M dwarf flares Archives

Illustration of flare heating in three types of stars. The dashed line marks the stellar surface; blue areas show the quiet atmosphere, and red areas show regions heated during a white-light flare. Vertical arrows indicate the radiative output, with length proportional to intensity. In solar-like stars (left), heating is regulated by hydrogen ionization, which limits temperatures of white-light flares to ∼ 9000 K. In late M dwarfs like TRAPPIST-1 (middle), molecular hydrogen dissociation acts as a thermostat, capping temperatures of white-light flares near ∼ 3500 − 4000 K. In early M dwarfs (right), insufficient concentration of H2 means the dissociation thermostat is ineffective, allowing higher white-light flare temperatures. -- astro-ph.SR

Exoplanets, -moons, -comets, Radiation, Space Weather & Heliophysics, Status Report, TRAPPIST-1

Molecular Hydrogen Controls The Temperatures Of Flares On TRAPPIST-1

by Keith CowingJanuary 6, 2026January 6, 2026

Early JWST observations of TRAPPIST-1 have revealed an unexpected puzzle: energetic white-light flares (E>1030 erg) reach temperatures of only ∼3500–4000,K, nearly three times cooler than typical solar flares, which peak […]

Comparison of bolometric energies and durations of NUV (blue crosses) and optical (red dots) M dwarf flares from this work with those of solar and stellar flares observed with SDO/HMI (black solid stars; Namekata et al. 2017), GALEX (black astericks; Brasseur et al. 2019), DEC (solid diamonds; Webb et al. 2021) and Kepler (open triangles and open squares; Shibayama et al. 2013; Maehara et al. 2015). The cadence sizes are 45 s, 10 s, 20 s, and 1 or 30 min, respectively. The dashed and dotted lines correspond to scaling laws between flare durations and energies corresponding to either constant magnetic field (B) with varying emitting region length scale (L) or constant emitting region length scale with varying magnetic field. -- astro-ph.SR

Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Habitable Zones, Radiation, Space Weather & Heliophysics, Status Report

A Multiwavelength Survey of Nearby M dwarfs: Optical and Near-Ultraviolet Flares and Activity with Contemporaneous TESS, Kepler/K2, Swift, and HST Observations

by Keith CowingApril 19, 2024April 19, 2024

We present a comprehensive multiwavelength investigation into flares and activity in nearby M~dwarf stars. We leverage the most extensive contemporaneous dataset obtained through the Transiting Exoplanet Sky Survey (TESS), Kepler/K2, […]

M dwarf flares

Molecular Hydrogen Controls The Temperatures Of Flares On TRAPPIST-1

A Multiwavelength Survey of Nearby M dwarfs: Optical and Near-Ultraviolet Flares and Activity with Contemporaneous TESS, Kepler/K2, Swift, and HST Observations

Tricorder Tech: New Handheld Device Maps Chemical Composition Using Infrared Light

No Statistically Significant Evidence For A Correlation Between Stellar And planetary Composition

Water Planet Recon: How Accurately Can We Measure Earth Ocean’s Deepest Point?

Webb Reveals A Stunning Panorama Of Star Formation

Deep Learning of SHERLOC Raman Spectra For Facilitating Mars Astromaterial Identification