J/MNRAS/461/4059 The pulsations of G 207-9 and LP 133-144 (Bognar+, 2016)
G 207-9 and LP 133-144: light curve analysis and asteroseismology of two
ZZ Ceti stars.
Bognar Zs., Paparo M., Molnar L., P. I. Papics, Plachy E., Verebelyi E.,
Sodor A.
<Mon. Not. R. Astron. Soc. 461, 4059 (2016)>
=2016MNRAS.461.4059B 2016MNRAS.461.4059B
ADC_Keywords: Stars, variable ; Stars, white dwarf ; Photometry, CCD
Keywords: techniques: photometric - stars: individual: G 207-9 -
stars: individual: LP 133-144 - stars: interiors -
stars: oscillations - white dwarfs
Abstract:
G 207-9 and LP 133-144 are two rarely observed ZZ Ceti stars located
in the middle and close to the blue edge of the ZZ Ceti instability
domain, respectively. We aimed to observe them at least during one
observing season at Konkoly Observatory with the purpose of extending
the list of known pulsation modes for asteroseismic investigations and
detect any significant changes in their pulsational behaviour. We
determined five and three new normal modes of G 207-9 and LP 133-144,
respectively. In LP 133-144, our frequency analysis also revealed that
at least at three modes there are actually triplets with frequency
separations of ∼4Hz. The rotational period of LP 133-144 based on the
triplets is ~=42h. The preliminary asteroseismic fits of G 207-9
predict Teff=12000 or 12400K and M=0.855--0.870M☉ values for the
effective temperature and mass of the star, depending on the
assumptions on the spherical degree (l) values of the modes. These
results are in agreement with the spectroscopic determinations. In the
case of LP 133-144, the best-fitting models prefer Teff=11800K in
effective temperature and M*≥0.71M☉ stellar masses, which are
more than 0.1M☉ larger than the spectroscopic value.
Description:
We observed G 207-9 and LP 133-144 on 24 and 28 nights in the 2007
observing season, respectively. We used the 1m Ritchey-Chretien-Coude
telescope at Piszkesteto mountain station of Konkoly Observatory. The
measurements were made with a Princeton Instruments VersArray:1300B
back-illuminated CCD camera in white light and with 10 or 30s
integration times.
Objects:
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RA (2000) DE Designation(s)
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18 57 30.17 +33 57 25.2 G 207-9 = V* V470 Lyr
13 51 20.24 +54 57 42.6 LP 133-144 = V* V359 UMa
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
g207.dat 25 16388 CCD observations of G 207-9 at Konkoly observatory
lp133.dat 29 21617 CCD observations of LP 133-144 at Konkoly observatory
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See also:
J/ApJ/631/1100 : Atmospheric parameters of DA white dwarfs (Gianninas+, 2005)
J/A+A/528/A147 : CoRoT 101155310 light curve (Poretti+, 2011)
J/A+A/570/A116 : Monitoring of the V777 Her star KUV 05134+2605 (Bognar+, 2014)
Byte-by-byte Description of file: g207.dat lp133.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] 23-Jun-2016