Rotation and pulsation in Ap stars: first light results from TESS sectors 1 and 2

Abstract

We present the first results from the Transiting Exoplanet Survey Satellite (TESS) on the rotational and pulsational variability of magnetic chemically peculiar A-type stars. We analyse TESS 2-min cadence data from sectors 1 and 2 on a sample of 83 stars. Five new rapidly oscillating Ap (roAp) stars are announced. One of these pulsates with periods around 4.7 min, making it the shortest period roAp star known to date. Four out of the five new roAp stars are multiperiodic. Three of these, and the singly-periodic one show the presence of rotational mode splitting. Individual frequencies are provided in all cases. In addition, seven previously known roAp stars are analysed. Additional modes of oscillation are found in some stars, while in others we are able to distinguish the true pulsations from possible aliases present in the ground-based data. We find that the pulsation amplitude in the TESS filter is typically a factor 6 smaller than that in the $B$ filter which is usually used for ground-based observations. For four roAp stars we set constraints on the inclination angle and magnetic obliquity, through the application of the oblique pulsator model. We also confirm the absence of roAp-type pulsations down to amplitude limits of 6 and 13 micromag, respectively, in two of the best characterised non-oscillating Ap (noAp) stars. We announce 27 new rotational variables along with their rotation periods, and provide different rotation periods for seven other stars. Finally, we discuss how these results challenge state-of-the-art pulsation models for roAp stars.

29 pages, accepted for publication in the MNRAS

References in corpus (23)

• Evolutionary state of magnetic chemically peculiar stars
• Main-Sequence Effective Temperatures from a Revised Mass-Luminosity Relation Based on Accurate Properties
• Chemically peculiar stars and their temperature calibration
• Variability Properties of 4 Million Sources in the $TESS$ Input Catalog Observed with the Kilodegree Extremely Little Telescope Survey
• The role of turbulent pressure as a coherent pulsational driving mechanism: the case of the delta Scuti star HD 187547
• Pulsation tomography of rapidly oscillating Ap stars. Resolving the third dimension in peculiar pulsating stellar atmospheres
• Magnetic OB[A] Stars with TESS: probing their Evolutionary and Rotational properties (MOBSTER) - I. First-light observations of known magnetic B and A stars
• Evolution of magnetic fields in stars across the upper main sequence: I. Catalogue of magnetic field measurements with FORS1 at the VLT
• Isotopic anomaly and stratification of Ca in magnetic Ap stars
• Improved pulsating models of magnetic Ap stars I: exploring different magnetic field configurations
• The fundamental parameters of the roAp star alpha Circini
• New Photometrically Variable Magnetic Chemically Peculiar Stars in the ASAS-3 Archive
• On mode conversion and wave reflection in magnetic Ap stars
• KIC 7582608: A new Kepler roAp star with frequency variability
• Grids of stellar evolution models for asteroseismology (CESAM + POSC)
• Line profile variations in rapidly oscillating Ap stars: resolution of the enigma
• MOST photometry and modeling of the rapidly oscillating (roAp) star gamma Equ
• MOST photometry of the roAp star 10 Aql
• Discovery of pulsational line profile variations in the delta Scuti star HD21190 and in the Ap Sr star HD218994
• A search for rapid pulsations among 9 luminous Ap stars
• Short time-scale frequency and amplitude variations in the pulsations of an roAp star: HD 217522
• A search for rapid pulsations in the magnetic cool chemically peculiar star HD3980
• Time resolved spectroscopy of the cool Ap star HD 213637

Cited by in corpus (30)

• The first view of $\delta$ Scuti and $\gamma$ Doradus stars with the TESS mission
• Gaia Data Release 3: All-sky classification of 12.4 million variable sources into 25 classes
• TESS survey of rotational and pulsational variability of mercury-manganese stars
• Gaia Data Release 3: Cross-match of Gaia sources with variable objects from the literature
• On the first $\delta$ Sct--roAp hybrid pulsator and the stability of p and g modes in chemically peculiar A/F stars
• TESS Cycle 1 observations of roAp stars with 2-min cadence data
• Recipes for bolometric corrections and Gaia luminosities of B-type stars: Application to an asteroseismic sample
• Periodic variable A-F spectral type stars in the northern TESS continuous viewing zone
• Six new rapidly oscillating Ap stars in the Kepler long-cadence data using super-Nyquist asteroseismology
• The Pulsation Properties of $\lambda$ Bootis Stars I. The Southern TESS Sample
• Photometric variability of the LAMOST sample of magnetic chemically peculiar stars as seen by TESS
• Fundamental properties of a selected sample of Ap stars: Inferences from interferometric and asteroseismic constraints
• Long-period Ap stars discovered with TESS data: The northern ecliptic hemisphere
• Unveiling $\delta$ Scuti and $\gamma$ Doradus Hybrid Pulsation of HD 53166 and HD 53349 Plus Rich Frequencies in HD 52788 -- Catalogs of 70552 $\delta$ Sct and 8080 $\gamma$ Dor
• Rapidly-oscillating {\it TESS} A--F main sequence stars: are the roAp stars a distinct class?
• The roAp stars observed by the Kepler Space Telescope
• Rotation signature of TESS B-type stars. A comprehensive analysis
• Space Photometry with BRITE-Constellation
• Variability and stellar pulsation incidence in Am/Fm stars using TESS and Gaia data
• Rotational and pulsational variability in the TESS light curve of HD27463
• Analysis of eight magnetic chemically peculiar stars with rotational modulation
• Discovery of multiple p-mode pulsation frequencies in the roAp star, HD 86181
• Testing ultralow amplitude Cepheid candidates in the Galactic disk by TESS and Gaia
• Pulsation in TESS Objects of Interest
• SALT HRS capabilities for time resolved pulsation analysis: a test with the roAp star $\alpha$ Circini
• EPIC 206197016: A very hot white dwarf orbited by a strongly irradiated red dwarf
• Magnetic field measurements of sharp-lined Ap stars
• Two New roAp Stars Discovered with TESS
• A case study of ACV variables discovered in the Zwicky Transient Facility survey
• A search for transits among the δ Scuti variables in Kepler