Triggers:Flares

• Statistical study of M dwarf flares in Stripe 82 is presented in Kowalski et al. 2009.

• Colour range for M-dwarfs (r − i) > 0.53 and (i − z) > 0.3 and (u-r) > 3
• flares are the most pronounced in u-band
• around 35% of M-dwarfs are in binary systems - these have bluer u-g. Most single M-dwarfs will have u-g > 1.8
• g - K > 4
• amplitude in u > 0.7 mag up to 5 mag.
• flaring fraction: 0.0108%, i.e. 1 of every 10,000 observation of a M-dwarf in Stripe 82 resulted in a flare
• 1.3 flares per hour sq.deg with $\Deta u > 0.7$ mag, with slightly more flares towards the galactic plane.

Example of flares in Gl234AB (V577 Mon) from Doyle et al. 1989