Periodic Low Amplitude Variations in the Brightness of Proxima Centauri
Benedict, G. F.; Franz, O. G.; Hemenway, P. D.; Jefferys, W. H.; McArthur, B.; Nelan, E.; Shelus, P. J.; Story, D.; Whipple, A. L.; Duncombe, R. L.; Fredrick, L. W.; van Altena, W.; Ting-Gao, Yang
United States, China
Abstract
Using data acquired with Fine Guidance Sensor #3 on board the Hubble Space Telescope we find that the brightness of Proxima Centauri varies with an amplitude of 0.01 magnitude and a period P=41.6 +/- 0.6 days. We interpret this variation as rotational modulation of star spots or bright regions in the photosphere of Proxima Centauri. In a total of 89.36 minutes of monitoring over 212 days, we detected one major flare and three post-flare brightenings. (SECTION: Stars)