Next entry: Test of the Argo Navis

Previous entry: Sunspots 661, 662, 663, 664 and 665

Sunspot group 667

On September 4 2004 I observed the sunspot group 667 from 08:00 UT until 10.30 UT with the four inch refractor, the Baader ND5 full aperture filter, and three other Baader filters, the Fringe Killer, Continuum and Contrast Booster. Again with a

magnification of 33x (Plossl 32mm) the granulation of the Sun was visible at once. On the eastern half of the Sun (left of the image below) sunspot 667 was visible with a huge area with faculae between the sunspot and the eastern limb of the sun. At higher magnifications (80X to 100x with Vixen Lanthanum eyepieces 12mm and 10mm) the big sunspot of group 667 seemed to bet into 4 pieces by three light-bridges. A hint of these light-bridges can be seen on the detailed (green) image of the Sun.

The overview image below was shot with the TAL 100RS 4 inch refractor and a 32mm Televue Plossl eyepiece, Nikon Coolpix 4500 and the following settings: 1600x1200, Image Quality: fine, shooting mode S, Focus Mode: Auto, shutter speed 1/250, aperture 3.8, ISO 100, optical zoom 2x, matrix metering. Filters: IR/UV cut, Fringe Killer, Contrast Booster and full aperture Baader ND5 Solar Screen.

image

The image was stacked out of 20 images using Keith’s Image Stacker. With Photoshop unsharp masking was set to 192% (amount) and 3.0 pixels (radius), contrast +12, brightness -7.

On the detailed image below you can see the largest member of sunspot group 667 with the faculae between the sunspot and the sun’s limb. You can also see the granulation. You can also see a hint of the three light-bridges that cut the umbra of this sunspot into 4 parts. I couldn’t get a better image, but visually these light-bridges where very easy to detect. 

The detailed image below was shot with the TAL 100RS 4 inch refractor and a 15mm Vixen Lanthanum eyepiece, Nikon Coolpix 4500 and the following settings: 1600x1200, Image Quality: fine, shooting mode S, Focus Mode: Auto, shutter speed 1/60 aperture 5.1, ISO 100, matrix metering. Filters: Baader continuum filter and full aperture Baader ND3.8 Solar Screen.

The image was stacked out of 19 images using Keith’s Image Stacker. The image was processed using Keith’s Image Stacker with the following settings: align 3, sort by difference, laplacian pyramid sharpen 1:67, 2:25, 3:41, 4:19, 5:8, 6:3, DC:1, Cutt-off:0. Adjust histogram levels: black 1270-4950.

image

Posted by Math on 10/16 at 08:09 AM
Solar log • (0) TrackbacksPermalink