Radial-velocity measurements in 20 young open clusters

Journal Article · Tue Aug 01 04:00:00 EDT 1989 · Astronomical Journal; (USA)

DOI:https://doi.org/10.1086/115162· OSTI ID:5402827

Liu, Tianxing; Janes, K A; Bania, T M ^[1]

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1. Boston Univ., MA (USA)

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. 25 refs.

• OSTI ID: 5402827
• Journal Information: Astronomical Journal; (USA), Journal Name: Astronomical Journal; (USA) Vol. 98; ISSN 0004-6256; ISSN ANJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BINARY STARS
COMPARATIVE EVALUATIONS
CORRELATIONS
MOTION
RADIAL VELOCITY
ROTATION
STAR CLUSTERS
STARS
VARIATIONS
VELOCITY