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Spectroscopic binary; Corona Australis From Wikipedia, the free encyclopedia
HD 178322, also known as HR 7257 or rarely 45 G. Coronae Australis, is a double-lined spectroscopic binary located in the southern constellation Corona Australis. It has a combined apparent magnitude of 5.86,[2] making it faintly visible to the naked eye under ideal conditions. The system is located relatively far at a distance of roughly 1,550 light-years based on Gaia DR3 parallax measurements,[1] and it is currently receding with a heliocentric radial velocity of 13.3 km/s.[6] At its current distance, HD 178322's brightness is diminished by an extinction of 0.28 magnitudes[15] and it has an absolute magnitude of −2.31.[7] The system has a high peculiar velocity of 28.9+4.1
−7.9 km/s,[11] indicating that it may be a runaway star system; it is said to be part of the Scorpius-Centaurus Association.[16]
The components of HD 178322 are both B-type main-sequence stars with stellar classifications of B5 V and B6 V respectively.[3] Both stars have roughly 4.4 times the mass of the Sun[10] and they spin moderately with projected rotational velocities of 45 km/s.[9] The primary has 3.26 times the radius of the Sun[9] and it radiates 11,749 times the luminosity of the Sun[12] from its photosphere at an effective temperature of 15,488 K. The companion has 3.07 times the Sun's girth[9] and it radiates 513 times the luminosity of the Sun[12] from its photosphere at an effective temperature of 14,454 K.[12] Both stars take roughly 12 days to complete a relatively circular orbit[8] at a separation of 0.235 AU.[9] The system is estimated to be 50 million years old.[11]