Category: Deepsky log

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Polaris
In the low light of dusk we started of with a one of my favourite double stars, Polaris. What struck me was how easy it was "to see" the double in both telescopes. The white B component was very easy to see, next to the yellowish A component. The separation is a generous 18", but I always have to take a good look to see the B-component. Later that night we revisited Polaris and it was a very different story. The 2nd magnitude A component almost completely outshone its magnitude 8.2 companion. Of course it was a lot darker later in the evening, during our second visit of Polaris, so the difference in brightness was much more apparent than earlier on.

16 Cygni and the blinking planetary (Caldwell 15)
The next stop was another nice double, 16 Cygni, which had a companion in the same field of view, NGC 6826 (The Blinking Planetary). 16 Cygni consists of two yellow-golden suns of almost equal magnitude, separated about 40" from each other. About 30' to the northeast of 16 Cygni I spotted the Blinking Planetary. In the 21mm Denkmeier with a field of view of 51' it was easy to get this bright planetary nebula into the same field of view with 16 Cygni. A nice couple of objects to look at. It is a very strange experience, watching the Blinking Planetary. If you look straight at the central star (which is visible even at the lowest magnification of 76x) the nebula seems to disappear. However, if you look a bit to the left of the Blinking Planetary, using averted vision, it pops into view.

I tried several magnifications (76, 133, 229, 320) but the blinking effect disappeared at 320x This was for me the optimum magnification to look at the nebula. It was perfectly round and I could detect no real areas of uneven brightness, and there is no well-defined sharp edge to the nebula. It showed only a hint of bluish-green colour tonight. It was very difficult to really "see" the colour. The OIII filter killed all the stars in the field, so I switched to the UHC narrowband filter. This enhanced the contrast a bit but I still like the view without filter most.

T Lyrae (Carbon Star)
Again a star that surprised us. Last year we have been looking for it with the 10-inch TAL but only after increasing the magnification to 200+ we could find it. It was very dark red and almost invisible at lower magnifications. Last Saturday I pointed the 12-inch dob at the location where I should see T Lyrae, and there it was. Not dark red and invisible but very bright and intensive orange. This is the first variable star that I have ever observed near its minimum and near its maximum, and I must admit, it's a great experience. I never imagined that two magnitudes could make such a huge difference in visibility.


Image from Skytools by CapellaSoft


Phil Harrington's STAR 22, the mini-coat hanger
Next on the list were three objects from Phil Harrington's STAR list (Small Telescope Asterism Roster). The first to visit was the Mini-Coat hanger in Ursa Minor. It looks like a smaller version of Collinder 399 in Vulpecula, the (big) Coat hanger. It is made up of 11 stars and the diameter is about 30'.

Phil Harrington's STAR 23, the backward S and STAR 24, a conspicuous ring
These two asterisms can be found in Hercules. I just had a quick look, but all three STAR's from Harrington's list will be revisited for a closer examination and a sketch. At this point we went indoors for a short break and some refreshments.

Double Cluster (Caldwell 14)
After the break I turned my telescope towards the Double Cluster in Perseus, NGC 869 and NGC 884. In the Dobson I immediately noticed a difference with my 8-inch TAL. The colour in some stars was much more obvious in the 300mm Dob. At lowest magnification, 76x, I noticed three bright yellow stars among all the blue/blue-white stars of NGC 884. When checking with my observing bible, "The Night Sky Observers Guide", I got confirmation of my observation. Three red super giants can be found in NGC 884.

The screaming owl
This is not some obscure asterism, but something that scared us like hell. Around 1.30 on Sunday morning a large bird, with a wingspan of two to three feet, flew over us screaming like the devil himself was on his heels (or tail actually). After little investigation on the Internet it proved to be a Barn Owl. Wow, what a sound! Turn up the volume real loud and .........Click on this link to get an idea......but be warned, this is not for the faint-hearted!

And here is an image of this wonderful bird.


Click to enlarge


NGC 7510 and Markarian 50
After we managed to get our heartbeat down to a normal rate again, we moved to our next stop, two open clusters on Perseus-Cassiopeia Border, NGC 7510 and Markarian 50. NGC 7510 is a lovely object, even at low power. It looks like a kind of arrowhead at 76x. I liked the cluster best with the 5mm Pentax, magnification 320x, FOV 13'. The cluster is only 4' in diameter so there's plenty of room left in the field of view. I counted about 25 brighter and weaker stars that where arranged in a kind of small circle with three legs dangling from the circle. In fact it looked like an octopus! I could detect no background nebulosity and no coloured stars. Next stop was Markarian 50, but this cluster proved to be almost invisible tonight, so we will try it on a night with better transparency and sky-darkness.

M52, Czernik 43, and NGC 7635 (Bubble Nebula, Caldwell 11)
From the invisible Markarian 50, it was only a small step to a very interesting trio, just across the border to Cassiopeia. You can get two open clusters, M52 and Czernik 43, and an emission nebula, NGC 7635, into one field of view. M52 is a very irregular cluster without a real shape, while Czernik 43 looks much more organized, a kind of large triangular shape with 4 bright stars on a row on one side of the cluster. The Bubble nebula was only visible with the highest magnification and averted vision. With direct vision it stayed invisible. This is an object which we have to revisit under better conditions (no Moon, better transparency and darker skies).

At 03:00 we ended our observing session. We saw quit a few wonderful objects tonight, but for me the one thing I will remember is that impressive large bird, breaking the silence with its very harsh call. It was very special to see him soaring through the night sky, only lit by the light of the Moon. It was the first time ever I saw a barn owl and I hope I will see one again somewhere in the future.
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The equipment I used with the 300mm f 5.3 Dob:

Eyepieces
1. 32mm Plossl (50x, afov 50 deg, tfov 60', eyerelief 22mm, exit pupil 6, and Dioptrx 1.0)
2. 12mm Nagler Type 4 (133x, afov 82 deg, tfov 37', eyerelief 17mm, exit pupil 2,25)
3. 7 mm Pentax XW (229x, afov 70 deg, tfov 18', eyerelief 20mm, exit pupil 1,3)
4. 5 mm Vixen Lanthanum (320x, afov 50 deg, tfov 9.4', eyerelief 20mm, exit pupil 0,9)

Filters
Lumicon UHC and OIII

Overall impressions
After the first 5 to 10 observing sessions in my light-polluted suburban backyard (limiting magnitude 4.5 to 5.3), there is one thing that is very clear to me: aperture really can make the difference. When I was observing with Jo, a fellow observer who also got the Orion Optics UK 300mm very recently, we both agreed that the views with the 300mm on a less than average night are better than with our 200mm telescopes on the best night ever. Not only the amount of detail you see in many deepsky objects is simply amazing, the bigger scopes also make it possible to observe a lot of objects that were more or less invisible in the 8-inch telescopes we've looked through. I have been told many times that buying a telescope with a larger aperture is of little or no use if you live in the suburbs. Well, maybe that is through for one class of objects, the fainter galaxies, but for all the other objects I have been looking at during the last few months (including the big bright galaxies) the story is very different. They all look better, brighter, more detailed and some of them even show some colour!

I also am convinced that for visual observing, this is the system for me. It is very quick to set up, and following objects by hand is very easy with this scope. If you have the balance right, you can follow objects without a problem, even with magnifications up to 457x (I've tested this with a 3.5mm Pentax XW eyepiece I borrowed from a fellow observer). Also switching eyepieces at higher magnifications isn't a big Issue, if your eyepieces have a large apparent field of view (68 to 82 degrees). With my Vixen LV eyepieces, which have an apparent FOV of 50 or even 42 degrees, the objects rush out of view at higher magnifications. All in all I can say that this will definitely be my most used telescope for deepsky observing.

Open clusters
I have observed a large number of open clusters, M35 and NGC 2158, M36, M37, M38, M48, M67, the double cluster, NGC 7789, NGC 2301, NGC 457, M103, and many more. They all looked brighter, showed more fainter stars and simply looked beautiful, a real pleasure to just look at and enjoy the views! I also tested the Dob by hopping along 20 not so bright clusters in Cassiopeia, which I had observed with the 8-inch in the last few years. I remember that with the 8-inch most of them where very difficult to detect from my magnitude 5 backyard, but with the 300mm dob they all were visible on first sight. Other fainter / smaller clusters like NGC 1907 (near M38) and NGC 2158 (near M35) where resolved into many pinpoint stars. All the very small or faint clusters, which my TAL 200K simply did not show, were no problem for this telescope. The eyepiece I liked most for the clusters where two I borrowed from fellow observers, the 22mm and the 24mm Panoptic from Televue. I probably will replace the 32mm Plossl by the 22mm Panoptic (about the same field of view, but much higher magnification and excellent exit-pupil of 4mm).

Planetary nebulae
I was in for a big surprise! I only looked at a few planetary nebulae but I will never forget my first look at the Blue Snowball (NGC 7662). This planetary is really blue! I never saw any colour in my 8-inch telescope when observing deepsky objects, but in the 300mm, bang! The colour was best with the 24mm Panoptic I borrowed, but in the 12mm Nagler and the 7mm Pentax the colour was also very easy to see. Last Sunday night I observed NGC 6210 in Hercules. This planetary was also strikingly blue in my 7mm Pentax and 12mm Nagler. I also tried the UHC and OIII filters. NGC 6210 became brighter, but the colour disappeared. I liked the view without the filters best. Then I visited another planetary last night, M 97 in Ursa Major. I was surprised that I could see it at all from my suburban backyard! I had never seen it before with the 8-inch, except one time when I was in Austria at 1800 meters I did see it with the TAL 200K. And what can I say, well with the UHC filter M 97 was very easy to see, a very big planetary, better than I ever seen it before, even better than at the star-party in Austria, which is at a higher altitude and has a much better seeing transparency. I tried to detect some details (the eyes of the owl), but I could not see them. However, I am convinced that I will see them from a dark sky-observing site. So what can I say about the planetary nebulae I've seen with this telescope? They all where brighter, much easier to see, and some of them even showed some colour.

Emission nebula
There's only one emission nebula I observed, and that was M42( and M43 of course). What a beauty at all magnifications, and what a detail! I looked at M42 at least on 5 different nights. In the Trapezium the E component was always visible, and the F component could be detected on 4 out of 5 nights. But the most stunning area was the bright central part of the Orion nebula. The details where amazing, even without a filter. Now I finally know what the Frons, the Occiput, the Pons Schroeteri and Sinus Gentilii are (I will publish a separate article on this!). There are lots of other structures left to detect, but on the first few nights I simply sat and took in the wonderful views. This has definitely become my favourite winter object. My 8-inch TAL cannot compete with the 300mm Dob on M42 / M43, I am really looking forward to the next winter, when I hope to see the Orion Nebula from a dark sky site.

Globular clusters
Last Sunday night I observed three globular clusters, M13, M3 and M92. I can be very short: they where all resolved right to the core. These objects are simply 10 times better than in the 8-inch. At 133x and 229x M13 looked liked a giant propeller, with chains of stars running from the core across the cluster into the dark sky, creating different streams of stars with dark lanes between them. I want to take up deepsky sketching again, but I think that I skip M13 ☺
The amount of stars is just overwhelming. M3 and M92 where also beautiful to see and I am looking forward to observe a few more globular clusters this year. They really look much better in the 300mm. The 200mm Tal only could resolve M13, M3 and M15 right into the core on the nights with a good seeing, but most of the time the larger parts of the globular clusters stayed hazy. Not with this telescope!

Galaxies
And now for the galaxies. I only had a look on a few of the bigger galaxies. They also looked a lot better than through the 8-inch. M81 and M82 in Ursa Major were the first two galaxies I had a look at. In my 8-inch M81 looked like a small circle and M82 like a small elongated patch of light. In the 300mm M81 looks really huge, a big more or less round (a little oval) galaxy. M82 looks like a big cigar. It shows a lot of detail at 133x and at 229x. The elongated bar of light is broken in two or three places by dark lanes and I could detect two "brighter" areas. M65 and M66 were very easy, even on a night with a mediocre seeing and transparency. Last Sunday night I had a look at M51 and it's companion NGC 5195. Now through my 8-inch I only saw two more or less points of light, with a little haze around it and sometimes, from my backyard, I could not see them at all. Last Saturday, when the transparency was not so good (a lot of high clouds) I did see a little more than usual, but it still was a bit disappointing. Sunday night however, the sky was a lot clearer and there it was, M51 looked like a really big round smudge of light with a very bright core and some areas of uneven brightness detectable in its disk like structure. NGC 5195 was a lot smaller but also had a very bright core. I am sure that from a dark-sky site, M51 will reveal some of its spiral structure.

Well, that’s all for now. I hope we will have a lot of clear skies in the next few months, and I will keep you updated! If you have any questions on the scope, or want to react on this article, please feel free to do so.


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