Tue Jul 19 09:57:29 1994

National Solar Observatory/Sac Peak Data

A new night-time guider at the National Solar Observatory at Sacramento Peak has facilitated observations of Jupiter during the SL9 encounter. Our program images the entire Jovian disk in the near-IR methane bands at 750 and 890 nm and nearby continuum at 725 and 950nm. Simultaneous visible continuum exposures at 500nm will allow destreching of the near-IR methane image for better continuum subtraction. We cycle through all the filters every 36 seconds. Near-IR J-band images with a 256x256 NICMOS chip are also taken at a rapid cadence of 1 per 3 seconds.

Unusually bad weather prevented observations until 02:20 UT on 19 July. We obtained a four hour run from 02:20 until 06:37 UT. We tracked Jupiter and obtained reasonable data until it was only 5 degrees above the horizon. Though cirrus was present, the data are of good quality. Sample images and mpeg movies will be available on our WWW site:

http://www.sunspot.noao.edu/index.html

The time series are being analyzed to study the morphology of the G impact site and to search for evidence of wave phenomena. We have observed Jupiter at these wavelengths during the day and hope to obtain data of the impending L impact.