Characteristic time of stellar flares on Proxima Centauri

Abstract

Proxima Centauri is a flare productive M5.5 main-sequence star. Its flares have been observed in a 20-second light-curve cadence by the TESS satellite during Sector 38 of the mission. We conduct a statistical analysis of the characteristic time of Proxima flares using the 20-second cadence light-curve data collected by TESS. The durations of flare rise phase and decay phase are analyzed separately for the flares of Proxima found in the TESS light curve. The result shows that the time scales of the flare rise phase and decay phase of Proxima are 0.53 ± 0.17 minutes and 7.0 ± 1.9 minutes, respectively, which are much shorter than those of Sun-like stars. The implication of the result on the magnetic field environment of the flare source regions on Proxima is discussed.