Observing site: Stormälö, Parainen, Finland
Instrument: N250/1200 mm (10” refractor)
Darkness of the background sky: 2
Weather: Clear sky, warm, calm, noctilucent clouds and northern lights at low altitude in northern sky
Objects observed: NGC 6751, NGC 6755, NGC 6910
Summer 2015 has been mostly extremely rainy, cold and miserable, except for August! In August we had an unique chance to enjoy the most beautiful and warm weather during the days and clear skies (without the Moon!) during the nights as long as for two weeks in a row! During this period of nice weather, I went out observing as much as I could!
During the between 15th and 16th of August I drove again in long time to my dark sky -observing site in Parainen, about 20 km south of Turku. When I arrived at the place, I immediately noticed something unexpected in the northern sky, northern lights! In August! And the sky wasn’t even properly dark yet! I had come to this place for visual deep sky observing, but I had to change the plan because of this unexpected sight! I started to take photos of the aurorae, and later I was able to witness even more unexpected sight – noctilucent clouds appeared in the northern sky at low altitude! Northern lights and noctilucent clouds, together in the sky! I cannot remember that I would have observed these phenomenae together in the sky ever before!
The observing place is a large, open sand pit, and during the days it is being used as a motocross -track. Nearby is also a holiday resort/restaurant, rental cabins and a harbour for small boats. The only source of light pollution is the city of Turku, which makes a light pollution dome in the northern sky. Otherwise the sky is pretty dark. Usually there are now local light pollution sources – except for this time! There was some insect collector with his light trap in the southern edge of the sand pit! Luckily the light beam of his light trap was aimed so that it didin’t cause any trouble to me! Also there was some local noise pollution as there was party group playing loud music and making noises nearby in some of the rental cabins.
Nevertheless, I was also able to do some visual deep sky observing – which was my original reason to come to this place! During the night I observed three objects, which were: NGC 6751, NGC 6755 and NGC 6910.
Here are my notes about these objects:
NGC 6751 is a small planetary nebula in the constellation of Aquila.
Here are my notes of my observation: @80x: small and faint disk, a little bit elongated, long axis in NW-SE -direction. OIII makes the object visible a little bit better.
NGC 6755 is an open cluster in the constellation of Aquila.
Here are my notes of my observation: @80x: faint, rather small, scattered cluster, not concentrated. The stars are in 3-4 clumps, center of the cluster seems to be empty. There is a glow in the background of the starclumps.
NGC 6910 is an open cluster in the constellation of Cygnus.
Here are my notes of my observation: @160x: a small, compact, concentrated cluster. Most of the stars 7-10 magnitudes, relatively poor. The starsof the cluster are in a shape of an arc which is opening to NE. Near Gamma Cygni.
All in all, the night was very good! The sky was already considerably dark (NELM 6.0, SQM 20.8), it was dry and warm, obsrving was very pleasent! And also the aurorae and noctilucent clouds were just added bonus to the night!