Sigma Arae
Sigma Arae is the Bayer designation for a star in the southern constellation of Ara. It is visible to the naked eye with an apparent visual magnitude of +4.575. The distance to this star, based upon an annual parallax shift of 8.62 mas, is around.
This is an A-type main sequence star with a stellar classification of A0 V. Unusually for an A-type star, X-ray emissions with a luminosity of have been detected from Sigma Arae. Normally this is explained by the presence of a lower mass orbiting companion star. However, such a scenario does not appear to hold true for this star. Instead, the signature of a surface magnetic field has been detected with a strength of roughly, indicating the source of the X-rays may be surface magnetic activity.
