Tuesday, August 14, 2012

Holiday hunting

August holidays in Różan let me made a few nice astrophoto sessions. Unfortunately only a few nights have been clear enough, and almost all of them ended with sudden fog attack. But nevertheless I did hunt some deep sky objects, although these targets were not especially demanding.
For the first clear night I did Dumbbell nebula (M27). It is easy target for visual observations, because this nebula is relatively bright and not so large in the same time. Its apparent diameter is 8 arc minutes, so it is like 1/4 of apparent Moon diameter. Nebula is placed somewhere in the space about 1400 light years away. It is the first discovered planetary nebula - discovered by Charles Messier in 1764. Basing on the expansion rate which is 31km/s its age is estimated for about 9800 years. In the nebula center there is white dwarf of 55% Solar mass, but the size of only 5% Solar size. 

Picture has been shot with Canon 20D modded camera and GSO 6" F5 newtonian. Exposure time was 35x5 minutes. Setup was driven by HEQ5 mount and guided with QHY5 camera attached to 70/500 refractor.

Next one is Cocoon nebula (IC5146). This one is emission-reflection nebula. The IC5146 symbol corresponds to the star cluster placed in the nebula center. The nebulosity itself is catalogued as Sh2-125 (Sharpless catalog). The complex is about 4000 light years away and can be found in the Cygnus constelllation in one of the richest regions of our Milky Way. There is also dark nebula Barnard 168 (B168) that surrounds Cocoon and extends to the west. It is the dark dust cloud that veils the stars behind.
Setup as before, exposure time was 40x5 minutes.

M33 Triangle galaxy is placed in the Triangulum constellation. This one is much more distant object - about 3 million light years away. It is third in respect of the size galaxy in our Local Group that contains our Milky Way, Andromeda Galaxy, Triangulum Galaxy and around 30 smaller objects. Under perfect dark sky it can be spotted with naked eye. Its diameter is 50 000 light years and contains about 40 billion stars (our Milky Way for comparison caontains about 400 billion stars and Andromeda galaxy about 1000 billion stars).
Setup as above, exposure time 30x5 minutes.

Last target worth to present is NGC891 galaxy placed about 30 million light years away. As you can notice this one is seen directly from the edge. Exposure time 30x5 minutes.

Clear skies!