GAMMA VIRGINIS

'Gamma Virginis' (γ Vir / γ Virginis) is a star in the constellation Virgo. It also has the traditional name 'Porrima'.
Gamma Virginis is a binary star, consisting of two stars of approximately equal apparent magnitudes 3.48 and 3.50, and of spectral type F0V. With an orbital period of 168.68 years (calculated by Heintz at Sproul Observatory in 1990) until the beginning of the 1990s it was an easy object for amateur astronomers, but now the smaller apparent distance between the stars requires a larger telescope. The last time they were at periapsis was in 1836. The distance will again be wide enough in 2020 to view with a small telescope. The star system has a combined apparent magnitude of 2.9. The system is 32 light years away from the Sun.
As Gamma Virginis is close to the ecliptic, it can be occulted by the Moon and (extremely rarely) by planets.

Contents

Changes of distance and position angle

External links

Changes of distance and position angle

This table shows the apparent distance between the two stars and their relative position angle: first three columns show data predicted from an orbit calculated in 1937, the next three columns show observations reported by the Hanwell Community Observatory.

Predicted from 1937 Strand orbit			Observations 2003 to 2005
Year	distance	position angle	Date	distance	position angle
1995	2.5"	280
2000	1.8"	267
2002	1.5"	259
2003			2003 Dec.	0.6 arcsec.	219°
2004	1.2"	246	2004 Dec.	0.4 arcsec.	177°
2005			2005 April	0.27-0.29"	161±0.6°
2006	0.8"	221
2008	0.4"	126
2010	0.9"	44

External links

★ SIMBAD Query results for HD 110379

★ SIMBAD Query results for HD 110380