Pascal Hilkens Astro Home Page
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.
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
Black Eye Galaxy Messier M64
A couple of degrees west from M53, in Coma Berenices, you can observe the spiral galaxy "Black Eye" or Messier M64 (NGC 4826). It's located at a distance of 13,5 million light years from Earth. Visualy, the "eye" can clearly being seen with a 30cm dobson and even the spiral arms are visible.
The picture is taken using Nikon D7500 on TAL200K. Pictures are stacked using Deepskystacker.
The picture is taken using Nikon D7500 on TAL200K. Pictures are stacked using Deepskystacker.
Messier M3
Globular Cluster Messier M3 (NGC5227) in Canes Venatici is located at a distance of 32.000 light years from Earth.
Pictures were taken (May 7th, 0h57UT) with Nikon D7500 on TAL200K. In total 10 pictures each 30s and ISO3200 are stacked using Deepskystacker. Final editing with CS4.
Pictures were taken (May 7th, 0h57UT) with Nikon D7500 on TAL200K. In total 10 pictures each 30s and ISO3200 are stacked using Deepskystacker. Final editing with CS4.
Wednesday, May 9, 2018
Kemble 2 - Mini Cassiopeia
the ‘W’ of his bigger brother Cassiopeia. The stars that shape this figure are all of magnitude 7 and 8. Kemble 2 is best seen through large binoculars or small telescopes with a low magnification. You can find Mini-Cassiopeia between υ en χ Draconis in constellation Draco.
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