Analysis and modeling of high temporal resolution spectroscopic observations of flares on AD Leonis

We report the results of a high temporal resolution spectroscopic monitoring of the flare star AD Leo. During 4 nights, more than 600 spectra were taken in the optical range using the Isaac Newton Telescope (INT) and the Intermediate Dispersion Spectrograph (IDS). We observed a large number of short...

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Detalhes bibliográficos
Autores: Crespo Chacón, I., Montes Gutiérrez, David, García Álvarez, David, Fernández Figueroa, María José, López Santiago, J., Foing, B. H.
Tipo de documento: artigo
Data de publicação:2006
País:España
Recursos:Universidad Complutense de Madrid (UCM)
Repositório:Docta Complutense
Idioma:inglês
OAI Identifier:oai:docta.ucm.es:20.500.14352/51526
Acesso em linha:https://hdl.handle.net/20.500.14352/51526
Access Level:Acceso aberto
Palavra-chave:52
Differential emission measure
Extreme-ultraviolet explorer
White-light flares
Late-type stars
X-ray
Rotational modulation
Stellar flares
XMM-Newton
DME stars
UV ceti
Astrofísica
Astronomía (Física)
Descrição
Resumo:We report the results of a high temporal resolution spectroscopic monitoring of the flare star AD Leo. During 4 nights, more than 600 spectra were taken in the optical range using the Isaac Newton Telescope (INT) and the Intermediate Dispersion Spectrograph (IDS). We observed a large number of short and weak flares occurring very frequently (flare activity > 0.71 h^-1). This is consistent with the very important role that flares can play in stellar coronal heating. The detected flares are non white-light flares and, although most solar flares are of this kind, very few such events have been observed previously in stars. The behaviour of different chromospheric lines (Balmer series from H_α to H_11, Ca II H & K, Na I D_1 and D_2, He I 4026 angstrom and He i D_3) was studied in detail for a total of 14 flares. We estimated the physical parameters of the flaring plasma by using a procedure that assumes a simplified slab model of flares. All the obtained physical parameters are consistent with previously derived values for stellar flares, and the areas - less than 2.3% of the stellar surface - are comparable with the size inferred for other solar and stellar flares. We studied the relationships between the physical parameters and the area, duration, maximum flux and energy released during the detected flares.