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J/PASP/106/949      Multicolor polarimetry of Be stars      (McDavid, 1994)

Multicolor polarimetry of selected Be stars: 1990-93 McDavid D. <Publ. Astron. Soc. Pac. 106, 949 (1994)> =1994PASP..106..949M (SIMBAD/NED Reference)
ADC_Keywords: Stars, Be ; Photometry, UBVRI ; Polarization Abstract: Optical polarization data in the UBVRI filter system for eight bright northern Be stars are presented here as the continuation of a long-term monitoring project begun in 1984. There are no strong cases of night-to-night variability, and the only star showing unmistakable changes in polarization from year to year over the nine years covered by the program is Pi Aquarii. Even though the observed sample spans a wide range in spectral type, vsini, and degree of intrinsic polarization, the normalized wavelength dependence of the polarization is surprisingly similar for all of the stars. Analysis of the wavelength dependence of the variable polarization of π Aqr in terms of a simple equatorial-disk model suggests that changes in the circumstellar electron number density alone may be sufficient to account for the observations, but it is not clear what real physical mechanism is involved. Addresses: McDavid D. Limber Observatory, Timber Creek Road, P.O. Box 63599, Pipe Creek,Texas 78063 Explanatory Note: Tables 3-12 include data from two previous publications: McDavid, D. 1986PASP...98..572M and McDavid, D. 1990PASP..102..773M. Objects: ---------------------------------------------------------- RA (2000) DE Designation(s) ---------------------------------------------------------- 03 29 04.1 +59 56 25 2H Cam = HD 21291 16 20 38.1 -24 10 08 omicron Sco = HD 147084 00 56 42.2 +60 43 01 gamma Cas = HD 5394 01 43 39.4 +50 41 20 phi Per = HD 10516 04 08 39.5 +47 42 47 48 Per = HD 25940 05 37 38.6 +21 08 34 zeta Tau = HD 37202 15 58 11.3 -14 16 45 48 Lib = HD 142983 16 27 01.3 -18 27 21 chi Oph = HD 148184 22 25 16.5 +01 22 38 pi Aqr = HD 212571 23 01 55.1 +42 19 34 omicron And = HD 217675 ---------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1 44 8 Program Be stars table2 11 5 Filter system parameters table3 62 40 Polarization of 2H Cam (standard star) table4 62 40 Polarization of ο Sco (standard star) table5 62 40 Polarization of γ Cas table6 62 45 Polarization of φ Per table7 62 45 Polarization of 48 Per table8 62 45 Polarization of ζ Tau table9 62 45 Polarization of 48 Lib table10 62 45 Polarization of χ Oph table11 62 45 Polarization of π Aqr table12 62 40 Polarization of ο And
Byte-by-byte Description of file: table1
Bytes Format Units Label Explanations
1- 7 A7 --- Name Star name 9- 14 I6 --- HD HD (Cat. III/135) catalog number 16- 19 I4 --- HR BS (Cat. V/50) catalog number 21- 24 F4.2 mag Vmag Visual magnitude (BSC4, See Cat. V/50) 26- 40 A15 --- Sp Spectral type (1) 42- 44 I3 km/s vsini vsini (1)
Note (1): According to Slettebak, A. 1982ApJS...50...55S
Byte-by-byte Description of file: table2
Bytes Format Units Label Explanations
1 A1 --- Passband Filter system passband 3- 6 I4 0.1nm Wavelength Effective wavelength 8- 11 I4 0.1nm FWHM Bandpass
Byte-by-byte Description of file: table3 table4 table5 table6 table7 table8 Byte-by-byte Description of file: table9 table10 table11 table12
Bytes Format Units Label Explanations
1- 2 I2 --- Month Month of observations 4- 5 I2 yr Year-1900 Year (offset 1900) of observation 7 A1 --- Passband [UBVRI] Filter system passband 9- 10 I2 --- nobs []? Number of observations 12- 16 F5.2 % q []? Mean normalized Stokes parameter q 18- 21 F4.2 % e_q []? rms uncertainty on q 23- 27 F5.2 % u []? Mean normalized Stokes parameter u 29- 32 F4.2 % e_u []? rms uncertainty on u 34- 37 F4.2 % p Mean degree of polarization 39- 42 F4.2 % e_p []? rms uncertainty on p 44- 48 F5.1 deg theta Mean equatorial position angle 50- 53 F4.1 deg e_theta []? rms uncertainty on theta 55- 58 F4.2 % dpi []? Instrumental precision of q, u, or p (1) 60- 62 F3.1 deg dthetai []? Instrumental precision of theta (2)
Note (1): dpi = mean instrumental error in the degree of polarization for each set of measurements according to photon statistics, unless photon statistics gives a value less than 0.02%, in which case the error is approximated as 0.02% due to atmospheric scintillation for the 200-second integration time Note (2): dthetai = mean instrumental error in equatorial position angle of the polarization, based on the relation dthetai=28.65(dpi/p)
Origin: AAS CD-ROM series, Volume 3, 1995
(End) David McDavid [Limber Obs.] 12-Sep-1994, Patricia Bauer [CDS] 16-Feb-1995
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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