Next entry: Sunspot group 667

Previous entry: Some great doubles revisited

Sunspots 661, 662, 663, 664 and 665

On August 22 I observed the Sun for an hour from 14.15 UT till 15.15 UT. For visual observing I used the 4 inch TAL refractor with a full aperture ND 5 Solar Screen, the Fringe Killer and the Contrast Booster.  Before shooting the images I added

the IR/UV cut filter. At 32x the suns granulation is at its best. It can be seen all across the surface of the sun. As you can see on the image below, there are 5 major groups of sunspots visible. In 661, the biggest sunspot visible, a lightbridge is clearly visible.

The image below was shot using the TAL 100RS, Baader ND 5 full aperture solar screen, the Baader Fringe Killer, IR/UV filter and Contrast Booster, and a 25mm Vixen Lanthanum eyepiece. The image is stacked out of 30 images that where shot with the Nikon Coolpix 4500 and the following settings: image quality fine, shooting mode S, focus mode Auto, shutter speed 1/500, aperture f 2.7, ISO 100, optical zoom 1, Metering matrix.

The 30 images where stacked, using Keith’s image stacker with the following settings: align 3, sort by difference, unsharp masking with radius 5 / intensity 10.4 and cut-off 0, adjust histogram levels red 0-8593, green 0-8121, blue 0-8256.


Posted by Math on 10/09 at 10:28 AM
Solar log • (0) TrackbacksPermalink