ISO-SWS calibration and the accurate modelling of cool-star atmospheres ^*,**

III. A0 to G2 stars

¹ Instituut voor Sterrenkunde, KULeuven, Celestijnenlaan 200B, 3001 Leuven, Belgium
² Institute for Astronomy and Space Physics, Box 515, 75120 Uppsala, Sweden
³ GRAAL - CC72, Université de Montpellier II, 34095 Montpellier Cedex 5, France
⁴ Observatoire Royal de Belgique, Avenue Circulaire 3, 1180 Bruxelles, Belgium

Corresponding author: L. Decin, Leen.Decin@ster.kuleuven.ac.be

Received: 22 November 2001
Accepted: 2 December 2002

Abstract

Vega, Sirius, β Leo, α Car and α Cen A belong to a sample of twenty stellar sources used for the calibration of the detectors of the Short-Wavelength Spectrometer on board the Infrared Space Observatory (ISO-SWS). While general problems with the calibration and with the theoretical modelling of these stars are reported in Decin et al. ([CITE]), each of these stars is discussed individually in this paper. As demonstrated in Decin et al. ([CITE]), it is not possible to deduce the effective temperature, the gravity and the chemical composition from the ISO-SWS spectra of these stars. But since ISO-SWS is absolutely calibrated, the angular diameter () of these stellar sources can be deduced from their ISO-SWS spectra, which consequently yields the stellar radius (R), the gravity-inferred mass (M_g) and the luminosity (L) for these stars. For Vega, we obtained  mas,   ,    and   ; for Sirius  mas,   ,    and   ; for β Leo  mas,   ,    and   ; for α Car  mas,   ,    and    and for α Cen A  mas,   ,    and   . These deduced parameters are confronted with other published values and the goodness-of-fit between observed ISO-SWS data and the corresponding synthetic spectrum is discussed.