SAAO Observations: S, U
Jeff Shykula of RPI used the 1.9 m telescope and infrared photometer for high-speed K-band photometry of the impact of fragment S. Definite brightening began at about 15:22 UT, with peak brightness at about 15:29 and a return relatively constant signal levels by 15:37. Peak brightness was nearly twice that seen for Q1, with a peak K magnitude of about 1.19.
Kaz Sekiguchi of SAAO used the 0.75 telescope and PtSi camera to obtain images of Jupiter at 30-second intervals during the impact of fragment S. A low-level brightening began at about 15:16 UT, and began to fade before a much more dramatic brightening began at about 15:22. Peak brightness occurred at 15:29-15:30 and by 15:40 there was definitely no remaining obvious excess brightness from this impact. The bright spot at the impact site could not easily be separated from those for impacts R, G, and D.
This impact plume was also considerably brighter than that seen at the impact of fragment H.
K-band images and high-speed photometry around the expected time of impact for fragment T showed no obvious brightening before 19:00 UT. Detection of low-level brightening was made difficult by bright spots at the limb, however. Attempted U-band high speed photometry of Jupiter for this impact by Peter Martinez of the University of Cape Town also showed no detection for the fragment T impact.
No observations are planned for fragment U, as the airmass will be high and the expected brightening small.
Impact observations at Sutherland have now been completed, with no "clouded out" events at all.
Various images are available in either of these anonymous ftp accounts:
System name IP number Directory ----------- --------- --------- ftp.ru.ac.za 146.231.128.1 /pub/saao/images kudu.ru.ac.za 146.231.128.5 /pub/saao/imagesThe images are in GIF format.
Dave Laney