000005508 001__ 5508
000005508 005__ 20220914142556.0
000005508 0247_ $$2DOI$$a10.1051/0004-6361/202142921
000005508 037__ $$aSCART-2021-0160
000005508 100__ $$aVan Reeth, T.
000005508 245__ $$aThe near-core rotation of HD112429: a γ Doradus star with TESS photometry and legacy spectroscopy
000005508 260__ $$c2022
000005508 520__ $$aContext. The TESS space mission 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 collect and reduce 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 determine the stellar pulsation frequencies from both data sets using iterative prewhitening, do asymptotic g-mode modelling of the star and investigate the corresponding spectral line profile variations using the pixel-by-pixel method. Results. We validate the pulsation frequencies from the TESS data up 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 Π 0 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.
000005508 594__ $$aNO
000005508 6531_ $$aasteroseismology
000005508 6531_ $$amethods: observational
000005508 6531_ $$astars: variables: general
000005508 6531_ $$astars: oscillations (including pulsations)
000005508 6531_ $$astars: individual: HD11242
000005508 700__ $$aDe Cat, P.
000005508 700__ $$aVan Beeck, J.
000005508 700__ $$aPrat, V.
000005508 700__ $$aWright, D.J.
000005508 700__ $$aLehmann, H.
000005508 700__ $$aChené, A.-N.
000005508 700__ $$aKambe, E.
000005508 700__ $$aYang, S.L.S.
000005508 700__ $$aGentile, G.
000005508 700__ $$aJoos, M.
000005508 773__ $$pAstronomy & Astrophysics$$y2022
000005508 8560_ $$fpeter.decat@observatoire.be
000005508 905__ $$apublished in
000005508 980__ $$aREFERD