2014/09/01 by L. S. Lyubimkov, Д. Б. Поклад, D. B. Poklad
Physics and Astronomy · #Astronomical and nuclear sciences #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Photometry (optics) #Physics #Red supergiant #Stars #Stellar, planetary, and galactic studies #Supergiant #astro-ph.SR
paper · pdf · doi:10.3103/s0884591314050055
published as Kinematics and Physics of Celestial Bodies, 2014, Vol. 30, No. 5, pp. 244-254 · 11 pages, 3 figures, 2 tables
openalex publication_date 2014/09/01 · arxiv created 2014/12/22 · arxiv updated 2014/12/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
A method for determining the effective temperature T eff of G- and K-type giants and supergiants is proposed. The method is based on the use of two photometric indices free from the interstellar absorption influence: the Q index in the UBV photometric system and the [c 1] index in the uvby system. Empirical relations between the T eff values found for nearby and bright G- and K-type giants and supergiants with the use of the infrared fluxes method (IRFM), on the one hand, and the observed Q and [c 1] indices for these stars, on the other hand, are plotted. A systematic discrepancy between the dependences of T eff on Q for the stars with standard and reduced metallicities is found. Approximating the plotted dependences with second-order polynomials, one can obtain a relatively simple and a rather accurate method for determining the T eff value in the range of 3800 ≤ T ≤ 5100 K (based on the Q index) or 4900 ≤ T eff ≤ 5500 K (based on the [c 1] index).