Polarization measures of 293 stars in Aquila.

Abstract

view Abstract Citations References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Polarization measures of 293 stars in Aquila. Gossner, Joseph L. Abstract Photographic polarization measures of faint stars were made with the ~6-inch refractor for the study of galactic structure in Aquila. The method of measuring polarization, using calcite, is that described by Markowitz.1 Two hundred and ninety-three stars were measured in a field 50 minutes of arc in diameter centered on the star HD231564. This star, which occurs on the edge of a dark cloud, is listed by Popper as c Bi with the high color excess Ei = +0.58 mag. It shows a polarization of 3.5 per cent ~0.2 in position angle 1350 ~ 3. The other stars give the following results: Mean lflp Polarization Angle a 11.5-12.5 i.2%+o.15 II9~+2 45 12.5-13.5 1.9 +0.15 ii8 +2 105 13.5-14.5 i.8 +0.15 120 +2 142 The magnetic vector for these three groups is within a degree of being perpendicular to the galactic equator. By percentages we get the following results: Mean Polarization Polarization Angle a ~i.5o% o.6% 114 93 1.51t02.50 i.8 121 104 >2.51 2.9 120c 95 It appears that at least two-thirds of the stars in this one-half square degree field are polarized more than 1.5 per cent. The estimated distances of the polarized stars are about a kiloparsec. Additional information on the colors and spectra of some of the polarized stars would serve to fix the distance of the polarizing cloud. Plates of two nearby regions, one clear and the other heavily obscured, have been secured for future study. I.A. J. 56, 134, 1951; 55, 175, 1950. 2.Ap. J. III, 495, 1950. U. S. Naval Observatory, Washington, D. C. Publication: The Astronomical Journal Pub Date: April 1952 DOI: 10.1086/106784 Bibcode: 1952AJ.....57R..11G full text sources ADS |