J/A+A/506/143 Pulsations of HD 181231 (Neiner+, 2009)
The pulsations of the B5IVe star HD181231 observed with CoRoT and ground-based
spectroscopy.
Neiner C., Gutierrez-Soto J., Baudin F., de Batz B., Fremat Y., Huat A.-L.,
Floquet M., Hubert A.-M., Leroy B., Diago P.D., Poretti E., Carrier F.,
Rainer M., Catala C., Thizy O., Buil C., Ribeiro J., Andrade L., Emilio M.,
Espinosa Lara F., Fabregat J., Janot-Pacheco E., Martayan C., Semaan T.,
Suso J., Baglin A., Michel E., Samadi R.
<Astron. Astrophys. 506, 143 (2009)>
=2009A&A...506..143N 2009A&A...506..143N
ADC_Keywords: Stars, early-type ; Stars, Be ; Spectroscopy ; Polarization
Keywords: stars: early-type - stars: emission-line, Be -
stars: individual: HD181231 - stars: rotation - stars: oscillations
Abstract:
HD181231 is a B5IVe star, which has been observed with the CoRoT
satellite during ∼5 consecutive months and simultaneously from the
ground in spectroscopy and spectropolarimetry.
By analysing these data, we aim to detect and characterize as many
pulsation frequencies as possible, to search for the presence of
beating effects possibly at the origin of the Be phenomenon. Our
results will also provide a basis for seismic modelling.
The fundamental parameters of the star are determined from spectral
fitting and from the study of the circumstellar emission. The CoRoT
photometric data and ground-based spectroscopy are analysed using
several Fourier techniques: Clean-ng, Pasper, and Tisaft, as well as a
time-frequency technique. A search for a magnetic field is performed
by applying the LSD technique to the spectropolarimetric data.
Description:
Frequencies (in c/d and microHz) detected in the CoRoT data of
HD181231 with the TiSAFT, Clean-NG, and Pasper methods. The minimum
detectable frequency is 1/T=0.0064 c/d, i.e., 0.075microHz, where T
is the length of the run. The error bar of the frequencies is
Delta_f=1/(4T)=0.0016 c/d, i.e., 0.019 microHz. The amplitudes and
phases calculated with Amphi for each of the three sets of frequencies
are reported in Cols. 5 and 6 together with their error bars. The last
column gives our interpretation of each frequency.
Objects:
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RA (2000) DE Designation(s)
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19 19 42.4 -00 02 59 HD 181231 = HIP 94988
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 90 84 *Frequencies detected in the CoRoT data of
HD 181231 with the TiSAFT, Clean-NG, and
Pasper methods.
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Note on table5.dat: The minimum detectable frequency is 1/T=0.0064c/d,
i.e., 0.075uHz, where T is the length of the run. The error bar of
the frequencies is Δf=1/(4T)=0.0016c/d, i.e., 0.019uHz.
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See also:
B/corot : CoRoT observation log (CoRoT, 2009)
Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 6 F6.4 d-1 FreqT ? TISAFT frequency
9- 14 F6.4 d-1 FreqC ? CLEAN-NG frequency
17- 22 F6.4 d-1 FreqP ? PASPER frequency
24- 29 F6.3 uHz Freq Frequency
31- 40 F10.4 umag Amp Amplitude calculated with Amphi
42- 48 F7.2 umag e_Amp rms uncertainty on Amp
50- 53 F4.2 rad Phase Phase (0/2pi) calculated with Amphi
56- 59 F4.2 rad e_Phase rms uncertainty on Phase
61 A1 --- Flag [a-t] Association flag (1)
62 A1 --- --- []
64- 90 A27 --- Int Interpretation of frequency
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Note (1): Association flag:
For interpretation with associated frequencies, a letter following
indicates the association.
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Acknowledgements:
Coralie Neiner, Coralie.Neiner(at)obspm.fr
(End) Patricia Vannier [CDS] 30-Oct-2009