A kinematically unbiased search for nearby young stars in the Northern hemisphere selected using SuperWASP rotation periods

Binks, A.S.; Jeffries, R.D.; Maxted, P.F.L.

Abstract

We present a kinematically-unbiased search to identify young, nearby low-mass members of kinematic moving groups (MGs). Objects with both rotation periods shorter than 5 days in the SuperWASP All-Sky Survey and X-ray counterparts in the ROSAT All-Sky Survey were chosen to create a catalog of several thousand rapidly-rotating, X-ray active FGK stars. These objects are expected to be either young single stars or tidally-locked spectroscopic binaries. We obtained optical spectra for a sub-sample of 146 stars to determine their ages and kinematics, and in some cases repeat radial velocity (RV) measurements were used to identify binarity. Twenty-six stars are found to have lithium abundances consistent with an age of <=200 Myr, and show no evidence for binarity and in most cases measurements of H-alpha and v\sin i support their youthful status. Based on their youth, their radial velocities and estimates of their 3-dimensional kinematics, we find 11 objects that may be members of known MGs, 8 that do not appear associated with any young MG and a further 7 that are close to the kinematics of the recently proposed "Octans-Near" MG, and which may be the first members of this MG found in the northern hemisphere. The initial search mechanism was ~18 per cent efficient at identifying likely-single stars younger than 200 Myr, of which 80 per cent were early-K spectral types.

Citation

Binks, A., Jeffries, R., & Maxted, P. (2015). A kinematically unbiased search for nearby young stars in the Northern hemisphere selected using SuperWASP rotation periods. Monthly Notices of the Royal Astronomical Society, 452(1), 173-192. https://doi.org/10.1093/mnras/stv1309

• Journal Article Type: Article
• Acceptance Date: Jun 8, 2015
• Online Publication Date: Jul 1, 2015
• Publication Date: Sep 1, 2015
• Publicly Available Date: May 26, 2023
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 452
• Issue: 1
• Pages: 173-192
• DOI: https://doi.org/10.1093/mnras/stv1309
• Keywords: stars, late-type, pre-main-sequence
• Publisher URL: https://doi.org/10.1093/mnras/stv1309