This night I had a great observing session. The best since last February first. At least when we talk about deep sky observing

Дата канвертавання24.04.2016
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Hi friends

This night I had a great observing session. The best since last February first. At least when we talk about deep sky observing.

I started by going to the local cinema because it was cloudy. When the movie was over it was clear! Very clear, as I found out. After a quick meal I went outside with my Telementor* and a long list with lots of H400 objects.

It was very windy, but I managed to find a place that offered good protection. It was a bit cold, but not extremely so. There was some haze near the horizon but from about 20 degrees altitude and upwards transparency was very good. The zenith was excellent. Transparency improved slowly during the session. I took great care to protect my night vision once I had achieved it. Naked eye limiting magnitude was around 6. There is very little light pollution here.

I started with M31 just to start with something easy. I was mildly surprised to find that it was just as big and bright as yesterday, even without more than a couple of minutes worth of dark adaption. After exploring M31 and its companions for a while I moved down to M33. Tonight I could "feel" the arms at 21x as well as the central bar.

Realising the opportunity for observing faint galaxies I next tried for NGC 185 and 147, two dwarf galaxies that orbit M31. They are located in Cassiopeia and are quite dim. 185 was not very difficult and could be well seen at 32x. 147 was another story. It was much dimmer and could only be seen with much difficulty at 32x. Another, but unrelated, galaxy, NGC 278 was much easier and could be seen as a small round fuzz next to a couple of stars of comparable magnitude.

I then found NGC 7662, a bright planetary nebula, also in Andromeda. It was bright and star like at 21x, but when you looked at it directly it disappeared! A nearby star of equal magnitude remained visible. Fun! The nebula was bright and easy at 140X, but did not show any details except for a round fuzzy disk. This one takes high power without complain.

The devilishly dim galaxy NGC 7640 has eluded me for years, but I finally grabbed it tonight! It was best seen at 32x, if "seen" is the word here. It was more a feeling of something fuzzy right at the limit of vision among a few very dim stars. In the best moments it was seen to be a bit elongated.

The small open cluster 7686 was easy to find, if a bit unimpressive. Most of the stars are quite faint and a bright star in the middle of the cluster makes them hard to see. 21x provided the best overall view, but 32x brought out individual stars a bit better.

The big bright open cluster NGC 752 could be seen with the naked eye and was very nice in my 8x40 binos. 21x in my Telementor gave a very fine view of the individual stars. Higher power causes you to loose the "open cluster-feeling" as the field is then not large enough to frame it properly.

I took a hasty glimpse at NGC 891 on my way to the galaxy NGC 1023 in Perseus. It was easy to find near M34 at 21x. The view was very nice at 47x. The galaxy is quite elongated and bright enough to be easily visible. Nearby IC 239 was totally invisible.

I then took a dive south and found NGC 772 in Aries. It was very dim, a bit elongated and a bit larger than its symbol in U2000.0 led me to suspect. 32x was best.

A jump back eastward took me into Triangulum and to the galaxy NGC 890 on my way to NGC 925. It was very dim, small and round. But I could hold it for a few seconds at a time in the good moments. NGC 925 was much easier despite having a low surface brightness. It is quite large and a bit elongated. It was well seen at 21x but better at 32x. It is in a nice field.

A couple of degrees north is the small galaxy NGC 949. It was dim but could be held steady at 47x. I think it was a bit elongated.

NGC 1058 2.5 degrees to the east is a member of the same group as NGC 1023 and 891. It is dimmer than the other two and was a small round, dim fuzz. It was quite difficult.

I then took a long jump westward to Cepheus. I wanted to see the dim galaxy NGC 6946 and the nearby open cluster 6939. Both were immediately seen at 21x. They were both quite easily visible in my 8x40 binoculars. The galaxy was a large diffuse glow at 32x, but the cluster started to show hints of resolution. This was even more pronounced at 47x were I could begin to see several stars, perhaps about a dozen. The cluster is very rich but its stars faint.

Since I had the binos up for looking at NGC 6946/6939 I also took a look at the Pleiades. The Merope nebula was quite easy, but the whole cluster was shrouded in nebulosity. Other bright stars showed no glow around them.

The galaxy NGC 6951 about six degrees to the north was another story. It was another very dim fuzz that took some tricks to pull out. But after a few moments I could hold it steady.

Next was the bright reflection nebula NGC 7023. It is centered around a seventh magnitude star and is easily visible at 21x, appearing as if you have fog on the eyepiece. Nearby stars doesn't show this and thus betray the nebula. There should also be a open cluster involved but I saw no hint of it.

I also had to look at NGC 188, a very old open cluster lying just a few degrees from Polaris. It was well seen in my binoculars and displayed beginning resolution in the Telementor. The field is very nice at 21x and 32x.

I also had to try after the UMi dwarf galaxy, but couldn't see a trace of it.

I then turned my attention to Camelopardalis, almost at the zenith. I had to look twice when I discovered that Kembells cascade could be seen naked-eye! The open cluster NGC 1502 was quite nice. The stars are bright and the cluster compact. 21x gave a nice view, with Kembells cascade running through the field.

1.5 degree to the south lies the planetary nebula NGC 1501. It was seen as a very small faint disk at 21x but 47x gave a much nicer view. It appeared as a smaller version of the ring nebula, but without the darker center.

I then went a bit to the north to look for the dim open cluster Berkeley 10. It was seen with considerable difficulty at 32x and 47x as a faint, even glow.

Just a bit to the northeast lies the large faint galaxy IC 342. Imagine my surprise when I easily picked it up in my binoculars! It was readily seen at 21x in the telementor. 32x gave a very nice view and the one at 21x was nearly as good. I saw a hint of central condensation. It was about as large as NGC 6946, perhaps even slightly larger. Several faint stars are located on top and around it.

By now I was cold and hungry, so I decided to go inside and write this report. But before doing that I had to take a look at the great Orion nebulae. It was a superb sight at all powers but especially at 47x.

A very fitting finale for a superb night.

Clear skies!

Thomas Jensen, Denmark

*) Zeiss Telementor, a 63mm f/13.3 achromatic refractor. Equatorially mounted. Here equipped with a Zeiss eyepiece turret and Zeiss 40mm huygenian and 25mm, 18mm and 12.5mm 0.965" KK orthos.

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