Astronomy and Astrophysics – Astrophysics
Scientific paper
1998-07-06
Be accpected for publication in the October 1998 issue of the PASP
Astronomy and Astrophysics
Astrophysics
16 pages (including 3 figures) and 3 tables
Scientific paper
10.1086/316241
A total of 597 radial-velocity observations for 112 stars in the ~1.6 Gyr old open cluster NGC 7789 have been obtained since 1979 with the radial velocity spectrometer at the Dominion Astrophysical Observatory. The mean cluster radial velocity is -54.9 +/- 0.12 km/s and the dispersion is 0.86 km/s, from 50 constant-velocity stars selected as members from this radial-velocity study and the proper motion study of McNamara and Solomon (1981). Twenty-five stars (32%) among 78 members are possible radial-velocity variable stars, but no orbits are determined because of the sparse sampling. Seventeen stars are radial-velocity non-members, while membership estimates of six stars are uncertain. There is a hint that the observed velocity dispersion falls off at large radius. This may due to the inclusion of long-period binaries preferentially in the central area of the cluster. The known radial-velocity variables also seem to be more concentrated toward the center than members with constant velocity. Although this is significant at only the 85% level, when combined with similar result of Raboud and Mermilliod (1994) for three other clusters, the data strongly support the conclusion that mass segregation is being detected.
Gim Munhwan
Hesser James Edward
McClure Robert D.
Stetson Peter B.
No associations
LandOfFree
The Open Cluster NGC 7789: I. Radial Velocities for Giant 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 The Open Cluster NGC 7789: I. Radial Velocities for Giant Stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Open Cluster NGC 7789: I. Radial Velocities for Giant Stars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-666107