Abstract
A variety of spectroscopic observations have now been made at Royal Greenwich Observatory using a Spectracon, which is a single-stage magnetically focused image tube with a thin mica output window. When used with highly corrected optical systems and a fine-grained nuclear emulsion, the image tube provides an efficient, high resolution linear detector giving a low noise record.
The principles and practice of operation are briefly described, and results are presented which demonstrate how some of the advantages of electronography can be exploited in stellar spectroscopy.
Notes
Summary of paper presented at a Symposium on “Photography in Astronomy” organized by the Scientific and Technical Group of The Royal Photographic Society on 8 December 1975 in London. MS received 20 February 1976