Recent Ph.D. graduate Laurin Gray and IU Professor Katherine Rhode have recently published a new paper in The Astrophysical Journal which continues their research on rotation evolution in young, low-mass stars. Their new study focuses on rotation velocities for Sun-like stars in the open clusters IC 5070 (~1 million years old) and IC 348 (~4 million years old). These stars are akin to newborns on stellar timescales. By studying stars in the early stages of their evolution, we can learn more about the processes that helped form our Solar System billions of years ago.
Laurin and her collaborators used high resolution spectra from the WIYN 3.5m telescope to measure rotation velocities for over 150 stars in IC 5070 and IC 348. They combined these measurements with previously published information about the stars to investigate how different characteristics could affect stellar rotation. They found that stars which were interacting with their protoplanetary disks during their first few million years of life may be more likely to rotate slower than stars which lost their disks early on, and that having a binary companion may disrupt this process. They also combined their rotation velocity measurements with rotation periods to estimate the radius of the stars, and compared those estimates to radius predictions from stellar evolution models. They showed that the inclusion of starspots (cooler spots on the surface of stars) in the models can have a significant effect on the predicted properties of the stars, and that models with high starspot coverages (~50%) can still produce reasonable age estimates for star clusters.
Laurin's paper is available now in The Astrophysical Journal: https://iopscience.iop.org/article/10.3847/1538-4357/ae2d04
The College of Arts