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The Kinematics of Active Late Type Stars Observed by the ROSAT Wide-Field Camera

Jeffries, R.D.; Jewell, S.J.


S.J. Jewell


A sample of single, main-sequence late-type stars detected during the ROSAT Wide Field Camera EUV all-sky survey is kinematically investigated. It is confirmed that the galactic velocity dispersion of magnetically active objects, as defined by the ratio of EUV to bolometric flux, is substantially less than that of a random sample of late-type stars. This is due to the relationships between rotation and magnetic activity, age and rotation, and velocity dispersion and age. It is found, however, that the choice of only the most active stars does not decrease the velocity dispersions any further, and this may be evidence either for a long spin-down time-scale for the dMe stars that constitute the majority of this sample, or that very young stars are clumped around discrete velocity vectors that are somewhat separated in velocity space. A cluster analysis of the data reveals strong evidence for groups in the kinematic data that have space motions coincident with the Local Association and Sirius supercluster streams. These stellar streams are associated with the Pleiades and Ursa Major open clusters, with ages of.


Jeffries, R., & Jewell, S. (1993). The Kinematics of Active Late Type Stars Observed by the ROSAT Wide-Field Camera. Monthly Notices of the Royal Astronomical Society, 264(1),

Journal Article Type Article
Acceptance Date Feb 19, 1993
Publication Date 1993-09
Deposit Date Feb 8, 2024
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Publisher Oxford University Press
Peer Reviewed Peer Reviewed
Volume 264
Issue 1