Saturday, June 25, 2005

Silent Sun: 2005-06-25

After raining for half a month, we got the sun today, in a relatively clear sky.

However, the sun is dead silent today, nearly nothing on the surface, no sunspot, no active region. Binoviewer still reveal many subtle detail but those were hard to capture and align during stacking.

Few prominence but does not worth to capture.

Tuesday, June 14, 2005

June 11 Solar Observation and Imaging

A big Hedgerow (prominence) is in view, very impressive with binoviewer. AR775 and 776 is nice as well. Found a new way to use LXD55 inside home, this is to use it without polar alignment, to point it straight out from the window and then hand track, by doing so, the scope will be able to hang outside, since the window is SW facing, track can mostly done by pressing the RA only.

This is also the first time that I was able to capture some decent high resolution solar disc detail. I used a 2x barlows and I believe that 3x could be used too. The exposure time is 1/1000s with 20-30% gain. So, there're still room for pushing further. It's just f/24 and I believe f/36 could be nice by over-sampling a bit, it should not be a problem on the ToUCam.

A b/w webcam should be even better, but anyway, the investment is not very much like I wanted at the moment. So, I will stick at 2x2 mosaic at high resolution. Whole solar disc will be using a DSLR which will be purchased probably next month, after the D50 is released (hopefully the price of 350D will be pushed downward further).

If I were to play mosaic for full solar disc, I will probably need to write a software to track and to aid positioning the telescope, solar disc hardly has enough landmark to let me frame accurately to make a mosaic that large. Maybe spend time to study ASCOM.

Prominence turn out to be easily captured, also got a photograph on that day.

Both solar disc image and prominence has a very narrow correct exposure range, due to the narrow dynamic range of the webcam, especially for the sun.

I'm happy with the result. Should try to further process that short video clip, and probably to play false color with yellow/orange instead of currently orange/black.

Thursday, June 09, 2005

"Discover" double shadow transit again

Discover doubls shadow transit on Jupiter again yesterday night with my C8 at low power (13mm Nagler) with an altazmount. can't go higher power... it's so subtle and part of the aperture is blocked... this time it's special since a shadow is on top and another one is on the middle. :-)

cannot really capture it since when Jupiter is in better position, it's already finished... too tired to buy the setup out to shoot, so bad.