J/A+A/611/A69 B, V and R band polarimetry of lambda Tau (Berdyugin+, 2018)
High-precision broad-band polarimetry of early-type binaries.
II. Variable, phase-locked polarization in triple Algol-type system
lambda Tauri.
Berdyugin A., Piirola V., Sakanoi T., Kagitani M., Yoneda M.
<Astron. Astrophys. 611, A69 (2018)>
=2018A&A...611A..69B 2018A&A...611A..69B (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Polarization
Keywords: polarization - scattering - binaries: eclipsing -
techniques: polarimetric - circumstellar matter
Abstract:
Linear polarization measurements of lambda Tau in the B, V and R
passbands with the high-precision Dipol-2 polarimeter have been
carried out. The data have been obtained on the 60cm KVA (Observatory
Roque de los Muchachos, La Palma, Spain) and Tohoku 60cm (Haleakala,
Hawaii, USA) remotely controlled telescopes during 69 observing
nights. Optical polarimetry revealed small intrinsic polarization with
∼0.05% peak to peak variation over the orbital period of ∼3.95d.
Variability pattern is typical for binary systems showing strong
second harmonic of the orbital period. We apply a standard analytical
method and our own light scattering models to derive parameters of the
inner binary orbit from the fit to the observed variability of the
normalized Stokes parameters. Analytic and numerical modelling codes
are used to interpret the data.
Description:
Obtained polarization data of lambda Tau in the form of the normalized
Stokes parameters q and u are presented for the B, V and R passbands.
Objects:
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RA (2000) DE Designation(s)
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04 00 40.82 +12 29 25.2 lambda Tau = HR 1239
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
poldata.dat 97 69 Polarization data for the B, V and R passbands
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Byte-by-byte Description of file: poldata.dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d JD Heliocentrical Julian Date
15- 20 F6.4 --- Phase Orbital phase (1)
23- 28 F6.4 --- q(B) Stokes q for B band
31- 37 F7.4 --- u(B) Stokes u for B band
40- 45 F6.4 --- e_q(B) Error of q(B) and u(B)
49- 54 F6.4 --- q(V) Stokes q for V band
57- 63 F7.4 --- u(V) Stokes u for V band
66- 71 F6.4 --- e_q(V) Error of q(V) and u(V)
75- 80 F6.4 --- q(R) Stokes q for R band
83- 89 F7.4 --- u(R) Stokes u for R band
92- 97 F6.4 --- e_q(R) Error of q(R) and u(R)
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Note (1): The phase of the orbital period was computed with the ephemeris
JD(pr.min)=2455577.3203+3.952948d.
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Acknowledgements:
Andrei Berdyugin, andber(at)utu.fi
(End) Andrei Berdyugin [Turku Univ., Finland] Patricia Vannier [CDS] 08-Jan-2018