HD 86320
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HD 86320 (HIP 48320; 18 G. Chamaeleontis) is a binary star located in the southern circumpolar constellation Chamaeleon. With a combined apparent magnitude of 6.49,[3] the system is a challenge to view with the naked eye, even under ideal conditions. When resolved, the apparent magnitudes of the components are 6.69 and 8.62 respectively.[4] The system is located relatively far at a distance of 820 light years based on Gaia DR3 parallax measurements,[2] and it is drifting away from the Solar System with a heliocentric radial velocity of roughly 12.1 km/s.[7] It has an absolute magnitude of −0.54.[1]
The binary natue of this system was first observed in a 1991 Hipparcos multiple star survey.[4] A preliminary orbit was calculated for the system in 2016. In this solution, the stars take 63.52 years to circle each other in an eccentric orbit at a separation of 0.1583".[8] As of 2021, the 8th magnitude companion is located roughly 0.1" away at a position angle of 344°.[4]
The system has a combined spectral classification of B8 IV,[5] indicating that it is a slightly evolved B-type subgiant that is beginning to cease hydrogen fusion at its core. The primary has 3.07 times the mass of the Sun[9] and 4.95 times the radius of the Sun.[10] It radiates 332.2 times the luminosity of the Sun[2] from its photosphere at an effective temperature of 10,257 K,[9] giving it a bluish-white hue when viewed in the night sky. HD 86320 A has a solar metallicity,[11] and it is estimated to be 346 million years old.[13] It spins rapidly with a projected rotational velocity that is greater than 250 km/s.[12] The companion has 1.6 times the mass of the Sun based on the orbital solution.[8]
