Iota Virginis

Background

The system bears the traditional name Syrma, derived from the Ancient Greek σύρμα meaning 'train (of a garment)'. This name was approved by the International Astronomical Union's Working Group on Star Names on 12 September 2016, and is attributed to the brightest component, Iota Virginis A. In Chinese astronomy, Iota Virginis is part of an asterism called Neck, which also includes Kappa Virginis, Phi Virginis, and Lambda Virginis.

Iota Virginis is an astrometric binary: the secondary component regularly perturbs the primary, causing it to wobble around the system's barycenter. A preliminary orbit with a period of 55 years has been calculated. The primary, Iota Virginis A, is a yellow star of spectral class F7IV-V, with 1.44 times the Sun's mass, 2.89 times its radius, and radiating 10 times the Sun's luminosity at an effective temperature of 6,055 K. Its projected rotational velocity is 16 km/s.

Iota Virginis B has not been directly detected. Based on its inferred mass, it may be either a main-sequence star or a white dwarf.

This companion is responsible for the drifting radial velocity observed in the primary. In 2011, it was noticed that the faint K-type main-sequence star HD 125354 shares a similar proper motion through space and is likely physically associated with the system; a 2015 paper supported this hypothesis. HD 125354 lies about 1.2 light-years from Iota Virginis, at a similar distance from the Sun within the margin of error, and is itself a close binary with another star separated by 0.33 arcseconds.