The near-core rotation of HD 112429 A γ Doradus star with TESS photometry and legacy spectroscopy
Article
Article Title | The near-core rotation of HD 112429 A γ Doradus star with TESS photometry and legacy spectroscopy |
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ERA Journal ID | 1050 |
Article Category | Article |
Authors | Van Reeth, T., De Cat, P., Van Beeck, J., Prat, V., Wright, D.J., Lehmann, H., Chené, A.-N., Kambe, E., Yang, S. L. S., Gentile, G. and Joos, M. |
Journal Title | Astronomy and Astrophysics: a European journal |
Journal Citation | 662 |
Article Number | A58 |
Number of Pages | 15 |
Year | 2022 |
Publisher | EDP Sciences |
Place of Publication | France |
ISSN | 0004-6361 |
1432-0746 | |
Digital Object Identifier (DOI) | https://doi.org/10.1051/0004-6361/202142921 |
Web Address (URL) | https://www.aanda.org/articles/aa/full_html/2022/06/aa42921-21/aa42921-21.html |
Abstract | Context. The Transiting Exoplanet Survey Satellite (TESS) provides us with high-precision photometric observations of large numbers of bright stars over more than 70% of the entire sky, allowing us to revisit and characterise well-known stars. Aims. We aim to conduct an asteroseismic analysis of the γ Doradus (γ Dor) star HD 112429 using both the available ground-based spectroscopy and TESS photometry, and assess the conditions required to measure the near-core rotation rate and buoyancy travel time. Methods. We collected and reduced the available five sectors of short-cadence TESS photometry of this star, as well as 672 legacy observations from six medium- to high-resolution ground-based spectrographs. We determined the stellar pulsation frequencies from both data sets using iterative prewhitening, did asymptotic g mode modelling of the star, and investigated the corresponding spectral line profile variations using the pixel-by-pixel method. Results. We validate the pulsation frequencies from the TESS data down to S/N ≥ 5.6, confirming recent reports in the literature that the classical criterion S/N ≥ 4 does not suffice for space-based observations. We identify the pulsations as prograde dipole g modes and r-mode pulsations, and measure a near-core rotation rate of 1.536 (3) d−1 and a buoyancy travel time Π0 of 4190 (50) s. These results are in agreement with the observed spectral line profile variations, which were qualitatively evaluated using a newly developed toy model. We establish a set of conditions that have to be fulfilled for an asymptotic asteroseismic analysis of g-mode pulsators. In the case of HD 112429, two TESS sectors of space photometry suffice. Conclusions. Although a detailed asteroseismic modelling analysis is not viable for g-mode pulsators with only short or sparse light curves of space photometry, it is possible to determine global asteroseismic quantities for a subset of these stars. Thanks to the ongoing TESS mission, this will allow us to characterise many more stars than only those with years of data. |
Keywords | asteroseismology – methods; observational – stars; variables; general – stars; oscillations – stars; individual; HD112429 |
ANZSRC Field of Research 2020 | 5101. Astronomical sciences |
Public Notes | Files associated with this item cannot be displayed due to copyright restrictions, but may be accessed online. Please see the link in the URL field. |
Byline Affiliations | Institute of Astronomy, Belgium |
Royal Observatory of Belgium | |
California Institute of Technology (Caltech), United States | |
Paris-Saclay University, France | |
Centre for Astrophysics | |
Karl Schwarzschild Observatory, Germany | |
Gemini Observatory, United States | |
National Astronomical Observatory of Japan, Japan | |
University of Victoria, Canada | |
University of Gent, Belgium | |
Vrije University Brussels, Belgium | |
CEA / DAM / DIF, France |
https://research.usq.edu.au/item/z02x6/the-near-core-rotation-of-hd-112429-a-doradus-star-with-tess-photometry-and-legacy-spectroscopy
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