Predicting Stellar Angular Diameters from $V$, $I_C$, $H$, $K$ Photometry

Abstract

Determining the physical properties of microlensing events depends on having accurate angular sizes of the source star. Using long-baseline optical interferometry we are able to measure the angular sizes of nearby stars with uncertainties $\le 2\%$. We present empirically derived relations of angular diameters that are calibrated using both a sample of dwarfs/subgiants and a sample of giant stars. These relations are functions of five color indices in the visible and near-infrared, and have uncertainties of 1.8-6.5% depending on the color used. We find that a combined sample of both main-sequence and evolved stars of A-K spectral types is well fit by a single relation for each color considered. We find that in the colors considered, metallicity does not play a statistically significant role in predicting stellar size, leading to a means of predicting observed sizes of stars from color alone.

8 pages, 1 figure, accepted for publication in MNRAS

References in corpus (8)

• The NumPy array: a structure for efficient numerical computation
• First Results from the CHARA Array VII: Long-Baseline Interferometric Measurements of Vega Consistent with a Pole-On, Rapidly Rotating Star
• CHARA Array Measurements of the Angular Diameters of Exoplanet Host Stars
• Revised Filter Profiles and Zero Points for Broadband Photometry
• A near-infrared interferometric survey of debris disk stars. I. Probing the hot dust content around epsilon Eridani and tau Ceti with CHARA/FLUOR
• Eleven Exoplanet Host Star Angular Diameters from the CHARA Array
• The angular sizes of dwarf stars and subgiants - Non-linear surface brightness relations in BVRcIc from interferometry
• Angular Diameters of the G Subdwarf $\mu$ Cassiopeiae A and the K Dwarfs $\sigma$ Draconis and HR 511 from Interferometric Measurements with the CHARA Array