Pre-Main-Sequence Ages - Taurus and the Environmental Impact on Disc Lifetime

Thursday, 06 August 2015 1:30 p.m. — 2 p.m. MST

AURA Lecture Hall

NOIRLab South Colloquia
JON REES (University of Exeter, School of Physics and NOAO South Visiting Astronomer)

We have derived a new age for Taurus, one of the most important and well studied young star forming regions. Our new age of 3-4Myr is significantly older than the typically quoted 1Myr, but is fully consistent with the new age scale derived in Bell et al. (2013). The older age will potentially affect the previously derived stellar parameters,  including the mass function. Additionally we can state that Taurus shows an excess in disc fraction compared to other clusters of similar age, suggesting that discs survive longer in the low density, low mass environment. 

Determining ages (or masses) requires determination of extinctions. Previous surveys in Taurus have estimated stellar reddenings, but techniques differ between surveys, and the derived extinctions are not always consistent with other estimates.   In an effort to counter the high levels of differential reddening in Taurus while maintaining consistency across our dataset we have developed a Bayesian method of determining the extinction to a given star using iZJH photometry.