X-Sender: cidadao@mail.telepac.pt
Date: Tue, 02 Jan 2001 15:31:01 +0000
From: Antonio Cidadao <a.cidadao@mail.telepac.pt>
Subject: Jupiter data (Dec30 and Jan1)

Hello all,

Hope you had a nice beginning of the new millenium!

I'm attaching the last images obtained on 2000 (Dec 30) and the first of
the current year (Jan 01). In the following messages I will send some more
December data (22, 26, 27 and 28). 

These last days the weather has been very unstable, with intermitent rain
periods and strong winds. Seeing has not been favourable, but I have been
oppening (and closing the rooftop) to at least get some images.

Besides RGB images, from Dec 22 I started to obtain broadband IR (830nm and
up; in practice until 950nm due to CCD response) and UV (peak at 355nm;
320-390nm) images. 

These filters are used externaly to the CCD camera, in combination with the
"clear filter" of the camera's internal RGB filter wheel. As a control, I
confirmed that the image disappears when the UV filter is used in series
with the B filter (392-508nm), and the IR filter is used in series with the
R filter (612-670nm). 

Imaging with the IR filter is very easy, and pictures are contrasty as
expected. With my setup and good transparency, 15sec raws are necessary to
originate half-filled pixels but 1sec is enough for correct focusing.

The UV filter is more difficult, with unbinned raws of 45sec giving rise to
pixel levels of about 4000 (with good sky transparency; filled pixels =
32767). However, the correcting plate of the 10" LX200 and the VERY low
response of the ST5C in the UV can explain this. Focusing is OK with 5sec
integrations.

The images I'm sending now show the GRS, the 3 clustered SSTB ovals (its
position keeps on changing) and the EZs/SEBn disturbance.

Regards and good observations

Antonio