RT journal article
T1 Gaia Data Release 3: Pulsations in main sequence OBAF-type stars
A1 De Ridder, J.
A1 Ripepi, V.
A1 Aerts, C.
A1 Palaversa, L.
A1 Eyer, L.
A1 Berihuete Macías, Ángel
A2 Estadística e Investigación Operativa
K1 asteroseismology
K1 stars: rotation
K1 stars: oscillations
K1 stars: early-type
AB Context. The third Gaia data release provides photometric time series covering 34 months for about 10 million stars. For many of those stars,a characterisation in Fourier space and their variability classification are also provided. This paper focuses on intermediate- to high-mass (IHM)main sequence pulsators (M ≥ 1.3 M ) of spectral types O, B, A, or F, known as βCep, slowly pulsating B (SPB), δ Sct, and γ Dor stars. Thesestars are often multi-periodic and display low amplitudes, making them challenging targets to analyse with sparse time series.Aims. We investigate the extent to which the sparse Gaia DR3 data can be used to detect OBAF-type pulsators and discriminate them from othertypes of variables. We aim to probe the empirical instability strips and compare them with theoretical predictions. The most populated variabilityclass is that of the δ Sct variables. For these stars, we aim to confirm their empirical period-luminosity (PL) relation, and verify the relation betweentheir oscillation amplitude and rotation.Methods. All datasets used in this analysis are part of the Gaia DR3 data release. The photometric time series were used to perform a Fourieranalysis, while the global astrophysical parameters necessary for the empirical instability strips were taken from the Gaia DR3 gspphot tables,and the v sin i data were taken from the Gaia DR3 esphs tables. The δ Sct PL relation was derived using the same photometric parallax method asthe one recently used to establish the PL relation for classical Cepheids using Gaia data.Results. We show that for nearby OBAF-type pulsators, the Gaia DR3 data are precise and accurate enough to pinpoint them in the HertzsprungRussell (HR) diagram. We find empirical instability strips covering broader regions than theoretically predicted. In particular, our study reveals thepresence of fast rotating gravity-mode pulsators outside the strips, as well as the co-existence of rotationally modulated variables inside the stripsas reported before in the literature. We derive an extensive period–luminosity relation for δ Sct stars and provide evidence that the relation featuresdifferent regimes depending on the oscillation period. We demonstrate how stellar rotation attenuates the amplitude of the dominant oscillationmode of δ Sct stars.Conclusions. The Gaia DR3 time-series photometry already allows for the detection of the dominant (non-)radial oscillation mode in about 100 000 intermediate- and high-mass dwarfs across the entire sky. This detection capability will increase as the time series becomes longer,allowing the additional delivery of frequencies and amplitudes of secondary pulsation modes.
PB EDP Sciences
SN 1432-0746
YR 2022
FD 2022-05-24
LK http://hdl.handle.net/10498/32139
UL http://hdl.handle.net/10498/32139
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 11-nov-2026