2005/12/07 by B. Rockenfeller, Boris Rockenfeller, C. A. L. Bailer-Jones +5 · 4 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Pulsars and Gravitational Waves Research #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2006.09961.x
published as Mon.Not.Roy.Astron.Soc.367:407-411,2006 · Accepted to MNRAS. Five pages
arxiv created 2005/12/07 · openalex publication_date 2006/03/07 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We present simultaneous UV, G, R and I monitoring of 19 M dwarfs that reveal a huge flare on the M9 dwarf with an amplitude in the UV of at least 6 mag. This is one of the strongest detections ever of an optical flare in an M star and one of the first in an ultracool dwarf (spectral types later than about M7). Four intermediate-strength flares (ΔmUV < 4 mag) were found in this and three other targets. For the whole sample we deduce a flare probability of 0.013 (rate of 0.022 h−1), and 0.049 (0.090 h−1) for 2M1707+64 alone. Deviations of the flare emission from a blackbody is consistent with strong Hα line emission. We also confirm our previously found rotation period for 2M1707+64 and determine it more precisely to be 3.619 ± 0.015 h.