J/ApJ/940/27 Pulsator cool supergiants in the MCs (Dorn-Wallenstein+, 2022)
The properties of fast yellow pulsating supergiants: FYPS point the way to
missing red supergiants.
Dorn-Wallenstein T.Z., Levesque E.M., Davenport J.R.A., Neugent K.F.,
Morris B.M., Bostroem K.A.
<Astrophys. J., 940, 27 (2022)>
=2022ApJ...940...27D 2022ApJ...940...27D
ADC_Keywords: Stars, giant; Magellanic Clouds; Effective temperatures;
Infrared sources; Photometry; Optical
Keywords: Massive stars ; Stellar evolution ; Asteroseismology ;
Stellar pulsations ; Stellar mass loss ; Type II supernovae ;
Red supergiant stars ; Late-type supergiant stars ;
Yellow hypergiant stars ; Hertzsprung Russell diagram
Abstract:
Fast yellow pulsating supergiants (FYPS) are a recently discovered
class of evolved massive pulsators. As candidate supergiant objects,
and one of the few classes of pulsating evolved massive stars, these
objects have incredible potential to change our understanding of the
structure and evolution of massive stars. Here we examine the
lightcurves of a sample of 126 cool supergiants in the Magellanic
Clouds observed by the Transiting Exoplanet Survey Satellite in order
to identify pulsating stars. After making quality cuts and filtering
out contaminant objects, we examine the distribution of pulsating
stars in the Hertzprung-Russel (HR) diagram, and find that FYPS occupy
a region above logL/L☉≳5.0. This luminosity boundary
corresponds to stars with initial masses of ∼18-20M☉, consistent
with the most massive red supergiant progenitors of supernovae (SNe)
II-P, as well as the observed properties of SNe IIb progenitors. This
threshold is in agreement with the picture that FYPS are post-RSG
stars. Finally, we characterize the behavior of FYPS pulsations as a
function of their location in the HR diagram. We find low-frequency
pulsations at higher effective temperatures, and higher-frequency
pulsations at lower temperatures, with a transition between the two
behaviors at intermediate temperatures. The observed properties of
FYPS make them fascinating objects for future theoretical study.
Description:
As in Dorn-Wallenstein+ (2020, J/ApJ/902/24), we use the sample of
yellow supergiants (YSGs) from Neugent+ (2010, J/ApJ/889/44 and
2012, J/ApJ/749/177), who used spectra obtained with the Hydra
multiobject spectrograph on the Cerro Tololo 4m telescope to confirm
the membership of a large sample of YSGs and RSGs in the Large
Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC), along with
updated formulae derived from Kurucz (Kurucz 1992IAUS..149..225K 1992IAUS..149..225K) and
MARCS (Gustafsson+ 2008A&A...486..951G 2008A&A...486..951G) to obtain effective
temperatures (logTeff) and luminosities (logL/L☉) from
near-infrared photometry.
We crossmatched this sample to the latest version of the TESS Input
Catalog (TIC, see Stassun+ 2018, J/AJ/156/102) available on the
Mikulski Archive for Space Telescopes (MAST). We selected all stars
that had been observed by TESS at a 2 minute cadence in the southern
hemisphere using target lists for TESS Sectors 1-13 (Year 1) and 27-39
(Year 3).
We also crossmatched our sample with the catalog of Magellanic Cloud
stars from Gaia Collaboration+ (2018, J/A+A/616/A12), which uses data
from Gaia DR2 (Gaia Coll.+ 2018, see I/345). This allows us to discard
a further 18 stars in our sample as being likely foreground objects.
After discarding these objects, the sample contains a total of
201 stars. However, upon inspection of the spectral types available in
the literature for these stars, we found that 75 of them are actually
B-type stars.
This leaves us with a sample of 126 stars --101 in the LMC, and 25 in
the SMC --which nearly doubles the size of the sample in
Dorn-Wallenstein+ (2020), and extends our work to the SMC for the
first time.
See Section 2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 147 14 Fast yellow pulsating supergiants (FYPS) identified
in the LMC
tableb2.dat 147 3 Fast yellow pulsating supergiants (FYPS) identified
in the SMC
tableb3.dat 147 27 Pulsating stars below logL/L☉=5.0 identified
in the LMC
tableb4.dat 147 9 Pulsating stars below logL/L☉=5.0 identified
in the SMC
tableb5.dat 147 55 Nonpulsating stars identified in the LMC
tableb6.dat 147 13 Nonpulsating stars identified in the SMC
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See also:
B/gcvs : General Catalogue of Variable Stars (Samus+, 2007-2017)
III/147 : Studies of LMC stellar content (Rousseau+ 1978)
III/150 : Perkins Revised MK Types for the Cooler Stars (Keenan+ 1989)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)
IV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021)
II/195 : Namelists of variable stars Nos.67-73 (Khopolov+, 1985-97)
J/A+AS/24/35 : LMC A-F supergiants (Stock+, 1976)
J/A+AS/30/261 : UBV and RVs of SMC Supergiants (Ardeberg+, 1977)
J/A+A/363/L1 : The distance modulus of the LMC (Kovacs, 2000)
J/AJ/119/2214 : Photometry of Magellanic OB associations (Massey+, 2000)
J/A+A/456/623 : VLT-FLAMES survey of massive stars (Evans+, 2006)
J/AJ/132/2268 : SAGE calibration stars (Meixner+, 2006)
J/MNRAS/395/1409 : Type II-P SN progenitor constraints (Smartt+, 2009)
J/ApJ/719/1784 : Yellow supergiants in the SMC (Neugent+, 2010)
J/A+A/533/A4 : CoRoT photometry of three O-type stars (Blomme+, 2011)
J/A+A/537/A146 : Stellar models with rot., Z=0.014 (Ekstrom+, 2012)
J/ApJ/749/177 : Yellow and red supergiants in the LMC (Neugent+, 2012)
J/other/Sci/337.444 : RV curves of Galactic massive O stars (Sana+, 2012)
J/ApJ/746/16 : Modelling the convection zone (van Saders+, 2012)
J/A+A/558/A103 : Stellar models with rot., Z=0.002 (Georgy+, 2013)
J/A+A/558/A131 : Model sp. of hot stars at the pre-SN stage (Groh+, 2013)
J/A+A/560/A16 : Comparison of evolutionary tracks (Martins+, 2013)
J/A+A/550/A107 : RV catalogue of O stars in 30 Doradus (Sana+, 2013)
J/ApJS/215/15 : SMaSH+: obs. and companion detection (Sana+, 2014)
J/A+A/578/A3 : Supergiants in the MCs (Gonzalez-Fernandez+, 2015)
J/ApJ/825/50 : Var. stars in M31 & M33. III. YSGs & RSGs (Gordon+, 2016)
J/A+A/618/A137 : MC cool supergiants spectra (Dorda+, 2018)
J/A+A/616/A12 : GaiaDR2 sources in GC & dSph (Gaia Collaboration+, 2018)
J/AcA/68/89 : VI LCs of SMC type II Cepheids (Soszynski+, 2018)
J/AJ/156/102 : TESS Input Cat. & Candidate Target List (Stassun+, 2018)
J/other/NatAs/3.760 : Blue supergiants low-freq. gravity waves (Bowman+, 2019)
J/ApJ/875/124 : Bin. red supergiants. II. B-type comp. (Neugent+, 2019)
J/A+A/629/A91 : A source catalog for the SMC (Yang+, 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. sp. (Bowman+, 2020)
J/ApJ/902/24 : Evolved stars with TESS. II. (Dorn-Wallenstein+, 2020)
J/ApJ/889/44 : UKIRT obs. of red supergiants in M31 (Neugent+, 2020)
J/A+A/646/A141 : A source catalog for the LMC (Yang+, 2021)
http://tess.mit.edu/observations/ : TESS observations webpage
Byte-by-byte Description of file: tableb*.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 25 A25 --- Name Common name of the star
27- 35 I9 --- TIC [29984014/425084797] TIC number
37- 47 F11.8 deg RAdeg Right ascension (J2000)
49- 60 F12.8 deg DEdeg [-73.8/-66.2] Declination (J2000)
62- 67 F6.3 mag Tmag [7.7/12] TESS magnitude
69- 73 F5.3 [K] logTeff [3.6/4.04] Log of effective temperature (1)
75- 79 F5.3 [Lsun] logL [4.3/5.72] Log of the luminosity,
logL/L☉ (1)
81- 82 I2 --- Nf [1/30]? Number of frequencies recovered via
iterative prewhitening (empty for nonpulsating
stars)
84- 89 F6.3 d-1 f0 [0.038/29.9]? Highest amplitude recovered
frequency (empty for nonpulsating stars)
91-101 A11 --- SpT Spectral type
103-147 A45 --- r_SpT Reference for SpT
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Note (1): Typical uncertainties in logTeff and logL are 0.015 dex and 0.10 dex,
respectively.
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 01-Oct-2024