Gamma Virginis

Did You Know?

• At 2.8 degrees north of the ecliptic, Gamma Virginis can be occulted by the Moon and rarely by planets.
• In June 2011 Saturn passed a quarter of a degree south of Porrima.

Name

Gamma Virginis is the Latinised form of the Bayer designation γ Virginis. The traditional name Porrima comes from ancient Rome, where Porrima (also called Antevorta) was one of the Camenae, goddesses of prophecy. In 2016, the International Astronomical Union's Working Group on Star Names approved Porrima for Gamma Virginis A. In the Calendarium of Al Achsasi Al Mouakket, the star was called Laouiyet al Aoua, translated into Latin as Angulus Latratoris, meaning 'the angle of the barker'. This star, together with Beta, Eta, Delta, and Epsilon Virginis, formed Al ʽAwwāʼ, the Barker. In Chinese, Gamma Virginis is part of an asterism called Left Wall of Supreme Palace Enclosure, and its individual name is 東上相 (Dōngshǎngxiāng), westernized as Shang Seang, meaning 'the High Minister of State'.

Properties

Gamma Virginis is a binary star whose two components have nearly equal apparent magnitudes of 3.65 and 3.56 and are both of spectral type F0V. Their orbital period is 169 years. Until the early 1990s the pair was easily resolved by amateur astronomers, but by 2011 the apparent separation had become small, requiring larger telescopes or techniques such as speckle interferometry. The last periapsis occurred in 1836, and by 2020 the distance had widened enough for viewing with a small telescope. The system's combined apparent magnitude is 2.9, and it lies about 39 light-years from the Sun. Although slight variability was once reported, it is now considered unlikely. The system is estimated to be 1.14 billion years old, based on X-ray emissions.