Both stars are F-type, main sequence stars with similar magnitudes of +3.6.[3] The two stars orbit their common barycentre with a period of 169Â years.[5] Their orbit is highly elliptical meaning their separation varies from 5Â AU up to 81Â AU.[4] As of 2010, the two stars can be resolved with a small telescope, though it requires high magnification (x200). It is one of the best double stars visible in the night sky.
The two stars are hotter than the sun, with surface temperatures of 7,100Â kelvin.[4] They are also slightly larger with radii 1.2 times and masses 1.4 times of the Sun and luminosities four times as much. The star system is actually approaching the Earth at around 20.42Â km.s[1]
References
- â 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Gamma Virginis from the SIMBAD Astronomical Database
- â 2.0 2.1 2.2 Porrima, Gamma Virginis, 29 Virginis, HD110379, HIP61941, HR4825. Retrieved on 2018-12-28.
- â 3.0 3.1 A Close, Quick, and Beautiful Double Star. Retrieved on 2018-12-29.
- â 4.0 4.1 4.2 Porrima. Retrieved on 2018-12-29.
- â See the Moon hide double star Porrima then get close to Jupiter on 3â4 June. Retrieved on 2018-12-29.