The use of an RTC XX 1390 second-generation intensifier (which consists of a S20R photocathode, a micro-channel plate and a screen) was described. In visual work, very faint objects become visible. Photographically, an 18th-magnitude object has been detected through a layer of cirrus. The effective focal length used was 20 m, giving a resolution of 1 arcsecond, thanks to the short exposure times needed. With a Celestron C8 telescope, the coma of Comet Halley was photographed with 2-second exposures, allowing transitory phenomena to be detected. Used in conjunction with video techniques, high time-resolution images could be obtained, opening up the possiblity of new forms of observation of faint objects.
KeywordsData Collection Exposure Time General Electric Focal Length Visual Observation
- 1.Caron, R., Koutchmy, S., Sarazin, M.: “A study of disconnection velocities in the plasma tail of P/Halley”, paper presented at this ColloquiumGoogle Scholar
- 2.Maley, P.D.: “Achievements in astronomical video data collection”, paper presented at this ColloquiumGoogle Scholar
- 3.Dahlmark, L., “Searching for variables, and constructing a slit-less spectroscope”, paper presented at this ColloquiumGoogle Scholar
- 4.Midavaine, T.: in Astronomie: le guide de l’observateur, ed. Martinez, P., Vol. 2, Chap. XIX, Paris, 1987Google Scholar
- 5.Mauro, J.A., ed.: Optical Engineering Handbook, General Electric Co., Syracuse, N.Y., 1966Google Scholar
- 6.Midavaine, T.: Observations et travaux, in press.Google Scholar