J/MNRAS/415/1577 CoRoT 105288363 Blazhko modulation (Guggenberger+, 2011)
The CoRoT star 105288363: strong cycle-to-cycle changes of the Blazhko
modulation.
Guggenberger E., Kolenberg K., Chapellier E., Poretti E., Szabo R.,
Benko J.M., Paparo M.
<Mon. Not. R. Astron. Soc., 415, 1577-1589 (2011)>
=2011MNRAS.415.1577G 2011MNRAS.415.1577G
ADC_Keywords: Stars, variable ; Spectroscopy
Keywords: techniques: photometric - stars: individual: CoRoT ID 105288363 -
stars: variables: RR Lyrae
Abstract:
We present an analysis of the COnvection, ROtation and planetary
Transits (CoRoT) star 105288363, a new Blazhko RR Lyrae star of type
RRab (f0=1.7623d-1), observed with the CoRoT spacecraft during the
second long run in the direction of the Galactic Centre (LRc02,
time-base 145d). The CoRoT data are characterized by an excellent
time-sampling and a low noise amplitude of 0.07mmag in the 2-12d-1
range and allow us to study not only the fine details of the
variability of the star, but also long-term changes in the pulsation
behaviour and the stability of the Blazhko cycle. We use, among other
methods, standard Fourier analysis techniques and O-C diagrams to
investigate the pulsational behaviour of the Blazhko star 105288363.
In addition to the frequency pattern expected for a Blazhko RR Lyrae
star, we find an independent mode (f1=2.984d-1) showing a f0/f1
ratio of 0.59 which is similar to that observed in other Blazhko RR
Lyrae stars. The bump and hump phenomena are also analysed, with their
variations over the Blazhko cycle. We carefully investigated the
strong cycle-to-cycle changes in the Blazhko modulation (PB=35.6d),
which seem to happen independently and partly diametrically in the
amplitude and phase modulations. Furthermore, the phasing between the
two types of modulations is found to change during the course of the
observations.
Description:
The data used in this study were obtained in the framework of the
Additional Programmes of the exoplanetary field during the second long
run in the direction of the Galactic Centre (LRc02). Observations were
carried out during a time-span of 145 d from 2008 April 15 to 2008
September 7, or CoRoT JD 3027.47 to 3172.46.
Objects:
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RA (2000) DE Designation(s)
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18 39 30.87 +07 26 55.3 CoRoT 105288363 = CoRoT 105288363
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 43 79 *List of frequencies, amplitudes and phases
obtained from the analysis of the full data set
(all cycles combined), assuming equidistant
multiplets
table3.dat 54 256 Observed maxima and minima of the pulsation of
CoRoT ID 105288363
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Note on table1.dat: The values should be understood as mean values, as the
properties of the pulsation change from cycle to cycle.
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See also:
B/corot : CoRoT observation log Release 7 (CoRoT, 2011)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- Type [FBTQI] Type of frequency (1)
3- 10 A8 --- Name Name of the frequency
12- 19 F8.5 d-1 Freq Frequency (2)
22- 28 F7.5 mag Amp Amplitude (Errors are 0.00028mag)
30- 35 F6.4 --- phi [0/1] Phase
38- 43 F6.4 --- e_phi [0/1] rms uncertainty on phi obtained from a
Monte Carlo (MC) simulation with Period04
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Note (1): Type of frequency as follows:
F = main frequency
B = Blazhko frequency
T = Significant triplet components
Q = Significant quintuplet components
I = Independent mode
Note (2): Errors are 0.00004, 0.0002 and 0.0014d-1 for the three independent
frequencies, that is, for the main frequency f0, for its highest side peak
(f0-fB), which was used for fixing the spacings, and for f1, respectively.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- E Epoch (cycle)
5- 13 F9.4 d Tmax ?=- Times of maximum (HJD-2450000)
15- 21 F7.4 mag magM ?=- Relative magnitude at Tmax
23- 29 F7.4 d O-CM ?=- O-C at Tmax
31- 39 F9.4 d Tmin ?=- Times of minimum (HJD-2450000)
41- 46 F6.4 mag magm ?=- Relative magnitude at Tmin
48- 54 F7.4 d O-Cm ?=- O-C at Tmin
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 01-Mar-2012