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Sun AR1476, Venus Crescent

Posted: 12 May 2012

Friday morning, 11 May 2012, was clear so I decided to check out the large sunspot group AR1476. The observatory was opened at 0933 MST, 89°F. I attached the Orion full aperture solar filter to the 8" LX200-ACF and mounted the Coronado PST piggyback on the 8". At 0945 MST, got my first look at AR1467 in the 8", 77X. A very impressive sunspot group, with lots of details seen. The view was even better at 133X. Although seeing was not ideal, the view at times at 206X was good. I then took a look through the PST Hydrogen-Alpha solar telescope, 32X. Wow! Quite a view: 9 large prominences and many smaller ones were visible. AR1476 showed a lot of structure in H-Alpha. In fact, the entire solar disk was a great view in the PST. I switched to 41X on the PST; still good view.

I removed the PST from the 8" so that I could attach the D7000 DSLR at prime focus. I had to add the focal reducer in order to image the entire solar disk with the D7000. This is a slightly cropped image, prime focus + focal reducer, 1/500sec, ISO 200:


This is AR1476, uncropped, prime focus + 2X Barlow Lens, 1/500sec, ISO 3200:


I then did some iPhone 4 imaging of the sun. This is AR1476 taken with the Camera app, MX-1 afocal adapter, 77X, cropped:


While in the observatory, I edited the above photo on the iPhone using Adobe "PS Express" and tweeted the following image on Twitter:


I ended solar observing, and just before closing the observatory, swapped the rechargeable batteries in the Wireless AutoStar II. Only getting about 3 weeks from a charge.

Closed the observatory at 1055 MST, 96°F.

Re-opened the observatory Friday evening at 1815 MST, 94°F, for a short session to observe and photograph Venus. The sky was clear but there was a strong breeze blowing at times. Began observing Venus at 1824 MST, 77X. The crescent was noticeably thinner this evening than on previous evenings. The view at 206X was very nice. I set up for afocal imaging using the iPhone 4 and MX-1 afocal adapter. I imaged at 77X + moon filter, and 154X + moon filter. I did both single photographs and a video recording (45 seconds) using the Camera app. Atmospheric turbulence messed up the single exposures, but the video had many good frames. This is one frame from the video, cropped but otherwise unedited:


I stacked 1358 frames from the video using Keith's Image Stacker, with this result (cropped but not edited):


The stacked image provides a more natural look.

I then did some Venus observing at 412X + moon filter. The moon filter really helped to reduce the glare due to the planet's brightness, allowing a very nice view of the planet. The terminator was indistinct and fuzzy-looking, as expected since Venus has an atmosphere.

Closed the observatory at 1853 MST, 83°F.

Comments are welcome; use the Comments section below, or you can Email Me. Thanks.

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