Search for GeV Gamma-Ray Emission from Possible TeV-bright Red Dwarfs with Fermi-LAT

Abstract

Red dwarfs have been suggested to be among the possible astrophysical species accelerating particles and emitting TeV γ-rays. In an effort to search for the GeV γ-ray counterparts of the suggested TeV emission from eight red dwarfs, we analyze the 0.2–500 GeV γ-ray emission of the regions covering them, exploiting the ∼13.6 yr Pass 8 data from the Fermi Large Area Telescope (LAT). A GeV γ-ray emission excess with a significance of 3.8σ is detected in the direction of the red dwarf V962 Tau. This emission contains V962 Tau in a 1σ error radius and is independent of the catalog source. However, the stellar flare scenario can hardly explain the total energy and lightcurve (LC) derived from the γ-ray emission in view of the spectral analysis. We also analyze the LCs in the positions of the eight red dwarfs, and no time bin with a significance >5σ is found. Therefore, no significant emission from the red dwarfs could be concluded to have been detected by Fermi-LAT.