HD_195019
HD 195019
Binary star in the constellation Delphinus
HD 195019 is a binary star system in the northern constellation of Delphinus. The brighter star has a close orbiting exoplanet companion. This system is located at a distance of 122 light years from the Sun based on parallax measurements,[1] but it is drifting closer with a radial velocity of −91.3 km/s.[6] Although it has an absolute magnitude of 4.01,[5] at that distance the system is considered too faint to be viewed with the naked eye, having a combined apparent visual magnitude of 6.87.[5] However, it should be readily visible with a pair of binoculars or a small telescope.[13]
The spectrum of the primary member, designated component A, presents as a G-type main-sequence star with a stellar classification of G1V.[3] An older stellar classification of G3 V/IV[14] suggested it may be near the end of its main sequence lifespan and is evolving into a subgiant star.[13] This is an older star with an estimated age of nearly 8[8] billion years and a low level of magnetic activity in its chromosphere.[8] The abundance of iron is near solar.[9] The star has a mass similar to the Sun but a larger radius. It is radiating 2.23 times the luminosity of the Sun from its photosphere at an effective temperature of 5,825 K.[8]
The co-moving companion, component B, was first reported by G. W. Hough in 1881. As of 2016, it is located at an angular separation of 3.40″ along a position angle of 334° relative to the primary.[2] This corresponds to a projected separation of 131 AU. This is a K-type star with 70% of the mass of the Sun[10] and is magnitude 10.60.[2]