Nonthermal Radio Emission from H-alpha-Emission Object
Abstract
E. R. Seaquist, David Dunlap Observatory; P. C. Gregory, University of British Columbia; and P. C. Crane, National Radio Astronomy Observatory, report the detection and subsequent observations of highly variable radio emission from object No. 433 in the list of H-alpha-emission objects by Stephenson and Sanduleak (1977, Astrophys/ J. Suppl. 33, 459). Observations at several frequencies were made with the NRAO 91-m telescope, NRAO interferometer and the Algonquin Radio Observatory 46-m telescope between 1977 Aug. 15 and 1978 June 30. Maximum and minimum 2.7-GHz flux densities were 1.42 +/- 0.10 Jy (1977 Oct. 4) and 0.52 +/- 0.03 Jy (1978 Feb. 24). Observations at 10.5 GHz on 1978 June 30 show possible variability (~ 20 percent) during a single day. The source is nonthermal (spectral index = -0.5) and has angular diameter less than 0".1 at 8.1 GHz. The radio source position is R.A. = 19h09m21s.33 +/- 0s.03, Decl. = +4o53'53".5 +/- 1".0. (equinox 1950.0). X-ray, optical and infrared observations are strongly urged.
- Publication:
-
International Astronomical Union Circular
- Pub Date:
- August 1978
- Bibcode:
- 1978IAUC.3256....2S