Rotational Variability in the TESS Light Curve of 21 Com
We present an analysis of the TESS-based light curve of the chemically peculiar A-type (Ap) star 21 Com (HD 108945). We used the simple aperture photometry light curve with a time span of 27 days. A least-squares fit to the data with 10 harmonics yields a frequency of 0.48726 day-1, which corresponds to a rotational period of 2.05229 days. Furthermore, we find no evidence of any short-term variability beyond the pure rotational signature.