2008/11/26 by G. T. van Belle, M. J. Creech-Eakman, A. Hart · 3 citations
Physics and Astronomy · #Angular diameter #Astronomy and Astrophysical Research #Black-body radiation #Calibration #Effective temperature #Luminosity #RADIUS #Scientific Research and Discoveries #Stars #Stellar classification #Stellar, planetary, and galactic studies #Supergiant #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2008.14146.x
Accepted for publication in MNRAS; contains 5 figures and 7 tables
arxiv created 2008/11/26 · openalex publication_date 2009/03/06 · arxiv updated 2015/05/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present angular diameters for 42 Luminosity Class (LC) I stars and 32 LC II stars that have been interferometrically determined with the Palomar Testbed Interferometer. Derived values of radius and effective temperature are established for these objects, and an empirical calibration of these parameters for supergiants will be presented as a function of spectral type and colours. For the effective temperature versus (V−K)0 colour, we find an empirical calibration with a median deviation of ΔT= 70 K in the range of 0.7 < (V−K)0 < 5.1 for LC I stars; for LC II, the median deviation is ΔT= 120 K from 0.4 < (V−K)0 < 4.3. Effective temperature as a function of spectral type is also calibrated from these data, but shows significantly more scatter than the TEFF versus (V−K)0 relationship. No deviation of TEFF versus spectral type is seen for these high-luminosity objects relative to LC II giants. Directly determined diameters range up to 400 R⊙, though are limited by poor distance determinations, which dominate the error estimates. These temperature and radii measures reflect a direct calibration of these parameters for supergiants from empirical means.