Name: Greg Doppmann

Institution: NOAO

e-mail: gdoppmann(no-spam)noao.edu

Partner Contry: USA

Science Meeting: Yes

User Meeting: Yes

NGO Staff Meeting: Yes

Presentation: Yes

Format: Poster

Title: Testing Fundamental Evolutionary Tracks with High Resolution Spectroscopy of a Newly Discovered Pre-Main Sequence Binary

Co-author: Russel White David Charbonneau

Co-authors' Institutions: Univ. of Alabama, Huntsville CfA Harvard

Abstract:

Empirical measurements of basic stellar and substellar properties in pre-main sequence (PMS) objects are critical to our understanding of how and when these objects evolve toward the main sequence. Dynamical measurements of PMS binary systems are beginning to provide these fundamental data, if they can be accurately placed on an H-R diagram for comparison with PMS evolutionary models. A recent Phoenix discovery of a low-mass double-line spectroscopic binary in Chamaeleon has enabled dynamical mass measurements and constraints on the age of this young system. A dozen high resolution (R=50,000) Phoenix observations over an 8 month period have well-constrained the period and mass ratio. In addition, key physical properties of the primary and secondary (e.g. effective temperature, surface gravity and vsini rotation) are measured from detailed multicomponent spectral synthesis model fits using each of the three distinct K band absorption line-regions present in this data set.! With the placement of this system in the H-R diagram using the properties we determine spectroscopy, we will test the accuracy of theoretical model tracks using the independent mass information obtained from the orbital motion.