Photometric variability of the LAMOST sample of magnetic chemically peculiar stars as seen by TESS

Abstract

High-quality light curves from space missions have opened up a new window on the rotational and pulsational properties of magnetic chemically peculiar (mCP) stars and have fuelled asteroseismic studies. They allow the internal effects of surface magnetic fields to be probed and numerous astrophysical parameters to be derived with great precision. We present an investigation of the photometric variability of a sample of 1002 mCP stars discovered in the LAMOST archival spectra with the aims of measuring their rotational periods and identifying interesting objects for follow-up studies. TESS photometry was available for 782 mCP stars and was analysed using a Fourier two-term frequency fit to determine the stars' rotational periods. The rotational signal was then subtracted from the light curve to identify non-rotational variability. A pixel-level blending analysis was performed to check whether the variability originates in the target star or a nearby blended neighbour. We investigated correlations between the rotational periods, fractional age on the main sequence, mass, and several other observables. We present rotational periods and period estimates for 720 mCP stars. In addition, we identified four eclipsing binary systems that likely host an mCP star, as well as 25 stars with additional signals consistent with pulsation (12 stars with frequencies above 10 d${}^{-1}$ and 13 stars with frequencies below 10 ${}^{-1}$). We find that more evolved stars have longer rotation periods, in agreement with the assumption of the conservation of angular momentum during main-sequence evolution. With our work, we increase the sample size of mCP stars with known rotation periods and identify prime candidates for detailed follow-up studies. This enables two paths towards future investigations: population studies of even larger samples of mCP stars and the detailed characterisation of high-value targets.

arXiv comment30 pages, 9 figures, 1 table. Accepted for publication in the Journal of Astronomy and Astrophysics (A&A)

References in corpus (57)

• Astropy: A Community Python Package for Astronomy
• The Gaia mission
• Gaia Data Release 3: Summary of the content and survey properties
• The Transiting Exoplanet Survey Satellite
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• The VizieR database of Astronomical Catalogues
• The Revised TESS Input Catalog and Candidate Target List
• A fossil origin for the magnetic fields of A-stars and white dwarfs
• Weak magnetic fields in Ap/Bp stars: Evidence for a dipole field lower limit and a tentative interpretation of the magnetic dichotomy
• Introduction to astroML: Machine Learning for Astrophysics
• How mergers magnetise massive stars
• Periodograms for Multiband Astronomical Time Series
• Gamma Doradus Stars: Defining a New Class of Pulsating Variables
• Evolutionary state of magnetic chemically peculiar stars
• Gaia Data Release 3: Catalogue Validation
• A unifying explanation of complex frequency spectra of gamma Dor, SPB and Be stars: combination frequencies and highly non-sinusoidal light curves
• Photometric detection of internal gravity waves in upper main-sequence stars. II. Combined TESS photometry and high-resolution spectroscopy
• The Magnetic Early B-type Stars III: A main sequence magnetic, rotational, and magnetospheric biography
• On the photometric detection of Internal Gravity Waves in upper main-sequence stars I. Methodology and application to CoRoT targets
• Forward seismic modelling of the pulsating magnetic B-type star HD 43317
• A Volume Limited Survey of mCP Stars Within 100pc II: Rotational and Magnetic Properties
• Multisite spectroscopic seismic study of the beta Cep star V2052 Oph: inhibition of mixing by its magnetic field
• An Investigation of the Rotational Properties of Magnetic Chemically Peculiar Stars
• New catalogue of Chemically Peculiar stars, and Statistical Analysis
• A photometric study of chemically peculiar stars with the STEREO satellites. I. Magnetic chemically peculiar stars
• MOBSTER - II. Identification of rotationally variable A stars observed with \emph{TESS} in Sectors 1 to 4
• On the detection of chemically peculiar stars using Delta a photometry
• Kepler observations of a roAp star: delta Scuti and gamma Doradus pulsations in Ap stars
• Rotation and pulsation in Ap stars: first light results from TESS sectors 1 and 2
• Magnetic OB[A] Stars with TESS: probing their Evolutionary and Rotational properties (MOBSTER) - I. First-light observations of known magnetic B and A stars
• An all-sky sample of intermediate- to high-mass OBA-type eclipsing binaries observed by TESS
• Magnetic fields of HgMn stars
• Gaia's view of the $\lambda$ Boo star puzzle
• K2 space photometry reveals rotational modulation and stellar pulsations in chemically peculiar A and B stars
• Modelling the light variability of the Ap star epsilon Ursae Majoris
• The Kepler view of magnetic chemically peculiar stars
• A search for photometric variability in magnetic chemically peculiar stars using ASAS-3 data
• New Photometrically Variable Magnetic Chemically Peculiar Stars in the ASAS-3 Archive
• Stellar model atmospheres with magnetic line blanketing
• A plethora of new, magnetic chemically peculiar stars from LAMOST DR4
• Are there tangled magnetic fields on HgMn stars?
• TESS Cycle 1 observations of roAp stars with 2-min cadence data
• New and improved rotational periods of magnetic CP stars from ASAS-3, KELT and MASCARA data
• Stellar model atmospheres with magnetic line blanketing. II. Introduction of polarized radiative transfer
• Ultraviolet and visual flux and line variations of one of the least variable Bp stars HD 64740
• Long period Ap stars discovered with TESS data
• Magnetic, chemically peculiar (CP2) stars in the SuperWASP survey
• MOBSTER -- III. HD 62658: a magnetic Bp star in an eclipsing binary with a non-magnetic 'identical twin'
• The variation of the magnetic field of the Ap star HD~50169 over its 29 year rotation period
• Short-term variability and mass loss in Be stars VI. Frequency groups in $\gamma$ Cas detected by TESS
• Long-period Ap stars discovered with TESS data: The northern ecliptic hemisphere
• The 10.5 year rotation period of the strongly magnetic rapidly oscillating Ap star HD 166473
• Detection of weak magnetic fields in two HgMn stars
• New magnetic chemically peculiar stars and candidates in the ATLAS First Catalog of Variable Stars
• New eclipsing binaries with mercury-manganese stars
• Rotational modulation and single g-mode pulsation in the B9pSi star HD174356?

Cited by in corpus (6)

• Photometric White Dwarf Rotation
• A new sample of super-slowly rotating Ap (ssrAp) stars from the Zwicky Transient Facility survey
• Magnetism in LAMOST CP stars observed by TESS
• Discovery of new magnetic δ Scuti stars and impact of magnetism on pulsation excitation
• Horizontal flows in the atmospheres of chemically peculiar stars
• Stellar Magnetism