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Posted by: Christian Jan 28 2008, 09:47 PM

Hello, Everyone!

As far as i found out, Voyager 2 observed Supernova 1987A using its UVS Instrument in July 1987. Could someone please let me know, where i can find these Data, e. g. a Graph of the Spectrum of the Supernova as observed by Voyager?

Additionally i found, that Voyager made Observations during the Impact of Shoemaker-Levy 9 on Jupiter back in 1994. Those showed no results, but could someone please let me know, where i can find these Data?

Many Thanks in Advance!


Christian

Posted by: Dominik Jan 29 2008, 12:57 PM

They observed the SL-9 impact on Jupiter? I've never heard of that, but it sounds interesting... Do you know what instruments have been used? Maybe the camera system?

Sounds interesting...

Posted by: Toma B Jan 29 2008, 01:12 PM

Well not THAT interesting .... even if they used cameras it would be hard enough to see Jupiter from behind Pluto's orbit not to mention chances to see comet impact...
I think that we are lucky that Hubble got fixed in time to watch the spectacular impact...

Posted by: ugordan Jan 29 2008, 01:17 PM

IIRC they used the UV spectrometer to try and observe the SL-9 impacts, but nothing was detected.

Posted by: tedstryk Jan 29 2008, 04:08 PM

The camera software had been deleted. Voyager-2 has always had receiver trouble, so they deleted software for operating the cameras, which weren't thought to be of further use, in order to make room for software to operate the spacecraft autonomously during its interstellar mission if it could no longer hear from earth. Voyager didn't have enough memory for both. Just in case, they did the same to Voyager-1 after it took its "looking back" view of the solar system. By the time the idea of using the Voyagers to view the collision came up, it was already too late to upload and test the camera software, not to mention the issue of funding. Given that Jupiter would be 2.5 pixels across for Voyager 2 and 2 pixels across for Voyager 1, it is questionable how much value those observations would have had scientifically. From what I remember at the time, there was a possibility that some some basic software to operate the cameras might have been sent on time, but it was deemed not worth the risk of deleting the long-term operating software, plus operating the spacecraft with untested software. The possible gains from Voyager ISS observations of the crash were not worth risking the interstellar mission.

Posted by: NGC3314 Jan 29 2008, 04:49 PM

I checked with Jay Holberg, who has been the custodian of the deep-sky data archive for the UVS. He and Ron Polidan did set up some observations (from memory, using Voyager 2). The spacecraft were in cruise mode with multi-week automatic sequences running, so it took several days to get pointed - with null results. They followed the supernova for some months, since some predictions called for a delayed UV brightening, but there was no detection from any of these observations. In hindsight, this fits with the longer-wavelength UV behavior, from IUE and Astron, which show that the deep UV flux drops precipitously with time immediately after the outburst. The Astron folks put up a nice plot of the SN's UV spectral evolution, easiest found from http://quake.stanford.edu/~crao/astron/astron.html.