Effect of chromospheric activity on the mean colours of late-type stars II. Is (B - V)0 also affected?

DOI: 
Publication date: 
01/01/2003
Main author: 
Amado P.J.
IAA authors: 
Amado P.J.
Authors: 
Amado P.J.
Journal: 
Astronomy and Astrophysics
Publication type: 
Article
Volume: 
404
Pages: 
631-636
Number: 
Abstract: 
We confirm the existence of an 'excess' in the mean dereddened (U - B)0 colour of active single-lined spectroscopic giants over quiescent stars of the same spectral type and find evidence for this 'excess' in (B - V)0, although at a lower scale, when plotted against (R - I)0. This result suggests that the use of (B - V)0 calibrations to determine fundamental parameters or spectral types for late-type active stars should be taken with caution. Since magnetic activity is definitely involved, these and similar calibrations using (U - B)0 and/or (B - V)0 should not be used for the study of late-type young clusters' members or late-type pre-main sequence stars without some consideration. Instead, near-infrared colours like (R - I)0 should be better temperature indicators for these stars.
Database: 
SCOPUS
Keywords: 
Stars: Activity; Stars: Fundamental parameters; Stars: Late-type