scholarly journals ON THE INTRINSIC CONTINUUM LINEAR POLARIZATION OF CLASSICAL BE STARS DURING DISK GROWTH AND DISSIPATION

2013 ◽  
Vol 765 (1) ◽  
pp. 17 ◽  
Author(s):  
Robbie J. Halonen ◽  
Carol E. Jones
Keyword(s):  
Linear Polarization ◽  
Be Stars ◽  
Disk Growth

scholarly journals Polarization Measurements of Some Herbig Ae/Be Stars

1990 ◽  
Vol 140 ◽  
pp. 323-324
Author(s):  
S. K. Jain ◽  
H.C. Bhatt ◽  
Ram Sagar
Keyword(s):  
Linear Polarization ◽  
Wavelength Dependence ◽  
Be Stars ◽  
Polarization Measurements

We have measured the linear polarization of 8 bright Herbig Ae/Be stars in UBVRI bands. No unique wavelength dependence of polarization magnitude as well as direction is found in these measurements.

scholarly journals Recent Results from Ultraviolet and Optical Spectropolarimetry of Hot Stars

1994 ◽  
Vol 162 ◽  
pp. 219-229
Author(s):  
K.S. Bjorkman
Keyword(s):  
Linear Polarization ◽  
Optical Data ◽  
Time Variability ◽  
Be Stars ◽  
Circumstellar Envelopes ◽  
Polarization Data ◽  
Hot Stars ◽  
New Models ◽  
Be Star ◽  
The Continuum

The first comprehensive linear polarization data on hot stars covering the spectral range from 1500 to 7600Å are presented. These results are based on recent observations made with the Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE), combined with ground-based observations from the Pine Bluff Observatory. Implications of the data for models of the circumstellar envelopes of hot stars are discussed, with particular emphasis on the surprising results found for the rapidly rotating Be stars. In particular, WUPPE discovered that the continuum polarization in Be stars decreases into the ultraviolet, which was not predicted by models prior to the observations. Time variability in the optical data is also discussed. Possible interpretations of these results are examined in the light of recent new models for Be star disks.

scholarly journals Intrinsic Linear Polarization of Be Stars as a Function of v sin i

1976 ◽  
Vol 70 ◽  
pp. 277-277
Author(s):  
R. Poeckert ◽  
J. M. Marlborough
Keyword(s):  
Electron Density ◽  
Optical Depth ◽  
Electron Scattering ◽  
Linear Polarization ◽  
Apparent Difference ◽  
Be Stars ◽  
Intrinsic Polarization ◽  
Disk Model

The polarization of 48 Be stars has been measured in two bands near Hα with the aim of determining the relation between intrinsic polarization and v sin i. A technique developed by Poeckert (1975) is used to remove the effect of interstellar polarization. It is found that intrinsic polarization depends strongly on v sin i; stars with low v sin i having little or no polarization. We have calculated the i dependence of linear polarization for a disk model envelope and find that the polarization is proportional to τe sin2i when the disk is optically thin (τe is a characteristic electron scattering optical depth). A comparison of the observed relation between intrinsic polarization and v sin i, and that predicted for the disk model is illustrated. We find that an envelope with an electron density of ≤5 × 1011 cm−3 can account for the degree of intrinsic polarization observed in all the program stars. The fact that stars of low v sin i have little intrinsic polarization is evidence for the assumption that these stars are seen pole-on and that the envelopes around these stars are axi-symmetric. No apparent difference between pole-on stars and extreme Be stars was obtained.

Intrinsic linear polarization of Be stars as a function of V*sin(i).

1976 ◽  
Vol 206 ◽  
pp. 182 ◽  
Author(s):  
R. Poeckert ◽  
J. M. Marlborough
Keyword(s):  
Linear Polarization ◽  
Be Stars

scholarly journals Long-term Variability in Be-Star disks

2000 ◽  
Vol 175 ◽  
pp. 422-434 ◽  
Author(s):  
J.H. Telting
Keyword(s):  
Recent Work ◽  
Be Stars ◽  
X Ray ◽  
Be Star ◽  
Disk Growth ◽  
X Ray Binaries ◽  
Disk Loss

AbstractBe stars can switch between non-disk, gradual disk growth, disk-loss events, and shell-line phases. Many aspects of this Be phenomenon are still not understood. In this paper I review recent work on variability in Be-star disks, divided in four different topics: disk growth (Section 1), long-term V/R variations and global disk oscillations (Section 2), spectacular variations (Section 3), and, concisely, the disk variability in Be/X-ray binaries (Section 4).

scholarly journals International multiwavelength campaigns on short-term variability of OB stars: optical polarimetry

1994 ◽  
Vol 162 ◽  
pp. 530-531
Author(s):  
D. McDavid
Keyword(s):  
Optical Spectroscopy ◽  
Linear Polarization ◽  
Wide Band ◽  
Be Stars ◽  
Short Term ◽  
Ob Stars ◽  
Intensive Monitoring ◽  
Polarization Measurements ◽  
Ultraviolet Observations ◽  
Short Term Variability

From 1986 through 1992, wide-band optical (B or V filter) linear polarization measurements of eight Be stars and seven O stars were obtained simultaneously with ultraviolet observations from IUE and worldwide ground-based optical spectroscopy and photometry in a series of campaigns designed to study the short-term variability of these objects. Each campaign consisted of intensive monitoring of a few carefully chosen stars over a period of several days and nights, with the greatest possible continuity subject to the limitations of instrument scheduling, weather, and the longitudes of the observing sites.

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