Cool stars: effective temperatures, angular diameters, and reddening determined from 1 - 5 micron flux curves and model atmospheres.
Abstract
We compare observed infrared flux curves of cool stars with theoretical predictions in order to assess the model atmospheres and to derive useful stellar parameters. The atmospheres by Johnson accurately describe 1-5 m flux curves by Strecker et al. for 19 giants and supergiants from KO to M9, three Miras, and two carbon stars. This comparison yields four quantities for each star: (1) the effective temperature, determined from flux curve shape alone; (2) the angular diameter, determined from the magnitudes of the fluxes; (3) the reddening; and (4) the wavelength of the flux maximum. Comparison with previous results verifies the accuracy of our temperature scale (which shows greatly reduced scatter when plotted against the color R - 1 instead of spectral type). Our method for deriving angular sizes appears to be more accurate than any known direct measurement. The reddening is well correlated with published values but is systematically larger by about k mag in E(B - V). The flux peak shifts slightly to longer wavelength with advancing spectral type. Subject headings: infrared: spectra - spectrophotometry - stars: atmospheres - stars: late-type
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1979
- DOI:
- 10.1086/156910
- Bibcode:
- 1979ApJ...228..838S
- Keywords:
-
- Atmospheric Models;
- Cool Stars;
- Infrared Spectra;
- Late Stars;
- Light Curve;
- Stellar Atmospheres;
- Stellar Temperature;
- Diameters;
- Giant Stars;
- Interpolation;
- Interstellar Extinction;
- Stellar Spectrophotometry;
- Temperature Scales;
- Wavelengths;
- Astrophysics;
- Atmospheres:Late-Type Stars;
- Diameters:Late-Type Stars;
- Infrared Spectra:Late-Type Stars;
- Late-Type Stars:Temperatures;
- Stellar Atmospheres:Models