Variability of M giant stars based on Kepler photometry: general characteristics
Autor: | A. Bódi, Róbert Szabó, József Benkő, Daniel Huber, O. Shrier, B. Bellamy, Aliz Derekas, Joseph R. Callingham, J. Dorval, Timothy R. Bedding, László L. Kiss, Károly Szatmáry, Gy. M. Szabó, I. Csányi, E. Bányai, Douglas L. Compton, A. E. Simon, Dennis Stello |
---|---|
Jazyk: | angličtina |
Rok vydání: | 2013 |
Předmět: |
media_common.quotation_subject
FOS: Physical sciences Astrophysics 01 natural sciences Photometry (optics) symbols.namesake 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) media_common Physics 010308 nuclear & particles physics Astronomy Astronomy and Astrophysics Light curve Giant star Stars Amplitude Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Fourier analysis Sky symbols Astrophysics::Earth and Planetary Astrophysics Superflare |
Zdroj: | Bányai, E, Kiss, L L, Bedding, T R, Bellamy, B, Benko, J M, Bódi, A, Callingham, J R, Compton, D, Csányi, I, Derekas, A, Dorval, J, Huber, D, Shrier, O, Simon, A E, Stello, D, Szabó, G M, Szabó, R & Szatmáry, K 2013, ' Variability of M giant stars based on Kepler photometry : General characteristics ', Royal Astronomical Society. Monthly Notices, vol. 436, no. 2, pp. 1576-1587 . https://doi.org/10.1093/mnras/stt1685 |
Popis: | M giants are among the longest-period pulsating stars which is why their studies were traditionally restricted to analyses of low-precision visual observations, and more recently, accurate ground-based data. Here we present an overview of M giant variability on a wide range of time-scales (hours to years), based on analysis of thirteen quarters of Kepler long-cadence observations (one point per every 29.4 minutes), with a total time-span of over 1000 days. About two-thirds of the sample stars have been selected from the ASAS-North survey of the Kepler field, with the rest supplemented from a randomly chosen M giant control sample. We first describe the correction of the light curves from different quarters, which was found to be essential. We use Fourier analysis to calculate multiple frequencies for all stars in the sample. Over 50 stars show a relatively strong signal with a period equal to the Kepler-year and a characteristic phase dependence across the whole field-of-view. We interpret this as a so far unidentified systematic effect in the Kepler data. We discuss the presence of regular patterns in the distribution of multiple periodicities and amplitudes. In the period-amplitude plane we find that it is possible to distinguish between solar-like oscillations and larger amplitude pulsations which are characteristic for Mira/SR stars. This may indicate the region of the transition between two types of oscillations as we move upward along the giant branch. 12 pages, 13 figures, accepted for publication in MNRAS. The normalized light curves are available upon request |
Databáze: | OpenAIRE |
Externí odkaz: |