Mass and Age Standard Stars - Studying Timing Reliability in Cluster Territory (MASS-STRICT)

San Diego State University Foundation, San Diego CA

Investigators

Abstract

Age is very difficult to determine precisely in astronomy, partly because it is not something that can be directly measured. Stars are the most natural timers to use, and star clusters provide the testing ground for many different age dating methods. This research group will develop selected orbiting multi-star groups in star clusters as precise standards for age dating. The goal is to reduce age uncertainties to under 10% over a huge range, from a youthful 100 million years to 4 billion years, like the Sun. Age measurement is becoming more and more important as larger telescopes allow us to study more distant, fainter stars and to understand their histories. The investigators broader impact plan is centered on addressing the continuing underrepresentation of women and minorities within the physical sciences. The investigator will promote activities at their Hispanic-Serving Institution. They plan active recruitment of minority students (especially early undergraduates), regular academic mentoring and career preparation guidance, and full-year research experiences. Each of these components is important for establishing the flow of students into physical science careers and ultimately making them "normal" choices. Reliable ages are an important ingredient in understanding the workings of stars and the assembly of the Milky Way galaxy. This research will use precise brightness, spectroscopic velocity, and interferometric position measurements of binary stars to infer precise ages, targeting star clusters that are in common use for calibration and testing of the most impactful age measurement techniques. For example, asteroseismology is providing ages for thousands of oscillating red giant stars cutting through the Milky Way, but the technique is currently subject to systematic errors that can be identified and corrected. Ages from the rotation periods of individual main sequence stars require calibration with objects of known age. Ages from cooling white dwarfs depend critically on the ability to predict the initial mass of the star that produced an observed white dwarf and determine its age. But most commonly in astronomy, the brightness and colors of groups of stars are used to estimate age, and this research will examine nearby clusters with the most precise brightness measurements for many members. As a bonus, precisely measured masses will provide an important and long-awaited new dimension for testing models of stars. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.