A&A Supplement series, Vol. 128, February II 1998, 207-219
Received January 13; accepted June 17, 1997
P.L. Hammersley, M. Jourdain de Muizon, M.F. Kessler, P. Bouchet, R.D. Joseph, H.J. Habing, A. Salama, and L. Metcalfe
Send offprint request: P.L. Hammersley
Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife, Spain
DESPA, Observatoire de Paris, Meudon, France
LAEFF, VILSPA, P.O. Box 50727, 28080 Madrid, Spain
ESA, VILSPA, P.O. Box 50727, 28080 Madrid, Spain
European Southern Observatory, Casilla 19001, Santiago 19, Chile
IRTF, Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, HI96822, U.S.A.
Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, The Netherlands
We present N, 8.7 m, 9.8 m 12.5 m and Q bolometry of 26 stars which were observed on the IRTF. These are primarily K giants which have been well measured at other wavelengths and are chosen to be single and non-variable. Hence the data presented provides a new homogeneous set of mid IR standards. As a test of part of the calibration strategy of ISO over this wavelength range, the zero points have been set using the Kurucz model grids (1993) to predict the mid IR magnitudes from near IR data. An analysis of the errors involved is presented and a comparison with more direct methods for the determination of the zero points suggest an possible error of 0.015 mags, although the source of this error is unclear as it is at the level of the uncertainty in the more direct methods. The effect of the SiO fundamental on the spectral energy distributions of K giants is discussed.
keywords: techniques: photometric -- stars: fundamental parameters -- infrared: stars