Astronomy and Astrophysics – Astrophysics
Scientific paper
1999-09-08
Astronomy and Astrophysics
Astrophysics
10 pages, 3 figures, to appear in Stellar Clusters and Associations: Convection, Rotation, and Dynamos, Mondello, Italy, May 1
Scientific paper
Focusing on ROSAT results for clusters in the $\sim 20-600$ Myr range, I first summarize our current understanding of the X-ray activity - rotation - age relationship. Then, the problem of the Hyades K and M dwarfs binaries is addressed: 1. most K and M-type binaries in wide systems are X-ray brighter than single stars; 2. binaries seem to fit into the same activity - rotation relationship as single stars. Points 1. and 2. suggest that the distributions of rotations of single and binary stars should also show a dicothomy, but the few available rotational data do not support the existence of such a dicothomy. Rotational periods for a larger sample of binary and single stars should be acquired before any conclusion is drawn. Finally, I discuss the topic whether the activity-age dependence is unique, as commonly thought. Whereas the comparison of Praesepe to the Hyades might imply that this is not the case, the X-ray activity of a sample of Hyades-aged field stars instead supports the common thinking.
No associations
LandOfFree
Coronal activity among open cluster stars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Coronal activity among open cluster stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Coronal activity among open cluster stars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-88894