Optical polarization measurements in W3 and M17.
Abstract
Results are reported for UBV photopolarimetric observations of 77 stars in W3 and 52 stars in M17 as well as for UBVRI photoelectric photometry of 15 stars in the western region of W3. It is found that the polarization is as high as 16% in W3 and 29% in M17, that the polarization angles in W3 are aligned parallel to the general interstellar magnetic field, and that the polarization angles in M17 are aligned parallel to the large increment in the visual brightness distribution on the western side of the nebula. It is suggested that the corrected intrinsic foreground extinction in W3 and M17 is most probably produced by circumstellar matter or by dust embedded in hot H II regions.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- March 1978
- Bibcode:
- 1978A&A....64L..13S
- Keywords:
-
- Cosmic Dust;
- Polarimetry;
- Polarization (Waves);
- Stellar Radiation;
- Electrophotometry;
- H Ii Regions;
- Interstellar Extinction;
- Interstellar Magnetic Fields;
- Stellar Evolution;
- Ubv Spectra;
- Astrophysics;
- H II Regions:Polarization