J/A+A/383/580 BV polarimetric variability of 3 O-type stars (Clarke+, 2002)
On the polarimetric variability of bright O-type stars.
Clarke D., McDavid D., Smith R.A., Henrichs H.F.
<Astron. Astrophys. 383, 580 (2002)>
=2002A&A...383..580C 2002A&A...383..580C
ADC_Keywords: Stars, O ; Stars, bright ; Polarization
Keywords: polarization - stars: early-type - stars: individual: ξ Per -
stars: individual: λ Cep - stars: individual: 68 Cyg
Abstract:
Polarimetric data associated with multi-parameter observational
campaigns of selected bright O-type stars and their variable winds,
are analysed in relation to the outcomes of the UV and optical
spectroscopic studies. For the stars ξ Per and λ Cep,
individual measurement uncertainties are Δp~±0.0002 with
nightly mean uncertainties of Δp~±0.00007. Although
variability is apparent on a night-to-night basis, with differences in
Δp∼0.0002, no correlations are found between these and the
periodic behaviours associated with the stellar SiIV and Hα
lines.
Objects:
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RA (2000) DE Designation(s)
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03 58 57.9 +35 47 28 xi Per = HR 1228
22 11 30.6 +59 24 52 lambda Cep = HR 8469
21 18 27.2 +43 56 45 68 Cyg = HR 8154
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablev.dat 64 48 Polarimetric data (V-band) from the 1991 October
campaign for ξ Per, λ Cep and 68 Cyg
tableb.dat 64 125 Polarimetric data (B-band) form the 1989 October
campaign for ξ Per and λ Cep
tables.tex 77 249 LaTeX version of the tables
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See also:
J/A+AS/116/257 : Variability in O-stars wind (Kaper+, 1996)
Byte-by-byte Description of file: tableb.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Star Star name (1)
14- 25 F12.4 d HJD Heliocentric Julian date
28- 33 F6.3 % q Normalised Stokes parameter, q
35- 40 F6.3 % u Normalised Stokes parameter, u
42- 46 F5.3 % p(B) Degree of polarization
48- 52 F5.3 % e_p(B) rms uncertainty on p(B) (G1)
54- 59 F6.2 deg theta Vibration direction, θ relative to the
standard equatorial frame
61- 64 F4.2 deg e_theta rms uncertainty on theta (G1)
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Note (1): For ξ Per, data measured in the B-band (with the addition
of a 10% neutral density filter)
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Byte-by-byte Description of file: tablev.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Star Star name
14- 25 F12.4 d HJD Heliocentric Julian date
28- 33 F6.3 % q Normalised Stokes parameter, q
35- 39 F5.3 % e_q rms uncertainty on q
41- 46 F6.3 % u Normalised Stokes parameter, u
48- 52 F5.3 % e_u rms uncertainty u
54- 58 F5.3 % p(V) Degree of polarization (G1)
60- 64 F5.3 % e_p(V) rms uncertainty on p(V)
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Global Notes:
Note (G1): Estimates for the uncertainty of the p(B) and θ based on
the photon count associated with the individual measurement set.
Acknowledgements: David Clarke
(End) Patricia Bauer [CDS] 20-Dec-2001