Precise Optical and Radio Astrometry of the Quasar 1928 + 728
Abstract
Precise optical and radio positions of the quasar 1928+738 have been obtained in the FK4 system from direct photography and VLA astrometry. In addition, for the first time, precise astrometric positions have been obtained from CCD frames related to the FK4 system by faint reference stars derived from the photographic plates. The coincidence of the radio and optical emission makes this source a suitable candidate for the establishment of an extragalactic reference frame by optical and radio astrometry of compact extragalactic sources.
- Publication:
-
The Astronomical Journal
- Pub Date:
- February 1987
- DOI:
- 10.1086/114308
- Bibcode:
- 1987AJ.....93..261D
- Keywords:
-
- Astrometry;
- Astronomical Photography;
- Quasars;
- Radio Spectra;
- Visible Spectrum;
- Charge Coupled Devices;
- Extragalactic Radio Sources;
- Reference Stars;
- Astronomy;
- QUASARS