Kepler Flares III: Stellar Activity on GJ 1245 A and B
| Autor: | J. C. Lurie, Adam F. Kowalski, John P. Wisniewski, James R. A. Davenport, Leslie Hebb, Suzanne L. Hawley, Tessa D. Wilkinson |
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| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Physics
Angular distance Starspot FOS: Physical sciences Astronomy and Astrophysics Context (language use) Astrophysics Light curve law.invention Orbit Stars Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science law Differential rotation Solar and Stellar Astrophysics (astro-ph.SR) Flare |
| Popis: | We present the flare occurrence rates and starspot evolution for GJ 1245 A and B, two active M5 stars, based on nine months of Kepler short cadence observations, and four years of nearly continuous long cadence observations. The A component is separated from the B component by 7 arcseconds, and the stars are not resolved in the Kepler pipeline processing due to Kepler's large plate scale of 4 arcseconds/pixel. Analyzing the target pixel data, we have generated separate light curves for components A and B using the PyKE pixel response function modeling procedures, and note the effects of CCD saturation and non-linear response to high energy flares. In our sample, GJ 1245A and B exhibit an average of 3.0 and 2.6 flares per day, respectively. We introduce a new metric, $L_{fl}/L_{\mathrm{Kp}}$, to compare the flare rates between stars, and discuss this in the context of GJ 1245 A and B. Both stars exhibit starspot features that evolve on long time scales, with the slower rotating B component showing evidence of differential rotation. Intriguingly, the angular separation between the A and B component photocenters decreases during the four years of observations in a manner consistent with a shift in the position of the A photocenter due to the orbit of its unseen M8 companion (GJ 1245C), which is $\sim$94% less bright. Among the most detailed photometric studies of fully convective M dwarfs in a multiple system, these results provide an important constraint on stellar age-rotation-activity models. 15 pages, 10 figures, 2 tables. Accepted to ApJ |
| Databáze: | OpenAIRE |
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