Possible chromospheric activity cycles in AD Leo

Abstract

AD Leo (GJ 388) is an active dM3 flare star extensively observed both in the quiescent and flaring states. Since this active star is near the fully-convective boundary, to study in detail its long-term chromospheric activity could be an appreciable contribution for the dynamo theory. Here, we analyze with the Lomb-Scargle periodogram the Ca II K line-core fluxes derived from CASLEO spectra obtained between 2001 and 2013 and the V magnitude from the ASAS database between 2004 and 2010. From both totally independent time-series, we obtain a possible activity cycle of period $\sim 7$ years and a less-significant shorter one of $\sim 2$ years. A tentative interpretation is that a dynamo operating near the surface could be generating the longer cycle, while a second dynamo operating in the deep convection zone could be responsible for the shorter one. Based on the long duration of our observing program at CASLEO and the fact that we observe simultaneously different spectral features, we also analyze the relation between simultaneous measurements of the Na I index ($R_D^{\prime }$), H$\alpha$ and Ca II K fluxes at different activity levels of AD Leo, including flares.

21 pages, 3 figures.Accepted for publication in ApJL

References in corpus (12)

• Simulations of dynamo action in fully convective stars
• The First Direct Measurements of Magnetic Fields on Very Low-Mass Stars
• Fluxes in Hαand Ca II H and K for a sample of Southern stars
• Sun-as-a-Star Spectrum Variations 1974-2006
• Magnetic Activity Cycles in the Exoplanet Host Star epsilon Eridani
• Tracers of Chromospheric Structure I: Observations of Ca II K and H alpha in M Dwarfs
• The Na I D resonance lines in main sequence late-type stars
• Analysis and modeling of high temporal resolution spectroscopic observations of flares on AD Leo
• A possible activity cycle in Proxima Centauri
• Mg II h + k emission lines as stellar activity indicators of main sequence F-K stars
• Long-term chromospheric activity of non-eclipsing RS CVn-type stars
• The spectroscopic binary system Gl 375. I. Orbital parameters and chromospheric activity

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• Keplerian periodogram for Doppler exoplanets detection: optimized computation and analytic significance thresholds
• The CARMENES search for exoplanets around M dwarfs. Variability on long timescales as seen in chromospheric indicators
• Ross 128 -- GL 447A possible activity cycle for a slow-rotating fully-convective star
• Photometric observations of flares on AD Leo from GWAC-F30 and TESS
• Correlation between activity indicators: H$\alpha$ and Ca II lines in M-dwarf stars
• The GAPS programme at TNG XXVI. Magnetic activity in M stars: spectroscopic monitoring of AD Leonis
• An application of a solar-type dynamo model for Epsilon Eridani
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