A study of pulsation & rotation in a sample of A-K type stars in the Kepler field

Sowgata Chowdhury, Santosh Joshi, Chris A. Engelbrecht, Peter De Cat, Yogesh C. Joshi, K. T. Paul

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)

Abstract

We present the results of time-series photometric analysis of 15106 A-K type stars observed by the Kepler space mission. We identified 513 new rotational variables and measured their starspot rotation periods as a function of spectral type and discuss the distribution of their amplitudes. We examined the well-established period-color relationship that applies to stars of spectral types F5-K for all of these rotational variables and, interestingly, found that a similar period-color relationship appears to extend to stars of spectral types A7 to early-F too. This result is not consistent with the very foundation of the period-color relationship. We have characterized 350 new non-radial pulsating variables such as A- and F-type candidate δ Scuti, γ Doradus and hybrid stars, which increases the known candidate non-radial pulsators in the Kepler field significantly, by ∼20%. The relationship between two recently constructed observables, Energy and Efficiency, was also studied for the large sample of non-radial pulsators, which shows that the distribution in the logarithm of Energy (log (En)) can be used as a potential tool to distinguish between the non-radial pulsators, to some extent. Through visual inspection of the light curves and their corresponding frequency spectra, we found 23 new candidate red giant solar-like oscillators not previously reported in the literature. The basic physical parameters such as masses, radii and luminosities of these solar-like oscillators were also derived using asteroseismic relations.

Original languageEnglish
Article number260
JournalAstrophysics and Space Science
Volume363
Issue number12
DOIs
Publication statusPublished - 1 Dec 2018

Keywords

  • Stars: oscillations
  • Stars: rotation, starspots
  • Stars: variables
  • Stars: variables: solarlike
  • Stars: variables: δ Scuti

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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