THE STELLAR INTERFEROMETER AT NARRABRI.
Abstract
The interferometer at Narrabri makes use of an intensity interferometer to achieve a max resolution of approx 0.0005 sec of arc. It is designed to measure the apparent angular diam of all stars brighter than magnitude +2.5 and with spectral type earlier than F. O. The instrument consists of 2 large mirrors 22 ft in diam which move on a circular track 618 ft in diam. The mirrors are controlled by a computer to follow the chosen star in azimuth and elevation. At the focus of the 2 mirrors there are photomultipliers which view the star through narrow-band interference filters. The output currents of the 2 photomultipliers are carried by coaxial cables to an electronic correlator which amplifies the fluctuations in the 2 currents in the frequency range 10-120 mcps and multiplies them together to measure their correlation. In operation the correlation is measured as a function of the separation between the 2 mirrors. A single observation at 1 spacing requires approx 3 hr for a star of magnitude +1.0. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1964
- Accession Number
- AD0614536
Entities
People
- R. Hanbury Brown
Organizations
- University of Sydney