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Radial-velocity measurements in 20 young open clusters

1989; Institute of Physics; Volume: 98; Linguagem: Inglês

10.1086/115162

1538-3881

Tianxing Liu, K. A. Janes, T. M. Bania,

Astronomical Observations and Instrumentation

view Abstract Citations (78) References (23) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Radial Velocity Measurements in 20 Young Open Clusters Liu, Tianxing ; Janes, Kenneth A. ; Bania, T. M. Abstract The further results of a program to determine the radial velocities of young open clusters are presented. Using the KPNO coude spectrograph coupled with the 1-m feed and 2.1-m telescopes, radial velocities have been measured for nearly one hundred stars, most of which are of spectral type B and A, in 20 young clusters. The combination of instruments and the use of cross-correlation techniques show that radial velocities of B and A type stars as faint as 10th magnitude can be determined with an internal precision of less than about 2 km/s. As expected, the uncertainties in the velocity determination for the young clusters are dominated by spectroscopic binary stars in these clusters. A third of the stars in the sample are found to be spectroscopic binaries, but with a large variation in the frequency of binaries from cluster to cluster. Because the time coverage is still limited, this should be considered a lower limit to the binary frequency. Cluster velocities are determined after eliminating binaries and known nonmember stars. The new velocities are compared with a model galactic rotation curve, as well as with previous velocity determinations. Publication: The Astronomical Journal Pub Date: August 1989 DOI: 10.1086/115162 Bibcode: 1989AJ.....98..626L Keywords: Open Clusters; Radial Velocity; A Stars; B Stars; Binary Stars; Galactic Rotation; Velocity Measurement; Astrophysics; CLUSTERS: OPEN full text sources ADS | data products SIMBAD (126)