Even though the seeing was poor I put my scope outside to observe the Great Red Spot (GRS). The passing of the GRS was around 20h30 UT. My observation was completed around 21h30. I used my ASI224MC camera with barlow x2 on TAL200K f/8.5. Pictures are stacked using AutoStakkert and final editing with CS4.
Pascal Hilkens Astro Home Page
Tuesday, May 15, 2018
Monday, May 14, 2018
Sunday, May 13, 2018
Sunflower Galaxy Messier M63
Sunflower Galaxy Messier M63 (NGC 5055) in constellation Canes Venatici is located about 23,5 million light years from Earth. This picture was taken using Nikon D7500 with TAL200K and stacked by DeepskyStacker. Final editing completing with CS4. Total of 18 pictures and a combined exposre time of 550 seconds.
Saturday, May 12, 2018
Virgo Clsuter M84 M86
Circumscribed and 22° Halo around the Sun
Today, around midday, the Sun was seen with a 22° Halo and adjacent a Circumscribed Halo. Both Halo's have the red color towards the center of the Sun.
The 22° and Circumscribed Halo's are developed when Sun light enters one side of a hexagonal columnar ice crystal and exits through another side. The light is refractec when it enters the ice crystal and once again when it leaves the ice crystal. The difference between both Halo's is the fact that 22° Halo are formed within random distributed crystals and Circumscribed Halo's when the crystals are merely horizontal oriented.
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White = 22° Halo / Blue = Circumscribed Halo |
The shape of the Circumscribed Halo also changes depending the height of the Sun at the sky. When the sun is low, the two “arms” of the upper tangent arc form a sharp angle. As the sun gets higher, they get closer and closer to the 22°-halo. At the same time they become longer, joining the lower tangent arc at a sun elevation of 32°. The complete ring now being formed is called the circumscribed halo. It touches the 22°-halo above and below the sun. First the circumscribed halo is of an oval shape. At increasing sun elevations its shape becomes more and more circular and gets closer to the 22°-halo. At a sun elevation of 70° the circumscribed halo almost covers the 22°-halo.
Friday, May 11, 2018
Globular Cluster NGC 5466
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