J/MNRAS/516/2080 Variability of δ Scuti stars with TESS LC (Barac+, 2022)
Revisiting bright δ Scuti stars and their period-luminosity relation
with TESS and Gaia DR3.
Barac N., Bedding T.R., Murphy S.J., Hey D.R.
<Mon. Not. R. Astron. Soc. 516, 2080-2094 (2022)>
=2022MNRAS.516.2080B 2022MNRAS.516.2080B (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Photometry ; Optical ; Stars, distances ;
Extinction
Keywords: parallaxes - stars: oscillations - stars: variables: δ Scuti
Abstract:
We have used NASA's TESS mission to study catalogued δ Scuti
stars. We examined TESS light curves for 434 stars, including many for
which few previous observations exist. We found that 62 are not
δ Scuti pulsators, with most instead showing variability from
binarity. For the 372 δ Scuti stars, we provide a catalogue of
the period and amplitude of the dominant pulsation mode. Using Gaia
DR3 parallaxes, we place the stars in the period-luminosity (P-L)
diagram and confirm previous findings that most stars lie on a ridge
that corresponds to pulsation in the fundamental radial mode, and that
many others fall on a second ridge that is a factor two shorter in
period. This second ridge is seen more clearly than before, thanks to
the revised periods and distances. We demonstrate the value of the P-L
diagram in distinguishing δ Scuti stars from short-period RR
Lyrae stars, and we find several new examples of high-frequency
δ Scuti stars with regular sequences of overtone modes,
including XX Pyx and 29 Cyg. Finally, we revisit the sample of δ
Scuti stars observed by Kepler and show that they follow a tight
period-density relation, with a pulsation constant for the fundamental
mode of Q = 0.0315 d.
Description:
We have used TESS light curves (i.e available on
https://archive.stsci.edu/) from the first 3 yr of the mission to
study catalogued δ Sct stars, including many for which few
ground-based observations exist, in order to confirm their status and
measure their dominant pulsation modes. We use our revised data,
together with Gaia DR3 parallaxes, to place these targets more
accurately in the P-L diagram (i.e see section Introduction).
Our sample is based on 301 δ Sct Stars from Rodriguez et al.
(2000A&AS..144..469R 2000A&AS..144..469R, Cat. J/A+AS/144/469) which have Vmag < 12 and
2-min TESS light curves. We added 133 δ Sct Stars from Chang et
al. (2013AJ....145..132C 2013AJ....145..132C, Cat. J/AJ/145/132) having also Vmag < 12 and
2-min TESS light curves. Then as explained in section 3, we extract
pulsation modes from TESS light curves giving us two sorted stars
groups, 62 non δ Sct Stars (i.e section 3.2) with binaries
pulsations and 372 confirmed δ Sct Stars. In that way, we give
the names of non δ Sct Stars in table1.dat while for confirmed
δ Sct Stars sample in table2.dat, we computed their distances,
dust extinctions and absolute VMag magnitudes related to P-L relation
as detailed in section 4.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 28 62 Compilation of 62 stars identified as
non-δ Sct stars
table2.dat 83 372 Properties of δ Sct stars in our sample
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See also:
J/MNRAS/491/3586 : 611 γ Doradus stars Kepler data (Li+, 2020)
J/A+A/477/907 : Beta Cephei stars in the ASAS-3 data. I. (Pigulski+, 2008)
J/A+AS/144/469 : Delta Scuti stars (Rodriguez+, 2000)
J/AJ/145/132 : New catalog of 1578 δ Scuti stars (Chang+, 2013)
J/AJ/155/45 : Metal-rich RRc stars in the Carnegie RR Lyrae Survey
(Sneden+, 2018)
J/ApJS/258/8 : LCs of RR Lyrae stars from TESS (Molnar+, 2022)
J/PASP/133/H4201 : Times of maxima for 23 delta Scuti stars (Poro+, 2021)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
II/366 : ASAS-SN catalog of variable stars (Jayasinghe+, 2018-2020)
IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- HD ? HD designation number as HD NNNNNN (HD)
8- 16 A9 --- Name Star name (Name)
18- 26 I9 --- TIC TIC number identifier (TIC)
28 I1 --- r_Name [0/1]? Flag indicates reference (R2000) (1)
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Note (1): Star references are as follows:
0 = Stars originally from Chang et al. 2013AJ....145..132C 2013AJ....145..132C,
Cat. J/AJ/145/132, 41 stars in our sample
1 = Stars originally from Rodriguez et al. 2000A&AS..144..469R 2000A&AS..144..469R,
Cat. J/A+AS/144/469, 21 stars in our sample
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- HD ? HD designation number as HD NNNNNN (HD)
8- 18 A11 --- Name Star name (Name)
20- 28 I9 --- TIC TIC number identifier (TIC)
30 I1 --- r_Name [0/1]? Flag indicates reference (R2000) (1)
32- 36 F5.2 1/d fcat ? Published dominant frequency from previous
references (fcat)
38- 42 F5.2 1/d f1 Frequency of the dominant frequency measured with
our TESS light curves (f1)
44- 47 F4.2 10-12 a1 Amplitude of the dominant frequency measured with
our TESS light curves (a1)
49- 55 F7.2 pc Dist ? Star distance based on values from GaiaDR3
(Gaia Collaboration Cat. I/355) and computed as
explianed in section 4 P-L relation (dist)
57- 62 F6.2 pc e_Dist ? Mean uncertainty of Dist (e_dist)
64- 67 F4.2 mag AV Interstellar dust extinction calculated by
fitting the star SED (AV) (2)
69- 72 F4.2 mag e_AV Mean uncertainty of AV (e_AV)
74- 78 F5.2 --- VMag Absolute V-band magnitude related to period,
distance, parallax and AV values as equations 1,
3 and 4 of the section 4 P-L relation show (MV)
80- 83 F4.2 --- e_VMag Mean uncertainty of VMag (e_MV)
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Note (1): Star references are as follows:
0 = Stars originally from Chang et al. 2013AJ....145..132C 2013AJ....145..132C,
Cat. J/AJ/145/132, 92 stars in our sample
1 = Stars originally from Rodriguez et al. 2000A&AS..144..469R 2000A&AS..144..469R,
Cat. J/A+AS/144/469, 280 stars in our sample
Note (2): As resumed in section 4, the extinction due to interstellar dust
was calculated by fitting the spectral energy distribution of each
star using the astroariadne. For each star, we queried photometric
data from VizieR. The stars were then fitted to the Castelli & Kurucz
(2003IAUS..210P.A20C) model using a nested sampling algorithm called
dynesty in order to obtain AV values.
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History:
From electronic version of the journal
(End) Luc Trabelsi [CDS] 16-Jul-2025