The δ Scuti pulsations of β Pictoris as observed by ASTEP from Antarctica

• Published in: Astronomy & Astrophysics
• Main Authors: Mékarnia, D., Chapellier, E., Guillot, T., Abe, L., Agabi, A., de Pra, Y., Schmider, F. -X., Zwintz, K., Stevenson, K. B., Wang, J. J., Lagrange, A. -M., Bigot, L., Crouzet, N., Fanteï-Caujolle, Y., Christille, J. -M., Kalas, P.
• Other Authors: Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 )-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 )
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: stars: individual: βPictoris; stars: variables: δScuti; stars: oscillations; methods: data analysis; techniques: photometric; Astrophysics - Solar and Stellar Astrophysics; [SDU]Sciences of the Universe [physics]; [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph]; Antarc*; Antarctica
• Online Access: https://insu.hal.science/insu-03692465; https://insu.hal.science/insu-03692465/document; https://insu.hal.science/insu-03692465/file/aa32121-17.pdf; https://doi.org/10.1051/0004-6361/201732121

International audience Aims: The Antarctica Search for Transiting Extrasolar Planets (ASTEP), an automatized 400 mm telescope located at Concordia station in Antarctica, monitored β Pictoris continuously to detect any variability linked to the transit of the Hill sphere of its planet β Pictoris b. The long observation sequence, from March to September 2017, combined with the quality and high level duty cycle of our data, enables us to detect and analyse the δ Scuti pulsations of the star. Methods: Time series photometric data were obtained using aperture photometry by telescope defocussing. The 66 418 data points were analysed using the software package Period04. We only selected frequencies with amplitudes that exceed four times the local noise level in the amplitude spectrum. Results: We detect 31 δ Scuti pulsation frequencies, 28 of which are new detections. All the frequencies detected are in the interval 34.76-75.68 d -1 . We also find that β Pictoris exhibits at least one pulsation mode that varies in amplitude over our monitoring duration of seven months.