Image Details
Caption: Figure 6.
Rotation period vs. dereddened Gaia color for NGC 6819 and Ruprecht 147 (cyan; J. L. Curtis et al. 2020). Data sources for NGC 6819 include this work (magenta), S. Meibom et al. (2015) (purple), and S. Sanjayan et al. (2022) (gray). Background shading indicates spectral type, as described in Figure 5.
© 2026. The Author(s). Published by the American Astronomical Society.