April 2, 2013: Jupiter, Panstarrs, more galaxies and a planetary in the north

[michael.h.f.wilkinson]

Yesterday was my second night in a row. I set up the scope early, and while it cooled studied the sky atlas to determine where next to go. At 9:15 I went outside with the 15x70 bins to have a bash at Panstarrs, and was rewarded by a lovely sight of M31 and Panstarrs sharing the 4.4 deg FOV of the bins (as I excitedly posted here yesterday evening). I then turned to Jupiter, as the sky was not quite dark enough to start DSO hunting. Seeing was pretty decent, and the view at 203x was crisp, at 290 in the 7mm XW it was less so, but occasionally the image was suddenly very sharp indeed. No GRS showed.

After another study of the charts, it was dark enough, and I decided to turn my attention northwards (I never left maps 1 and 2 of the Sky Atlas 2000.0 the entire evening). After picking out polaris, I headed south (where else ) in the direction of Camelopardalis, although the first target was in Cepheus. I quickly located NGC 2300, which I had seen before, and studied the region near a nearby star in averted vision. After a while, a faint circle of fuzz became apparent: NGC 2276. This is like a mini M101, a low surface brightness, face-on (barred) spiral. Despite a decent integrated magnitude of 11.3 it is very hard, in part due to the nearby star. Once spotted, it is evident. By contrast NGC 2300 is mag 11.1, but a condensed E-0 so much higher in surface brightness.

Dropping down to Camelopardalis, I looked for NGC 2336. This too was hard, but after a long stare at (or rather next to, averted vision and all that) what I new was the right spot, a large elliptical glow became apparent (at 119x, with the 17mm Nagler). Again, its visual magnitude of 10.3 is deceptive. It is almost like a small version of M33. Nearby NGC 2146 was a similar story, though the appearance was somewhat lumpier. In both cases you really needed to look long for the object, but once spotted, it was unmistakeable.

I revisited NGC 2655 (home of the first supernova I bagged), and it is a very nice little galaxy, compact, elongated, and with a good surface brightness. NGC 2591 proved furtive, and could not be spotted, but NGC 2715 on the other side of NGC 2655 was quite easy in averted vision. I dropped down further south and caught some tantalizing glimpses of NGC 2633/4 but too faint to be sure. IC 520 did not want to play ball either.

I then moved to Draco, and had a go at NGC 4286. No luck at first so I went far north to IC 3568 in Camelopardalis. I almost stumble upon it, as I spotted a not-quite-star with a hint of blue green in the colour at 93x with the 22mm. I first went to 169x with the 12T4 and it was more extended. Sliding in the UHC filter dimmed the surrounding stars, but not the central, slightly extended object. At 203x with the XW10 the effect was greater, and hints of structure seemed to be there. The sharpness of the image was not great, but I realized I was observing objects over the roof of our house, and some thermal currents where wrecking the seeing. Another one of the 100 brightest planetaries bagged.

Back to galaxy hunting, I noticed the finder scope had lost alignment slightly (which might explain the failures around IC 520 and NGC 2633). After realigning it, and realizing I was looking at the wrong pair of stars initially, I found both NGC 4386 and NGC 4291 quite readily. The former was quite easy in averted vision, the latter somewhat harder.

NGC 4589 was nearby, and really surprisingly easy by comparison. It is compact, and has a good surface brightness. A bit further south I located NGC 4750, not hard, but averted vision needed for a good view.

Further south again, I went for NGC 4256, "one that got away" yesterday. This time there was no mistaking the elongated shape of a side-on galaxy. Averted vision was needed.

I swung eastwards towards Thuban and dropped south to NGC 5308, which proved a fairly easy, quite compact, elongated patch of fuzz, and finished with NGC 5322, which is the easiest galaxy of the lot. Bright and large, this was the only Herschel 400 object of the evening. I packed up the scope at about 23:15 and updated the log, accompanied by the usual tot of whisky to celebrate.

This night was really a good demonstration that selecting objects by integrated visual magnitude is insufficient, because this value is the sum total of all the light. Seemingly bright objects may be very hard indeed due to their low surface brightness, whereas compact objects with low integrated visual magnitude might be very easy indeed. I have spotted several mag 13 planetaries with easy, whereas a galaxy of the same visual magnitude might be near impossible.

[Double Kick Drum]

This night was really a good demonstration that selecting objects by integrated visual magnitude is insufficient, because this value is the sum total of all the light. Seemingly bright objects may be very hard indeed due to their low surface brightness, whereas compact objects with low integrated visual magnitude might be very easy indeed. I have spotted several mag 13 planetaries with easy, whereas a galaxy of the same visual magnitude might be near impossible.

Great report.

I totally agree with you regarding visual magnitude. I use a combination of vm and sbr to select targets and as a result, my success rate is still pretty good although will undoubtedly diminish soon as only difficult objects are left on my to do list.

It is always a nice surprise when I glimpse an object close to mag. 11.5 witha higher surface brightness but I accept that most galaxies beyond an sbr value of 14 will be difficult or impossible to see (M33, M74 and M101 as larger exceptions to this).

[michael.h.f.wilkinson]

Thanks DKD. What I also found striking is how important it is to hang in there, and don't give up too easily. NGC 2336 and 2146 were not obvious to the eye, but using averted vision, and taking my time, they suddenly loomed up, almost like a ship emerging from the fog. Once spotted, you wonder why at first you could not see them.

[Special K]

Thanks DKD. What I also found striking is how important it is to hang in there, and don't give up too easily. NGC 2336 and 2146 were not obvious to the eye, but using averted vision, and taking my time, they suddenly loomed up, almost like a ship emerging from the fog. Once spotted, you wonder why at first you could not see them.

Funny how this works but is certainly true. You've hit that persistence thing right on the head! Thanks for the detailed report.