DSS images/P126 (Pluto occn)

Bill J Gray Jul 22, 2002

Hi folks,

Paul Lecko asked:

"...When I edited out those little DSS images, they left behind
'empty white frames'."

Errmmm... just out of curiosity, how did you "edit them out"?
I didn't think there was a way to do that. (Guide decompresses those
FITS files into the Guide directory on an as-needed basis. If you
delete them, Guide just extracts them all over again.)

The only way I can see to edit them out, leaving no frame, is
a somewhat tedious one. Guide gets data for the images from files
IMGDA000.IDX through IMGDA127.IDX. These 128 files list the images
in given chunks of the sky, each covering about 1/128 of the entire
celestial sphere. These files, too, are copied on an as-needed
basis to the Guide directory; delete them, and Guide will re-create
them. But if you convert these files to empty ones, or files
containing some meaningless text, Guide won't draw anything.

Not an appealing method, I realize. I'll add some sort of
"suppress built-in DSS images" control.

Roger, about the P126 occultation: this isn't a double star
catalog. It is the 126th entry in a list of stars to be occulted
by Pluto. If you go into "Tables... Miscellaneous Tables" and
select "Pluto and Charon occultations", you will see this event
listed. However, it's listed as C126, not P126; at the time the
event was originally computed, it was thought that _Charon_ would
be occulting this star, not Pluto.

I've seen one report (on the Minor Planet Mailing List) that
this event was recorded from two stations in northern Chile.

-- Bill