J/A+A/676/A28 Six ULA Cepheids light curves (Tarczay-Nehez+, 2023)
Testing ultralow amplitude Cepheid candidates in the Galactic disk
by TESS and Gaia.
Tarczay-Nehez D., Molnar L., Bodi A., Szabo R.
<Astron. Astrophys. 676, A28 (2023)>
=2023A&A...676A..28T 2023A&A...676A..28T (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Photometry ; Optical
Keywords: stars: variables: Cepheids - stars: variables: general -
Hertzsprung-Russell and C-M diagrams - techniques: photometric
Abstract:
Ultra-low amplitude (ULA) and strange mode Cepheids are thought to be
pulsating variable stars that are near to or are at the edges of the
classical instability strip. Until now, a few dozen such variable star
candidates have been found both in the Large Magellanic Cloud and the
Milky Way. In this present work, we studied six ULA Cepheid candidates
in the Milky Way, identified by Szabo et al. (2009, in American
Institute of Physics Conference Series, Vol. 1170, Stellar Pulsation:
Challenges for Theory and Observation, ed. J.A. Guzik & P.A. Bradley,
102-104) using CoRoT and 2MASS data. In order to identify their
positions in the period--luminosity and color-magnitude diagrams, we
used the Gaia DR3 parallax and brightness data of each star to
calculate their reddening-free absolute magnitudes and distances.
Furthermore, we calculated the Fourier parameters (e.g., period and
amplitude) of the light variations based on CoRoT and TESS
measurements, and established the long-term phase shifts for four out
of six stars. Based on the results, we conclude that none of the six
ULA Cepheid candidates are pulsating variable stars, but rather
rotation-induced variable stars (rotational spotted and alpha2 Canum
Venaticorum variables) that are either bluer or fainter than Cepheids
would be.
Description:
CoRoT and TESS (sector 06 and 33) photometric data of the 6 ULA
Cepheid candidates.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 83 6 List of studied stars
tablea1.dat 44 96833 CoRoT light curves
tablea2.dat 45 26354 TESS light curves
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See also:
B/corot : CoRoT observation log (N2-4.4) (CoRoT, 2016)
IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- CoRoT CoRoT identifier
11- 19 F9.5 deg RAdeg Right ascension (J2000) (from table 1)
21- 28 F8.5 deg DEdeg Declination (J2000) (from table 1)
30- 36 F7.4 d Per Period (from table 1)
38- 46 I9 --- TIC TESS identifier (from table 3)
48- 66 I19 --- GaiaDR3 Gaia DR3 identifier (from table 3)
68- 83 A16 --- 2MASS 2MASS identifier (HHMMSSss+DDMMSSs)
(from table 2)
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- CoRoT CoRoT ID
11- 23 F13.5 d BJD Barycentic Julian date of the measurement
25- 31 F7.4 mag Wmag CoRoT white magnitude
33- 38 F6.4 mag e_Wmag Error of CoRoT white magnitude
40- 44 A5 --- Run Run
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 I9 --- CoRoT CoRoT ID
11- 23 F13.5 d BJD Barycentic Julian date of the measurement
25- 31 F7.4 mag Tmag TESS magnitude
33- 38 F6.4 mag e_Tmag Error of CoRoT white magnitude
40- 45 A6 --- Sector Sector ID
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Acknowledgements:
Dora Tarczay-Nehez, tarczaynehez.dora(at)csfk.org
(End) Patricia Vannier [CDS] 16-Jun-2023