J/A+A/669/A48 Southern short-period pulsating hot-subdwarf stars (Baran+, 2023)
Short-period pulsating hot-subdwarf stars observed by TESS.
I. Southern ecliptic hemisphere.
Baran A.S., Van Grootel V., Ostensen R.H., Worters H.L., Sahoo S.K.,
Sanjayan S., Charpinet S., Nemeth P., Telting J.H., Kilkenny D.
<Astron. Astrophys. 669, A48 (2023)>
=2023A&A...669A..48B 2023A&A...669A..48B (SIMBAD/NED BibCode)
ADC_Keywords: Asteroseismology ; Stars, variable ; Optical
Keywords: stars: oscillations - stars: variables: general -
stars: horizontal-branch - subdwarfs
Abstract:
We present results of a Transiting Exoplanet Survey Satellite (TESS)
search for short-period pulsations in compact stellar objects observed
in years 1 and 3 of the TESS mission, during which the southern
ecliptic hemisphere was targeted. We describe the TESS data used and
the details of the search method. For many of the targets, we use
unpublished spectroscopic observations to classify the objects. From
the TESS photometry, we clearly identify 43 short-period hot-subdwarf
pulsators, including 32 sdB stars, eight sdOB stars, two sdO stars,
and, significantly, one He-sdOB star, which is the first of this kind
to show short-period pulsations. Eight stars show signals at both low
and high frequencies, and are therefore "hybrid" pulsators.We
report the list of prewhitened frequencies and we show the amplitude
spectra calculated from the TESS data. We make an attempt to identify
possible multiplets caused by stellar rotation, and we select four
candidates with rotation periods between 1 and 12.9d. The most
interesting targets discovered in this survey should be observed
throughout the remainder of the TESS mission and from the ground.
Asteroseismic investigations of these data sets will be invaluable in
revealing the interior structure of these stars and will boost our
understanding of their evolutionary history. We find three additional
new variable stars but their spectral and variability types remain to
be constrained.
Description:
We present the results of our search for short-period pulsating hot
subdwarfs.We used TESS space data collected mostly during years 1 and
3, covering the southern ecliptic hemisphere. We report the stars that
show signals at high frequencies, which we associate with p-mode
pulsations. In most cases the amplitudes of p modes dominate amplitude
spectra.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
sources.dat 12 31 List of sources with frequencies in table 4
table4.dat 111 292 List of frequencies we detected in the targets
observed in the ultra-short cadence (USC)
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See also:
IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)
Byte-by-byte Description of file: sources.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Source Source name (TIC NNNNNNNN)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Source Source name (TIC NNNNNNNN)
13- 27 A15 --- n_Source Note
30- 36 A7 --- ID Frequency ID
39- 50 F12.6 uHz Freq Frequency
53- 59 F7.5 uHz e_Freq ? Frequency error
61- 73 F13.6 s Per Period
78- 87 F10.6 s e_Per ? Period error
93- 99 F7.3 10-3 Amp Amplitude (in ppt)
101-105 F5.3 10-3 e_Amp ? Amplitude error (in ppt)
107-111 F5.1 --- S/N Signal-to-noise ratio
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Acknowledgements:
Andy Baran, andysbaran(at)gmail.com
(End) Patricia Vannier [CDS] 28-Nov-2022