53_Ophiuchi
53 Ophiuchi
Star system in the constellation Ophiuchus
53 Ophiuchi is a multiple star system in the equatorial constellation of Ophiuchus. It is visible to the naked eye as a faint star with a combined apparent visual magnitude of 5.80.[3] Located around 370 light years distant from the Sun based on parallax,[1] it is moving closer to the Earth with a heliocentric radial velocity of −14 km/s.[5] As of 2011, the visible components had an angular separation of 41.28″ along a position angle of 190°.[12] The primary may itself be a close binary system with a separation of 0.3692″ and a magnitude difference of 3.97 at an infrared wavelength of 562 nm.[13]
The magnitude 5.82[3] primary, designated component Aa, is an A-type main-sequence star with a stellar classification of A2 V.[4] It has 2.5[7] times the mass of the Sun and about 1.7[8] times the Sun's radius. The star is radiating 56 times the Sun's luminosity from its photosphere at an effective temperature of 9,311 K.[7] The widely spaced secondary, designated component B, is a magnitude 7.8[3] A-type subgiant star with a class of A8 IV.[4]