We are observing at Palomar with the 200-inch Hale telescope, using a 7.9 micron imaging spectrometer in imaging mode and a 256x256 InSb at 2.35 microns. We began observing with the imaging spectrometer at around 02:35 UT and with the InSb camera at around 03:05 UT. We have not seen anything as of 03:55 UT.
Continuing observations with TIMMI at 9um on the 3.5m telescope and IRAC 2B at 2.2um on the 2.2m at ESO La Silla show that nothing was seen over the predicted impact site B up to 3:35UT, 17 July. Conditions were not ideal but this is a strong indication of differences between the A and B impacts.
Richard West & Richard Hook, ESO Garching
We obtained a sequence of images every 10 seconds from 2:44 to about 3:25 UT, of Jupiter at 1.7 microns (till 3:12) and 2.3 microns (thereafter), and saw nothing unusual at all on Jupiter's limb. Predicted impact time was 2:54. Clouds rolled in after 3:25.
John Spencer, Darren DePoy, OSIRIS, CTIO 4-meter.
Observations using a NICMOS2 array and a NICMOS3 spectrometer were obtained at approx. 0hr U.T. of the A impact site which was clearly visible at 2.2um. A spectrum of the impact site from 2.0-2.4um at R=1600 was obtained with the impact site clearly distinguishable from the remainder of the impact latitude. Observations from 02:40 U.T. through 03:30 U.T. showed nothing from the B impact site in either 2um images or spectroscopically. In other data we have acquired after the A impact but before B we observed the H2 auroral emission to be much weaker than in March at the same system III longitude.
George and Marcia Rieke, Milagros Ruiz, Chad Engebracht, Pat Frawley, Dave Wittman Steward Observatory 90-inch, Kitt Peak
We observed Jupiter from 02:35 to 4:02 UT with 2 narrow band filters centered at 2.22 and 2.36 microns with a 1 - 2.5 imaging camera on the Apache Point Observatory 3.5 m telescope. We see no evidence of any consequence of the B impact. This instrument is the second generation of the SPIREX camera at the South Pole which reported a positive detection of A in the same filter.
New Mexico State
Report from W. M. Keck Observatory, Mauna Kea, Hawaii: Impact B.
We observed impact B in a narrow band L band (3.27-3.44 micron); the plume was faint, but clearly detected at the expected position, starting at 02:56, fading at around 3:13.
Imke de Pater, James Graham, Garrett Jernigan and collaborators.
Monitoring the H3+ ionospheric lines at 3.5 microns with CGS4 echelle spectrometer on UKIRT, Mauna Kea, Hawaii, we saw a fivefold brightening of the emission around the time of impact of fragment B (around 2:50 UT) on the east limb of Jupiter. The spectrometer slit was approximately aligned on the nominal impact latitude. This faded over 90 minutes.