Tidally trapped pulsations in a close binary star system discovered by TESS
Article
Article Title | Tidally trapped pulsations in a close binary star system discovered by TESS |
---|---|
ERA Journal ID | 213748 |
Article Category | Article |
Authors | Handler, G. (Author), Kurtz, D. W. (Author), Rappaport, S. A. (Author), Saio, H. (Author), Fuller, J. (Author), Jones, D. (Author), Guo, Z. (Author), Chowdhury, S. (Author), Sowicka, P. (Author), Alicavus, F. Kahraman (Author), Streamer, M. (Author), Murphy, S. J. (Author), Gagliano, R. (Author), Jacobs, T. L. (Author) and Vanderburg, A. (Author) |
Journal Title | Nature Astronomy |
Journal Citation | 4 (7), pp. 684-689 |
Number of Pages | 6 |
Year | 2020 |
Publisher | Nature Publishing Group |
Place of Publication | United Kingdom |
ISSN | 2397-3366 |
Digital Object Identifier (DOI) | https://doi.org/10.1038/s41550-020-1035-1 |
Web Address (URL) | https://www.nature.com/articles/s41550-020-1035-1 |
Abstract | It has long been suspected that tidal forces in close binary stars could modify the orientation of the pulsation axis of the constituent stars. Such stars have been searched for, but until now never detected. Here we report the discovery of tidally trapped pulsations in the ellipsoidal variable HD 74423 in Transiting Exoplanet Survey Satellite (TESS) space photometry data. The system contains a δ Scuti pulsator in a 1.6 d orbit, whose pulsation mode amplitude is strongly modulated at the orbital frequency, which can be explained if the pulsations have a much larger amplitude in one hemisphere of the star. We interpret this as an obliquely pulsating distorted dipole oscillation with a pulsation axis aligned with the tidal axis. This is the first time that oblique pulsation along a tidal axis has been recognized. It is unclear whether the pulsations are trapped in the hemisphere directed towards the companion or in the side facing away from it, but future spectral measurements can provide the solution. In the meantime, the single-sided pulsator HD 74423 stands out as the prototype of a new class of obliquely pulsating stars in which the interactions of stellar pulsations and tidal distortion can be studied. |
Keywords | Astrophysics - Solar and Stellar Astrophysics |
ANZSRC Field of Research 2020 | 510109. Stellar astronomy and planetary systems |
Public Notes | Files associated with this item cannot be displayed due to copyright restrictions. |
Institution of Origin | University of Southern Queensland |
Byline Affiliations | Nicolaus Copernicus Astronomical Center, Poland |
University of Central Lancashire, United Kingdom | |
Massachusetts Institute of Technology, United States | |
Tohoku University, Japan | |
California Institute of Technology (Caltech), United States | |
Institute of Astrophysics of the Canary Islands, Spain | |
Pennsylvania State University, United States | |
Polish Academy of Sciences, Poland | |
Australian National University | |
University of Sydney | |
Yale University, United States | |
No affiliation | |
University of Texas at Austin, United States |
https://research.usq.edu.au/item/q7383/tidally-trapped-pulsations-in-a-close-binary-star-system-discovered-by-tess
71
total views4
total downloads1
views this month0
downloads this month