- Radio and Electrical Engineering Division, National Research Council, Ottawa, Canada.
- Centre for Research in Experimental Space Science, York University, Toronto, Canada.
THE source VRO 42.22.01 (BL Lac) has interesting and unusual properties at both radio and optical wavelengths. The radio object was first discovered during a source survey at 610 MHz (ref. 1). It was studied in further detail at centimetre wavelengths by J. M. M. and B. H. A.2, who delineated the spectrum, and identified the source with an optical object. Schmitt3 noted that the optical object was catalogued as BL Lac and listed as a variable star. But the true nature of the object is uncertain. It is a rapid optical variable and its spectrum shows no emission or absorption lines (unpublished work of T. D. Kinman, E. Harlan and E. Marosan, and of D. DuPuy, J. L. Schmitt, R. McClure, S. van den Bergh and R. Racine). At optical frequencies there is about 10 per cent linear polarization4. Radio observations by Biraud and Veron5 indicated that the source was variable at a wavelength of 11 cm, and was circularly polarized.
- 1 - general ; 2 - general science & technology ; 3 - general science & technology
- 1 - sciences appliquees, technologies et medecines ; 2 - sciences biologiques et medicales ; 3 - sciences biologiques fondamentales et appliquees. psychologie ; 4 - invertebres