J/ApJ/955/123 Variability of magnetic hot stars from TESS obs. (Shen+, 2023)
Variability of magnetic hot stars from the TESS observations.
Shen D.-X., Li G., Abdusamatjan I., Fu J.-N., Zhu C.-H., Yu J.-L.,
Zhang Yu, Lu G.-L., Zhai N.-N., Liu J.-Z.
<Astrophys. J., 955, 123 (2023)>
=2023ApJ...955..123S 2023ApJ...955..123S
ADC_Keywords: Spectral types; Stars, early-type; Stars, variable; Optical;
Magnetic fields; Asteroseismology; Effective temperatures
Keywords: Magnetic fields ; Early-type variable stars ; Early-type stars ;
Asteroseismology
Abstract:
Magnetic hot stars refer to stars that have effective temperatures
approximately in the range from 7000-50000K, and with large-scale
globally organized magnetic fields. These magnetic fields exhibit
strengths ranging from tens of Gauss to tens of kilo-Gauss. They are
key in understanding the effects caused by magnetic fields in the
stellar evolution. However, there are only three magnetic hot stars
studied via a combination of spectropolarimetric and asteroseismic
modeling. Combined with Transiting Exoplanet Survey Satellite sectors
1-56 data sets, we provided a photometric variability and stochastic
low-frequency (SLF) variability study of 118 magnetic hot stars. Nine
new rotating variable stars are identified. Using the Bayesian Markov
Chain Monte Carlo framework, we fitted the morphologies of SLF
variability for magnetic hot stars. Our analysis reveals that the
magnetic hot stars in our sample have γ<5.5 with the vast
majority having 1≤γ≤3. The νchar is primarily in the ranges
of 0day-1<νchar<6.3day-1. The amplitude of SLF variability,
log α0, shows a dominant distribution ranging from 0.8-3. No
significant correlations are observed between the luminosity and
fitting parameters, suggesting no clear dependence of SLF variability
on stellar mass for our sample of magnetic hot stars with masses
between approximately 1.5M☉<M<20M☉. We found a significant
negative correlation between the Bp and νchar. This suppression
effect of magnetic fields on νchar may be a result of their
inhibition of macroturbulence.
Description:
In this work, we classified the variability of 118 magnetic hot stars
using short-cadence target pixel files (TPFs) observed by the
Transiting Exoplanet Survey Satellite (TESS) from sectors 1-56
(2018-Jul-25 to 2022-Sep-30).
We use the compilations of the magnetic hot stars including the
results of the Very Large Telescope (VLT) FOcal Reducer and low
dispersion Spectrograph (FORS1; Bagnulo+ 2015, J/A+A/583/A115), the B
fields in OB stars (BOB)/FORS2 (Morel+ 2014Msngr.157...27M 2014Msngr.157...27M &
2015IAUS..307..342M 2015IAUS..307..342M), and the Magnetism in Massive Stars (MiMeS;
Grunhut+ 2017, J/MNRAS/465/2432) surveys.
Other exhaustive studies that identify hot stars with confirmed field
detections are complemented in our catalog. See Section 2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 102 118 Identification numbers, physical parameters and
variability classifications of the 118 magnetic
hot stars
table2.dat 88 189 The Stochastic low-frequency (SLF) fitting parameters
of the magnetic hot stars
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)
IV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021)
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
J/A+AS/123/353 : Mean magnetic field modulus of Ap stars (Mathys, 1997)
J/AJ/117/354 : OB associations from Hipparcos (de Zeeuw+, 1999)
J/A+A/393/965 : Intrinsic freq. of slowly pulsating B stars (de Cat+, 2002)
J/A+A/430/1143 : Stellar magnetic rotational phase curves (Bychkov+, 2005)
J/ApJS/158/193 : Catalog of Galactic β Cephei stars (Stankov+, 2005)
J/A+A/450/763 : Evolutionary state of magnetic CP stars (Kochukhov+, 2006)
J/A+A/492/277 : Analysis of Collinder 69 stars with VOSA (Bayo+, 2008)
J/A+A/506/111 : Freq. analysis of HD 180642 (V1449 Aql) (Degroote+, 2009)
J/A+A/533/A4 : CoRoT photometry of three O-type stars (Blomme+, 2011)
J/A+A/530/A115 : Rotating massive MS stars evolutionary models (Brott+, 2011)
J/A+A/537/A146 : Stellar models with rot. 0.8<M<120, Z=0.014 (Ekstrom+, 2012)
J/MNRAS/426/2208 : Hα variations of O9 subgiant HD57682 (Grunhut+, 2012)
J/A+A/545/A119 : Stromgren v photometry of σ Lup (Henrichs+, 2012)
J/A+A/539/A143 : Nearby B-stars stellar param. and abundances (Nieva+, 2012)
J/other/Sci/337.444 : RV curves of Galactic massive O stars (Sana+, 2012)
J/A+A/537/A120 : Rotational velocities of A-type stars. IV. (Zorec+, 2012)
J/A+A/567/A28 : HARPSpol magnetic massive stars (Alecian, 2014)
J/ApJS/215/15 : SMaSH+: observations and companion detection (Sana+, 2014)
J/A+A/583/A115 : FORS1 catalogue of stellar magnetic fields (Bagnulo+, 2015)
J/A+A/580/A27 : Asteroseismology of KIC 10526294 (Moravveji+, 2015)
J/PAZh/43/521 : 3D map of reddening and extinction (Gontcharov, 2017)
J/MNRAS/465/2432 : MiMeS magnetic analysis of O-type stars (Grunhut+, 2017)
J/A+A/601/A14 : Radial velocities of magnetic Ap stars (Mathys, 2017)
J/MNRAS/468/2745 : Rotational properties of mCP stars (Netopil, 2017)
J/A+A/597/A22 : Massive O- and B-type stars velocities (Simon-Diaz+, 2017)
J/MNRAS/475/5144 : Magnetic early B-type stars. I. (Shultz+, 2018)
J/other/NatAs/3.760 : BSGs low-frequency gravity waves (Bowman+, 2019)
J/A+A/621/A115 : Vela OB2 members (Cantat-Gaudin+, 2019)
J/ApJ/873/L5 : Magnetic fields of Ap/Bp stars (Chojnowski+, 2019)
J/A+A/626/A121 : Buoyancy radius of γ Dor stars (Ouazzani+, 2019)
J/ApJ/872/L9 : TESS obs. of massive O and B stars (Pedersen+, 2019)
J/MNRAS/493/5871 : TESS A and B stars and the Maia variables (Balona+, 2020)
J/A+A/640/A36 : OB stars TESS phot. & high-res. spectroscopy (Bowman+, 2020)
J/A+A/639/A81 : Variability of OB stars (Burssens+, 2020)
J/A+A/640/A40 : 1002 mCP stars from LAMOST DR4 (Hummerich+, 2020)
J/MNRAS/491/3586 : 611 γ Doradus stars Kepler data (Li+, 2020)
J/MNRAS/499/5379 : Longitudinal magnetic field of 6 B stars (Shultz+, 2020)
J/MNRAS/513/1429 : MOBSTER. VI. Magnetospheres of hot stars (Shultz+, 2022)
http://heasarc.gsfc.nasa.gov/docs/tess/ : NASA TESS Science Support Center home
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Name Stellar identifier
13- 22 I10 --- TIC [4289780/2055137574] TESS Input Catalog
identifier
24- 36 A13 --- SpT Spectral type
38- 41 F4.2 [Lsun] logL [0.73/5.7]? Log luminosity
43- 46 F4.2 [Lsun] e_logL [0.01/0.6]? Uncertainty in logL
48- 51 F4.2 K logT [3.83/4.59]? Log effective temperature
53- 56 F4.2 K e_logT [0.0/0.08]? Uncertainty in logT
58- 61 F4.2 [cm/s2] logg [0.0/4.75]? Log surface gravity
63- 66 F4.2 [cm/s2] e_logg [0.0/2.0]? Uncertainty in log (g)
68- 76 A9 --- Ref Reference for spectroscopic analyses (1)
78- 102 A25 --- Var Variability (2)
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Note (1): References as follows:
R1 = Petit et al. 2013MNRAS.429..398P 2013MNRAS.429..398P
R2 = Shultz et al. 2020, J/MNRAS/499/5379
R3 = Gonzalez et al. 2018MNRAS.481L..30G 2018MNRAS.481L..30G
R4 = Shultz et al. 2021MNRAS.504.4850S 2021MNRAS.504.4850S
R5 = Shultz et al. 2019MNRAS.485.1508S 2019MNRAS.485.1508S
R6 = Shultz et al. 2018, J/MNRAS/475/5144
R7 = Kochukhov & Bagnulo 2006, J/A+A/450/763
R8 = Saffe et al. 2005RMxAA..41..415S 2005RMxAA..41..415S
R9 = Netopil et al. 2017, J/MNRAS/468/2745
R10 = Kurtz et al. 2008MNRAS.386.1750K 2008MNRAS.386.1750K
this work = stellar parameters derived from the SED using the VO Sed Analyzer
(VOSA; Bayo & Rodrigo 2008A&A...492..277B 2008A&A...492..277B). See Section 3.4.
Note (2): The variability classification result for each star.
SPB = Slowly Pulsating B star;
β Cep = β Cepheid variable;
rot. = rotating variable;
cont. = constant;
SLF = stochastic low-frequency variable;
δ Sct = δ Scuti;
Multi = binary or multiple star.
Unknown represents we can not identify the classification
using the amplitude spectrum and light curve.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Stellar identifier
13- 19 A7 --- Sector Sector(s)
21- 28 F8.3 umag alpha0 [3.9/3554] Amplitude at zero frequency
30- 35 F6.2 umag e_alpha0 [0.3/384] Lower uncertainty in alpha0
37- 42 F6.2 umag E_alpha0 [0.4/470] Upper uncertainty in alpha0
44- 47 F4.2 --- nuChar [0.05/8.9] Characteristic frequency
49- 52 F4.2 --- e_nuChar [0.01/0.9] Lower uncertainty in nuChar
54- 57 F4.2 --- E_nuChar [0.01/0.8] Upper uncertainty in nuChar
59- 62 F4.2 [-] gamma [0.69/5.7] logarithmic amplitude gradient
64- 67 F4.2 [-] e_gamma [0.01/1.4] Lower uncertainty in gamma
69- 72 F4.2 [-] E_gamma [0.01/2.3] Upper uncertainty in gamma
74- 78 F5.2 umag Cw [0.8/86] White noise term
80- 83 F4.2 umag e_Cw [0/0.3] Lower uncertainty in Cw
85- 88 F4.2 umag E_Cw [0/0.3] Upper uncertainty in Cw
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 02-Dec-2025