Porrima

Observational Data
Designation |  Gamma Virginis
29 Virginis
Right ascension |  12h 41m 39.64344s[1]
Declination |  -01° 26′ 57.7421″[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]

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 618 mas/yr (milliarcseconds per year).[3] The name of the star derives from the Latin for the Roman goddesses of prophecy.[4]

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 169 years.[5] Their orbit is highly elliptical meaning their separation varies from 5 AU up to 81 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 7,100 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 20.42 km.s[1]

## References[edit]

1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Gamma Virginis from the SIMBAD Astronomical Database
2. ↑ 2.0 2.1 2.2 Porrima, Gamma Virginis, 29 Virginis, HD110379, HIP61941, HR4825. Retrieved on 2018-12-28.
3. ↑ 3.0 3.1 A Close, Quick, and Beautiful Double Star. Retrieved on 2018-12-29.
4. ↑ 4.0 4.1 4.2 Porrima. Retrieved on 2018-12-29.
5. ↑ See the Moon hide double star Porrima then get close to Jupiter on 3—4 June. Retrieved on 2018-12-29.

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Star

General|

Hertzsprung–Russell diagram · Open cluster · Star chart · Star magnitude · Starlight problem · Supernova

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Cygnus OB2-12 · Eta Carinae · LBV 1806-20 · MWC 314 · P Cygni · Pistol Star · Rho Cassiopeiae · RW Cephei · S Doradus · S Persei · VY Canis Majoris · Zeta Scorpii · 6 Cassiopeiae

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Procyon

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Binary stars|

Acrux · Alpha Centauri · Luyten 726-8 · Sirius