Brian's Home Page

Brian Chaboyer

I'm a Professor in the Physics and Astronomy Department at Dartmouth. In the Fall term, I will be teaching Astronomy 2/3. The course web sites can be accessed via Blackboard.

My research is in the general area of stellar evolution and stellar populations. I'm particulary interested in the ages of globular clusters (see a picture of their locations) and the formation of the Milky Way. Below is a brief summary of some of my current research projects.


SIM-'Lite' is a NASA telescope designed to obtain very accurate positions of stars. With this data, astronomers can search for Earth-like planets around near-by stars and determine the distances to stars in the Milky Way. SIM-'Lite' would be launched into an Earth-trailing orbit, and conduct observations for a minimum of 5 years. I am a member of the SIM-'Lite' science team, selected in 2001 to to determine the distances and ages of the oldest stars in our galaxy. SIM-`Lite' is currently under study by NASA. Further details on the observations that I would like to do on this telescope are given here .

Stellar Evolution

Much of my work involves the use of computer programs to model the structure and evolution of stars. Modeling the evolution of stars requires knowledge of a wide range of physical phenomena, including nuclear and atomic physics and fluid mechanics. A schematic illustration of how a stellar model is constructed highlights the important steps required to make a stellar model. My former graduate student Aaron Dotter and myself have calculated a large gride of stellar evolution models and isochrones which are available for public use.

The computer program I use to model the evolution of stars is not publicaly available, but it can be run using a simple web interface. This web interface is a work in progress, and if you encounter any difficulties, please e-mail me. The bulk of the web interface was designed by Susan Schwarz from Research Computing at Dartmouth.

Globular Clusters and Stellar Ages

I am involved in a variety of projects to study the ages of the oldest stars in the Milky Way. I am the principle investigator of a Hubble Space Telescope (HST) large program to determine parallaxs to some nearby metal-poor stars. We have been allocated 108 orbits of HST time (equivalent to 7 days) to determine the distance to 9 nearby stars. We will use this data to calibrate the luminsoity of metal-poor stars which will allow us to obtain accurate distances to metal-poor globular cluster stars with the ultimate goal of determining their ages.

I am a co-investigator of the Hubble Space Telescope Advanced Camera for Surveys Tresury Project on Galactic Globular Clusters. This project has obtained high quality images of 65 galactic globula clusters. One of the higlights of this work was a study of the globular cluster M54, which is located in the center of the Sagittarius dwarf galaxy. The major results of this work are illusrated in the figure below.

My CV in PDF.

Recent papers

Many of my papers are available from the astro-ph pre-print server See the LANL preprint server for my papers over the last 8 years.

Most of my publications are available via ADS

(from ADS Abstract Service)

My favorite Links

My address