J/A+A/651/A14 PM J22299+3024 and LP 119-10 light curves (Bognar+, 2021)
Exploring the pulsational properties of two ZZ Ceti stars.
Bognar Zs., Kalup Cs., Sodor A.
<Astron. Astrophys. 651, A14 (2021)>
=2021A&A...651A..14B 2021A&A...651A..14B (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Stars, white dwarf ; Photometry, CCD
Keywords: techniques: photometric - stars: individual: PM J22299+3024 -
stars: individual: LP 119-10 - stars: interiors -
stars: oscillations - white dwarfs
Abstract:
We continued our ground-based observing project with the season-long
observations of ZZ Ceti stars at the Konkoly Observatory. Our present
targets are the newly discovered PM J22299+3024 and the already known
LP 119-10 variables. LP 119-10 was also observed by the TESS space
telescope in 120-second cadence mode.
Our main aims are to characterise the pulsation properties of the
targets and extract pulsation modes from the data for asteroseismic
investigations.
We performed a standard Fourier analysis of the daily, weekly, and
entire data sets, together with test data of different combinations of
weekly observations. We then performed asteroseismic fits utilising
the observed and the calculated pulsation periods. For the
calculations of model grids necessary for the fits, we applied the
2018 version of the White Dwarf Evolution Code.
We derived six possible pulsation modes for PM J22299+3024 and five
plus two TESS pulsation frequencies for LP 119-10. We note that
further pulsation frequencies may be present in the data sets, but we
found their detection ambiguous, so we omitted them from the final
frequency list. Our asteroseismic fits of PM J22299+3024 give 11400K
and 0.46M☉ for the effective temperature and the stellar mass,
respectively. The temperature is ∼800K higher, while the mass of
the model star is exactly the same as was earlier derived by
spectroscopy. Our model fits of LP 119-10 put the effective
temperature in the range of 11800-11900K, which is again higher than
the spectroscopic 11290K value. Moreover, our best model solutions
give M*=0.70M☉ mass for this target, which is near to the
spectroscopic value of 0.65M☉ and likewise in the case of PM
J22299+3024. The seismic distances of our best-fit model stars agree
with the Gaia astrometric distances of PM J22299+3024 and LP 119-10
within the errors, validating our model results.
Description:
We collected data on 14 and 6 nights in the 2018 and 2019 observing
seasons on PM J22299+3024, respectively, while we observed LP 119-10
on 15 nights in the 2018/2019 observing season. We performed the
observations with the 1-m Ritchey-Chretien-Coude telescope located
at the Piszkesteto mountain station of Konkoly Observatory, Hungary.
We obtained data with an FLI Proline 16803 CCD camera in white light.
The exposure times were selected to be 45s and 30s in most cases
for PM J22299+3024 (fainter target) and LP 119-10, respectively.
We applied longer exposures, up to 60s, in the case of unfavourable
weather conditions. The read-out time was ∼3s.
Objects:
------------------------------------------------------------
RA (2000) DE Designation(s)
------------------------------------------------------------
22 29 58.08 +30 24 10.0 PM J22299+3024 = PM J22299+3024
05 02 34.19 +54 01 08.5 LP 119-10 = PM J05025+5401
------------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
lp119.dat 29 9016 CCD observations of LP 119-10 at Konkoly
Observatory
pmj22299.dat 29 11419 CCD observations of PM J22299+3024 at Konkoly
Observatory
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Byte-by-byte Description of file: lp119.dat pmj22299.dat
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Bytes Format Units Label Explanations
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1- 17 F17.9 d BJD Barycentric Julian dates in Barycentric
Dynamical Time (BJD_TDB)
19- 29 F11.8 mag Dmag Differential magnitude
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Acknowledgements:
Zsofia Bognar, bognar(at)konkoly.hu
(End) Zsofia Bognar [Konkoly Obs.], Patricia Vannier [CDS] 07-Apr-2021