Contents
Images
Upload your image
DSS Images Other Images
Related articles
The Keck Aperture-masking Experiment: Near-Infrared Sizes of Dusty Wolf-Rayet Stars We report the results of a high angular resolution near-infrared surveyof dusty Wolf-Rayet stars using the Keck I Telescope, including newmultiwavelength images of the pinwheel nebulae WR 98a, WR 104, and WR112. Angular sizes were measured for an additional eight dustyWolf-Rayet stars using aperture-masking interferometry, allowing us toprobe characteristic sizes down to ~20 mas (~40 AU for typical sources).With angular sizes and specific fluxes, we can directly measure thewavelength-dependent surface brightness and size relations for oursample. We discovered tight correlations of these properties within oursample that could not be explained by simple spherically symmetric dustshells or even the more realistic ``pinwheel nebula''(three-dimensional) radiative transfer model, when using Zubko's opticalconstants. While the tightly correlated surface brightness relations weuncovered offer compelling indirect evidence of a shared and distinctivedust shell geometry among our sample, long-baseline interferometersshould target the marginally resolved objects in our sample in order toconclusively establish the presence or absence of the putativeunderlying colliding-wind binaries thought to produce the dust shellsaround WC Wolf-Rayet stars.
| Radial velocity measurements. IV - Ground-based accompaniment to the HIPPARCOS observation program The paper presents 396 radial velocities of stars distributed in 19fields of 4 x 4 degrees. The study employs the Fehrenbach objectiveprism method and the same measuring technique used in a previous paper(Fehrenbach et al., 1987).
|
Submit a new article
Related links
Submit a new link
Member of following groups:
|
Observation and Astrometry data
Constellation: | はくちょう座 |
Right ascension: | 20h19m26.77s |
Declination: | +45°12'54.1" |
Apparent magnitude: | 7.712 |
Distance: | 189.036 parsecs |
Proper motion RA: | 7.1 |
Proper motion Dec: | 7.3 |
B-T magnitude: | 9.085 |
V-T magnitude: | 7.826 |
Catalogs and designations:
|