STRW local: Lunch Talks

Lunch Talks

Age-relations for low-mass stars [N.B.: starts at 13:00!]

Stellar age is a key fundamental property for understanding the history, evolution, and future of stellar populations, the Milky Way, and exoplanets. However, age is extremely difficult to measure for individual stars. Low-mass stars, or M dwarfs, are the most numerous stars in the Galaxy, they have lifetimes longer than the current age of the Universe, and are likely to host the majority of Earth-like exoplanets. For this reason, these main sequence stars are ideal for studying the Milky Way and exoplanets properties in a wide range of ages. Ages of M dwarfs are especially difficult to estimate because methods used for solar-type stars break down as lower mass objects become fully convective. Empirical and statistical methods are required to constrain the ages of M dwarfs. I want to build a robust Bayesian algorithm to infer ages of M dwarfs from the following age indicators: 1) Position in the color-magnitude diagram; 2) Magnetic activity, as indicated by the H-alpha emission line; 3) Full kinematics, taking advantage of Gaia DR2 and DR3; 4) Rotation periods. I will present the age-calibrations I did of these age indicators, including the age-activity relation for the H𝛼 emission line. I will show the results I obtained from the calibration of the age-activity relation, which indicates that H-alpha equivalent widths decrease with age. I will also explain how I am going to use this relation to obtain precise estimation of M dwarf ages.


Unless announced otherwise, the lunch talks start at 12:50 sharp. The approximate duration of the lunch talk is given above, and additional time will be given for questions and discussion following the presentation. Please make sure that you take ample time to pick up your lunch beforehand.

Information for Speakers and Hosts: Talks are limited to 25 minutes, with 5 additional minutes for questions. Hosts are responsible for bringing the speaker to the correct room in ample time to set up laptops etc., and for ensuring the speaker also has time for lunch.

For questions and/or suggestions concerning the lunch talks, please contact Peter Mitchell () or Yannick Bahe ().