Abstracts of Papers on Intrinsic Colours
Cramer N. (1982, A&A 112, 330)
Abstract
Estimators of the intrinsic Geneva [U-B] and [B-V] colours of O, B, and
early A-type stars with log g > 3.5 are derived empirically in the
three-parameter reddening-free (X,Y,Z) representation. These parameters
resolve the effect pf temperature and gravity (i.e. MK types, parameters
X and Y) as also of magnetic fields (Ap phenomenon, parameter Z). The estimators
are shown to be affected essentially in the same sense as the true {U,B,V]
colours by variations of the main astrophysical quantities. The intrinsic
colours are thus correctly reproduced regardless of prior knowledge
concerning evolutionary status, duplicity, rotational velocity or Ap
chasracteristics of the stars observed. The empirical relations are shown to
be in excellent agreement with Kurucz's (1979) atmosphere models, and the
MK-type vs X, Y, [U-B]o, [B-V]o relations are given.
Kilkenny D., Whittet D.C.B. (1985, MNRAS 216, 127)
Abstract
Photoelectric uvby observations are presented for 43 late O-type to
early A-type supergiants. The data are combined with published results to
extend the Zhang determination of the intrinsic colour lines in the
(b-y)/C1 diagram.
Meynet G., Hauck B. (1985, A&A 150, 163)
Abstract
The aim of this research note is to expose a photometric method to determine
the intrinsic values of the Geneva colour index (B2-V1) for the supergiants
of spectral types A and F. We present the different stages which led us to this
objective, and test our method with a few stars belonging to clusters for
which we found colour excesses in the literature. We indicate a list of
stars classified as supergiants which behave photometrically as dwarfs.
Schuster W.J. (1984, Rev. Mex. 9, 53)
Abstract
We present data fundamental for the study of B-type stars. Interstellar
reddening ratios, intrinsic colors, comparison stars, reddening-free indices,
and calibrations for MK spectral types, effective temperature, and
absolute visual magnitude are given. In particular we discuss briefly the
use of 13C photometry for measuring stellar distances and for studying
intrinsic excesses of Be and shell stars.
epaunzen@physics.muni.cz
Last update: 7 Novembre 1995