V701 Coronae Australis
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V701 Coronae Australis (HD 176723; HR 7197; 40 G. Coronae Australis), or simply V701 CrA, is a solitary,[16] yellowish-white hued variable star located in the southern constellation Corona Australis. It has an average apparent magnitude of 5.72,[17] making it faintly visible to the naked eye under ideal conditions. The object is located relatively close at a distance of 213 light-years based on Gaia DR3 parallax measurements,[1] and it is currently receding with a poorly constrained heliocentric radial velocity of 4 km/s.[6] At its current distance, V701 CrA's brightness is diminished by a quarter of a magnitude due to extinction[18] and it has an absolute magnitude of +1.55.[7]
The object was first suspected to be variable in 1990. The variations matched that of δ Scuti variables.[20] Three years later, it was confirmed to be variable and was given the variable star designation V701 Coronae Australis.[21] It ranges from magnitude 5.69 to 5.73[2] within 3.25 hours.[22]
V701 CrA has a stellar classification of F2 III/IV,[3] indicating that it is an evolved F-type star with the blended luminosity class of a subgiant and giant star. It has also been given a class of F0 IIIn,[4] indicating broad or nebulous absorption lines due to rapid rotation. It has 1.83 times the mass of the Sun[8] and a slightly enlarged radius of 2.85 R☉.[9] It radiates 17.5 times the luminosity of the Sun[1] from its photosphere at an effective temperature of 7,046 K.[11] The star spins rapidly with a projected rotational velocity of 265 km/s,[13] which causes it to have an equatorial bulge that is 26% larger than the poles.[23] It is metal deficient with an iron abundance 62% that of the Sun ([Fe/H] = −0.21)[12] and it is estimated to be 1.25 billion years old.[11] V701 CrA was considered to be a chemically peculiar star and was given a class of FpSr. Its peculiarity is now considered to be doubtful.[24]
