It bore the traditional name Sargas, of Sumerian origin.[14] Another possible origin is Persian for Arrow Head سر گز. The name 'Sar Gaz' is used in Iran as a star name, and was used for timing irrigation water shares.[15] In 2016, the IAU organized a Working Group on Star Names (WGSN)[16] to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.[17] It approved the name Sargas for the star θ Scorpii A on 21 August 2016 and it is now so included in the List of IAU-approved Star Names.[12]
The primary (θ Scorpii A) has a stellar classification of F1 III, with a luminosity class III indicating its luminosity is comparable to that of a F-type giant.[4] With a mass 3.10 times that of the Sun, it is radiating 1,400[3] times as much luminosity as the Sun from its outer envelope at an effective temperature of 6,294 K,[3] giving it the yellow-white-hued glow of an F-type star. This star is rotating rapidly, giving it an oblate shape with an equatorial radius 33% larger than the polar radius. The equatorial radius is about 36 R☉ while the polar radius is only about 26 R☉. This rapid rotation suggests that it formed via the merger of a binary star system.[3]
A magnitude 5.36 companion has been reported at an angular separation of 6.470 arcseconds,[20] but subsequent observers have failed to detect it, so it probably does not exist. However, a secondary, designated θ Scorpii B, has been detected at an angular separation of 0.538 arcseconds in 1991 by the Hipparcos satellite.[3]
^ abKeenan, Philip C.; McNeil, Raymond C. (October 1989). "The Perkins Catalog of Revised MK Types for the Cooler Stars". The Astrophysical Journal Supplement Series. 71: 245. Bibcode:1989ApJS...71..245K. doi:10.1086/191373. ISSN0067-0049.
^ abcJohnson, H. L.; et al. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory. 4 (99): 99. Bibcode:1966CoLPL...4...99J.
^Wilson, R. E. (1953). "General Catalogue of Stellar Radial Velocities". Carnegie Institute Washington D.C. Publication. Carnegie Institute of Washington D.C. Bibcode:1953GCRV..C......0W.
^Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub. ISBN978-1-931559-44-7.
^Hessman, F. V.; Dhillon, V. S.; Winget, D. E.; Schreiber, M. R.; Horne, K.; Marsh, T. R.; Guenther, E.; Schwope, A.; Heber, U. (2010). "On the naming convention used for multiple star systems and extrasolar planets". arXiv:1012.0707 [astro-ph.SR].
