Re: 17P/Holmes dust structure

On Wed, 31 Oct 2007 10:09:19 +0000, Pete Lawrence
<pete.lawrence@xxxxxxxxxxx> wrote:

The tail needs a long exposure. I can pick it up with 5 minute ISO800
shots but it's very indistinct. 45 minutes (9x5 minute) of imaging on
the 29th recorded it with a lot of image stretrching.

Which I expected. But with an hour of exposure I still don't see it in
my data. It's possible it was less transparent last night than I
thought- I didn't make any measurements of transparency and it was very
dark.

Last night I took a number of 20 minute SXV-H9 shots and it's clearly
evident on each shot. I'll process and post these later.

I'll look forward to seeing them; I can compare the location to my own
data. One problem is that I'm working at a pretty long focal length, and
the coma is nearly as large as my FOV now, so any tail structure I catch
will need to be very close in. Having a bit of snow just now, but if it
clears up by tonight I might try the 300D again. Not as good data, but a
wider FOV and no blooming to worry about.


_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
.