Theta Pyxidis,Latinized fromθ Pyxidis, is a redM-typegiant in the constellation Pyxis. It is approximately 500 ± 30light years fromEarth.[1] It is of spectral type M1III and semi-regular variable with two measured periods of 13 and 98.3 days, and an average visual magnitude of 4.71,[4] It shines with aluminosity approximately 970 times that of the Sun and has a surface temperature of 3825 K.[8] It has a diameter around 54 times that of the Sun.[7]
Theta Pyxidis is moving through the Galaxy at a speed of 22.8 km/s relative to the Sun. Its projected Galactic orbit carries it between 21,200 and 24,700 light years from the center of the Galaxy. It came closest to the Sun 5.8 million years ago when it had brightened to magnitude 3.12 from a distance of 241 light years.[citation needed]
^abcGutierrez-Moreno, Adelina; et al. (1966), "A System of photometric standards",Publications of the Department of Astronomy University of Chile,1, Publicaciones Universidad de Chile, Department de Astronomy:1–17,Bibcode:1966PDAUC...1....1G.
^Keenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins catalog of revised MK types for the cooler stars".Astrophysical Journal Supplement Series.71: 245.Bibcode:1989ApJS...71..245K.doi:10.1086/191373.
