The ${\delta}$ Scuti pulsations of ${\beta}$ Pictoris as observed by ASTEP from Antarctica

TL;DR

This study used continuous high-quality photometric data from Antarctica to detect and analyze 31 delta Scuti pulsation frequencies in beta Pictoris, including 28 new detections, revealing amplitude variability over seven months.

Contribution

First detailed analysis of delta Scuti pulsations in beta Pictoris using Antarctic observations, identifying new frequencies and amplitude variations.

Findings

Detected 31 delta Scuti frequencies, 28 of which are new.

Frequencies range from 34.76 to 75.68 d-1.

Observed amplitude variability over seven months.

Abstract

The Antartica Search for Transiting Extrasolar Planets (ASTEP), an automatized 400 mm telescope located at Concordia station in Antarctica, monitored beta Pictoris continuously to detect any variability linked to the transit of the Hill sphere of its planet beta 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 delta Scuti pulsations of the star. 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. We detect 31 delta 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 beta Pictoris exhibits at least one pulsation mode that varies in amplitude over our monitoring duration of seven months.