Crimean Astrophysical Observatory
HiDHN solar images

detailed region The Crimean Astrophysical Observatory is located on the Crimean Peninsula in the country of Ukraine (large map), at a longitude of 34°1'E and a latitude of 44°32'N. The CrAO is situated between Simferopol and Bakisaraj, and to the North-West of the resort city of Yalta. (see detailed area) Much of Crimea experiences very mild temperatures in the summer time, which makes CrAO a good observing site.

The images obtained from the Crimean Astrophysical Observatory, are taken using a similar observing system utilized at Mt. Wilson. The primary difference is the size of the camera chip at 649x493 pixels. Compared to the 1024x1024 chip used at Mt. Wilson, the CrAO image is 1/4th the size and resolves only 1/2 as much solar detail. Images are acquired by integrating the focused image of the sun over three seconds at a frequency of 30Hz, for a total of 90 images. One of the limitations of this method is the long exposure necessary to build up the solar image. Atmospheric seeing can disturb the image of the sun over longer exposures, causing blurring and decreased resolution. A future upgrade to the system in Crimea will be the installation of a 1024x1024 pixel 12-bit camera. This will bring the resolution of solar images at Crimea up to the same resolution of images being acquired at Mt. Wilson. Both sites use a sodium-magneto-optical-filter

Below, you will find a sampling of images from Crimea for May 12, 1996. May 10th was the official beginning of image-acquisition for summer 1996 at CrAO, and May 12th was the first day of overlap for both sites. Both sites can observe the sun at the same time, for up to 2 hours, during May through August. The images below are presented as a comparison of features seen on the sun from two separate locations. In all images, north is at the top, and west is to the right.

There is now a mirror site available for the Crimean Astrophysical Observatory at
and a link to the HiDHN portion of the joint project at

Sample Comparisons of CrAO-MtW Images

FiltergramMagnetogram DopplergramVelocity Map
May 12, 10:53 UTMay 12, 10:53 UT May 12, 15:10 UT15:10 - 15:13UT
Mt. Wilson
60' Tower
May 12, 14:30 UTMay 12, 14:30 UT May 12, 15:10 UT15:10 - 15:13UT
low res - 43K low res - 19K med res - 172K
high res - 77K high res - 70K high res - 318K

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