The Great Flare of 1985 April 12 on AD Leonis
Abstract
A giant flare on the M dwarf star AD Leo is examined on the basis of photometric and spectroscopic observations covering the wavelength range 1200-1800 A. A flare energy budget over the entire optical and ultraviolet wavelength region is constructed as a function of time during the flare. The continuum radiation is shown to be the dominant source of energy loss during both the initial 'impulsive' phase and the later 'gradual' phase. The emission lines contribute less than 10 percent of the total flare energy in this wavelength region but are about four times more important during the gradual phase than in the impulsive phase. The energy budget is compared with another, less energetic, flare on AD Leo and found to be quite similar. The relationships between the integrated properties of several flare emission features are investigated. Good correlation between H-gamma and Ca II K emission, and H-gamma and U filter emission is found. It is inferred from these correlations that the observed emission features are produced under similar atmospheric conditions regardless of the total flare energy emitted.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1991
- DOI:
- 10.1086/170474
- Bibcode:
- 1991ApJ...378..725H
- Keywords:
-
- Dwarf Stars;
- Stellar Atmospheres;
- Stellar Flares;
- Stellar Spectra;
- Ultraviolet Spectra;
- Astronomical Photometry;
- Astronomical Spectroscopy;
- Emission Spectra;
- Energy Budgets;
- Line Spectra;
- Wavelengths;
- Astrophysics;
- STARS: FLARE;
- STARS: INDIVIDUAL CONSTELLATION NAME: AD LEONIS;
- ULTRAVIOLET: SPECTRA