Diego Godoy-Rivera
Research Interests
Research Interests
Gyrochronology and Stellar Rotation
Together with mass and composition, rotation is one of the fundamental properties of stars. Rotation has been proposed as a proxy for age, one of the most important but difficult to measure stellar properties. This idea is known as gyrochronology, and it could help us better understand stars and their exoplanets. My research focuses on exploring the evolution of stellar rotation as a function of age, and studying its dependences with stellar mass, composition, activity, binarity, and others. Some of the projects I have carried out to explore this are described below. |
1) Open Clusters
To first order, open clusters are group of stars that were born together and that share the same chemical composition. Therefore, they offer snapshots of the evolution of stellar rotation at specific ages and metallicities. In my research I am taking advantage of the exquisite photometric monitoring of several open clusters (from both the ground and space, e.g., Kepler and K2), in combination with astrometric data from the Gaia mission, in order to clean their memberships (i.e., I am removing the non-member contamination). My goal is to obtain an updated view of stellar rotation (as a function of mass, age, composition), which can be used to place stringent constraints on the physical processes that regulate its evolution. For more details, please check out our paper: Godoy-Rivera, Pinsonneault & Rebull (2021). |
2) Subgiant Stars
Once the hydrogen-burning stops in their core, stars leave the main-sequence and go through the subgiant phase before ascending onto the red giant branch. Given their intermediate stage of evolution, subgiant stars can place interesting constraints on several open questions in astrophysics (e.g., the existence of a common dynamo mechanism across different evolutionary stages, mixing processes in stellar interiors, the occurrence rates of exoplanets as a function of stellar mass). My research has focused on a thorough and systematic characterization of subgiants that have been and are being observed by the TESS mission. I have used uniform and precise photometric, astrometric, and spectroscopic data from Gaia and APOGEE to effectively test the limits of how precisely we can characterize subgiant stars. Among my results, I have found a correlation that supports the rotation-activity connection in post-MS stars. For more details, please check out our paper: Godoy-Rivera, Tayar, Pinsonneault, et al. (2021). |
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3) Wide Binaries
Unlike our Sun, most stars in the universe have companions, and we classify those with semi-major axes greater than ~ 100 AU as "wide" binaries. A helpful way of thinking about them is as the tiniest versions of open clusters. In my research I have use astrometric information to identify a sample of bona-fide wide binaries in the Kepler field, a field with ~ 200,00 stars photometrically monitored for ~ 4 years by the Kepler mission, and that could therefore have rotation period measurements. I have used these binary stars to explore the behavior of stellar rotation in co-eval systems, finding that their rotation rates often show discrepancies compared with the expectations. For more details, please check out our paper: Godoy-Rivera & Chanamé (2018). |
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