Bibcode
Oudmaijer, R. D.; Palacios, J.; Eiroa, C.; Davies, J. K.; de Winter, D.; Ferlet, R.; Garzón, F.; Grady, C. A.; Collier Cameron, A.; Deeg, H. J.; Harris, A. W.; Horne, K.; Merín, B.; Miranda, L. F.; Montesinos, B.; Mora, A.; Penny, A.; Quirrenbach, A.; Rauer, H.; Schneider, J.; Solano, E.; Tsapras, Y.; Wesselius, P. R.
Bibliographical reference
Astronomy and Astrophysics, v.379, p.564-578 (2001)
Advertised on:
11
2001
Journal
Citations
107
Refereed citations
100
Description
This paper presents optical UBVRI broadband photo-polarimetry of the
EXPORT sample obtained at the 2.5 m Nordic Optical Telescope. The
database consists of multi-epoch photo-polarimetry of 68
pre-main-sequence and main-sequence stars. An investigation of the
polarization variability indicates that 22 objects are variable at the
3sigma level in our data. All these objects are pre-main sequence stars,
consisting of both T Tauri and Herbig Ae/Be objects while the main
sequence, Vega type and post-T Tauri type objects are not variable. The
polarization properties of the variable sources are mostly indicative of
the UXOR-type behaviour; the objects show highest polarization when the
brightness is at minimum. We add seven new objects to the class of UXOR
variables (BH Cep, VX Cas, DK Tau, HK Ori, LkHα 234, KK Oph and RY
Ori). The main reason for their discovery is the fact that our data-set
is the largest in its kind, indicating that many more young UXOR-type
pre-main sequence stars remain to be discovered. The set of Vega-like
systems has been investigated for the presence of intrinsic
polarization. As they lack variability, this was done using indirect
methods, and apart from the known case of BD+31o643, the
following stars were found to be strong candidates to exhibit
polarization due to the presence of circumstellar disks: 51 Oph,
BD+31o643C, HD 58647 and HD 233517. Table A1 is only
available in electronic form at the CDS via anonymous ftp to
cdsarc.u-strasbg.fr (130.79.128.5) or via
http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/379/564