B_Serpentis
36 Serpentis
Star in the constellation Serpens
36 Serpentis is a binary star[14] system in the equatorial constellation of Serpens. It has the Bayer designation b Serpentis, while 36 Serpentis is the Flamsteed designation.[13] The system is visible to the naked eye as a dim, white-hued point of light with a combined apparent visual magnitude of 5.09.[2] It is located 162 light years away from the Sun based on parallax,[1] and is moving closer with a radial velocity of −8 km/s.[8]
This is a spectroscopic binary star system with a long orbital period of 52.8 years and a high eccentricity of 0.83. The combined mass of the pair is 3.09±0.28 M☉.[6] Gray et al. (2017) found a merged stellar classification of A2IV-Vn for this system,[5] while Cowley et al. matched it with a class of A3Vn,[4] where the 'n' indicates "nebulous" lines caused by rapid rotation.
The primary component is a Lambda Boötis star, meaning that it has solar-like amounts of carbon, nitrogen, and oxygen, while containing very low amounts of iron peak elements.[15] It is an A7[6] class main sequence star of visual magnitude 5.2[3] that is spinning rapidly, showing a projected rotational velocity of 229.[12] The star is 723[9] million years old with around double the mass of the Sun. It is radiating 19[2] times the Sun's luminosity from its photosphere at an effective temperature of 8,246 K.[11]
The cooler secondary component, a G0 star,[6] is the source for the X-ray emission that has been detected coming from this system.[6] It has a visual magnitude of 7.8.[3]