Rotational Velocities And Radii Of Low-mass Pre-main Sequence Stars In NGC 2264
Abstract
Stellar radii and rotational velocities are crucial fundamental parameters which constrain theoretical models describing pre-main sequence (PMS) evolution. We have obtained high dispersion spectra for a sample of low-mass PMS stars in NGC 2264 (age 2 - 4 Myr) in order to measure v sin i values. Our sample includes 75 stars brighter than V=17.0 for which accurate rotation periods are known from photometric monitoring. By combining rotation periods with measured projected rotational velocities, we can determine the radius for these stars to within a factor of sin i. This method has only been employed for two clusters of T Tauri stars so far; the Orion Nebula Cluster (ONC) with an age 1 Myr (Rhode et al. 2001, AJ 122, 3258), and IC 348 with an age 1.5 Myr (Nordhagen et al. 2006, AJ 132, 1555). We compare the minimum stellar radius (R sin i) for each star to the radius derived from bolometric luminosities and effective temperatures. These results are discussed in the context of angular momentum evolution by comparing the mean radii of the stars in this cluster with those in the ONC and IC 348.
- Publication:
-
American Astronomical Society Meeting Abstracts #210
- Pub Date:
- May 2007
- Bibcode:
- 2007AAS...210.8708H