Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Gaia Data Release 3: Pulsations in main sequence OBAF-type stars

De Ridder, J. ; Lindegren, L. LU orcid ; Hobbs, D. LU orcid ; McMillan, P.J. LU orcid ; Zucker, S. and Zwitter, T. (2023) In Astronomy and Astrophysics 674.
Abstract
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'a ¥''1.3'M') of spectral types O, B, A, or F, known as β Cep, slowly pulsating B (SPB), δ Sct, and γ Dor stars. These stars 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 other types of variables. We aim to probe the... (More)
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'a ¥''1.3'M') of spectral types O, B, A, or F, known as β Cep, slowly pulsating B (SPB), δ Sct, and γ Dor stars. These stars 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 other types of variables. We aim to probe the empirical instability strips and compare them with theoretical predictions. The most populated variability class is that of the δ Sct variables. For these stars, we aim to confirm their empirical period-luminosity (PL) relation, and verify the relation between their 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 Fourier analysis, 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 as the 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 Hertzsprung-Russell (HR) diagram. We find empirical instability strips covering broader regions than theoretically predicted. In particular, our study reveals the presence of fast rotating gravity-mode pulsators outside the strips, as well as the co-existence of rotationally modulated variables inside the strips as reported before in the literature. We derive an extensive period'luminosity relation for δ Sct stars and provide evidence that the relation features different regimes depending on the oscillation period. We demonstrate how stellar rotation attenuates the amplitude of the dominant oscillation mode 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. © 2023 EDP Sciences. All rights reserved. (Less)
Please use this url to cite or link to this publication:
author
; ; ; ; and
author collaboration
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Asteroseismology, Stars: early-type, Stars: oscillations, Stars: rotation, Astrophysics, Fourier analysis, Fourier series, Geometrical optics, Luminance, Rotation, Stability, Time series, Time series analysis, Data release, Fourier space, Oscillation mode, Period-luminosity relations, Photometrics, Star oscillations, Stars: Rotation, Stars:early type, Times series, Stars
in
Astronomy and Astrophysics
volume
674
article number
A36
publisher
EDP Sciences
external identifiers
  • scopus:85164247115
ISSN
0004-6361
DOI
10.1051/0004-6361/202243767
language
English
LU publication?
yes
id
72be79bd-08b6-4e37-9a52-2685b97699de
date added to LUP
2024-01-16 14:14:17
date last changed
2024-04-16 22:40:23
@article{72be79bd-08b6-4e37-9a52-2685b97699de,
  abstract     = {{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'a ¥''1.3'M') of spectral types O, B, A, or F, known as β Cep, slowly pulsating B (SPB), δ Sct, and γ Dor stars. These stars 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 other types of variables. We aim to probe the empirical instability strips and compare them with theoretical predictions. The most populated variability class is that of the δ Sct variables. For these stars, we aim to confirm their empirical period-luminosity (PL) relation, and verify the relation between their 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 Fourier analysis, 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 as the 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 Hertzsprung-Russell (HR) diagram. We find empirical instability strips covering broader regions than theoretically predicted. In particular, our study reveals the presence of fast rotating gravity-mode pulsators outside the strips, as well as the co-existence of rotationally modulated variables inside the strips as reported before in the literature. We derive an extensive period'luminosity relation for δ Sct stars and provide evidence that the relation features different regimes depending on the oscillation period. We demonstrate how stellar rotation attenuates the amplitude of the dominant oscillation mode 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. © 2023 EDP Sciences. All rights reserved.}},
  author       = {{De Ridder, J. and Lindegren, L. and Hobbs, D. and McMillan, P.J. and Zucker, S. and Zwitter, T.}},
  issn         = {{0004-6361}},
  keywords     = {{Asteroseismology; Stars: early-type; Stars: oscillations; Stars: rotation; Astrophysics; Fourier analysis; Fourier series; Geometrical optics; Luminance; Rotation; Stability; Time series; Time series analysis; Data release; Fourier space; Oscillation mode; Period-luminosity relations; Photometrics; Star oscillations; Stars: Rotation; Stars:early type; Times series; Stars}},
  language     = {{eng}},
  publisher    = {{EDP Sciences}},
  series       = {{Astronomy and Astrophysics}},
  title        = {{Gaia Data Release 3: Pulsations in main sequence OBAF-type stars}},
  url          = {{http://dx.doi.org/10.1051/0004-6361/202243767}},
  doi          = {{10.1051/0004-6361/202243767}},
  volume       = {{674}},
  year         = {{2023}},
}