Delta Indi, Latinized from δ Indi, is a binary star[4] system in the southern constellation of Indus. It is visible to the naked eye with a combined apparent visual magnitude of +4.40.[2] The brighter primary, designated component A, is magnitude 4.80 while the companion, component B, is magnitude 5.96.[3] Based upon an annual parallax shift of 14.07 mas as measured from Earth,[1] the system is located about 188 light years from the Sun.

The binary nature of this system was discovered by South African astronomer William Stephen Finsen from 1936 onward,[4] with his published orbital elements appearing in 1956.[9] The pair have an orbital period of 12.2 years, a semimajor axis of 0.176 arc seconds, and an eccentricity of around 0.03. Both components have been listed with a stellar classification of F0 IV by multiple authors, suggesting they are yellow-white hued F-type subgiant stars. However, their estimated masses don't match this classification, so Docobo and Andrade (2013) suggest the Hipparcos parallax may have been underestimated.[4]

References