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Observing Session Report - 20th September 2009 (#5)


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Below is the report from my 5th session with the scope. Be warned, it is quite long! However if anyone has the patience to make it to the end do let me know your thoughts. :o

Thanks!

Date: 20th September 2009

Time: 2300 ~ 0030

Site: Colchester Park

Weather: Clear

Limiting Magnitude: 4

Site Notes:

As before, the park offered a good compromise between ideal viewing conditions and distance from my home. The site is considerably better than my back garden (which has several very bright streetlamps over-looking it) but there is still quite a large amount of light pollution, especially when looking South. Again trees obscured several lower parts of the sky, especially to the East.

Observation Summary:

Jupiter was superb tonight; pleasingly each session seems to deliver slightly improved viewing! The giant planet was shorter on moons this time however, with only Ganymede visible to me.

I also viewed another couple of DSOs, although I’m not entirely sure which! I was hunting for M31 but have a feeling I may have missed it and stumbled across M110 instead! I’m a little more confident I found my second target – the Double Cluster in Perseus.

To round this session off I added a number of constellations to my list of viewed objects: Ursa Major, Ursa Minor, Perseus and Andromeda.

Comments:

It had been quite some time since my last session, and I was a little apprehensive about getting the scope set-up, just in case I forgot a vital step! However after about 15 minutes everything was ready and I breathed a sigh of relief. I did notice that I have to adjust my Latitude slightly, which confused me. To get Polaris in view I needed to up the angle from 52 degrees to around 55. I thought afterwards my Declination might not have been exactly 90 degrees – I shall have to pay more attention next time. However, after a shaky start the RDF and I are now best buddies. I am very pleased I spent the extra time aligning it as it’s working wonderfully. I just need to remember it’s a telescope I’m aiming and not an assault rifle…too much Call of Duty lately I think.

I had left the OTA outside for around 90 minutes before setting out, so decided to use it straight away. I was eager to get a good view of Jupiter as I’d spent some time studying maps of its surface and hoped that this knowledge might enable me to pick out some of the surface features. I had good viewing with the 6mm EP for 108x magnification and could make out the North and South Equatorial bands. Unfortunately I couldn’t detect any further detail, and had some difficulty with the aforementioned bands. It was as if someone was turning the brightness of the planet up and down with an enormous remote control! I also noticed that I had to keep my eye at exactly the same distance from the EP to maintain a clear image. I was also hoping to see the shadow Europa cast on the planet as it passed over the surface, however I couldn’t see anything that resembled a darker patch. I also noticed a bizarre effect above the surface of the planet which impaired my viewing slightly. It was almost as if the air was moving, shimmering across my field of view. It reminded me of the heat haze you can see on the road during a particularly hot day.

At this point I handed the scope over to the two family members who had accompanied me as they were very keen to see the King of the Planets! Both were impressed which was satisfying. I tried to combine the 6mm EP with my 2 x Barlow but had the same problem as before – focusing was very difficult and the vibrations caused from touching the focusing wheel really hindered my ability to resolve the image. Doh.

Time to change target and go DSO hunting! Again I didn’t have a map or my laptop, however I did have some drawings I’d done by using Stellarium and hoped they would be enough to locate my desired objects. First up was M31 – the Andromeda Galaxy I’d been hankering after this one for some time; the thought of actually viewing another galaxy had been playing on my mind since I first bought the scope. So I consulted my little drawings and, filled with an odd mix of trepidation and excitement, began star-jumping. My route began at Shedir in Cassiopeia. The constellation’s distinctive shape meant I could locate Shedir straight away. Next I looked across to Mirach in Andromeda by drawing an imaginary straight line from Shedir. I made sure the star I was now looking at was roughly halfway between Almaak and Alpheratz. Satisfied that this was the case, I scanned for the two dimmer stars reaching back from Andromeda towards Cassiopeia. After this I used the fine-adjust cables to scan the area just beyond the second star. After about 30 seconds my Fuzzy sense started to tingle and I used averted vision to confirm I’d found something. I became quite excited, as the location in the sky roughly matched where I’d expected Andromeda to be, and after engaging the motor drive I switched from the 25mm EP to my faithful 6mm. What I then saw was…confusing. I’d expected to be greeted by a view of a galaxy that filled most of the EP, instead the grey fuzzy had barely increased in size at all. I re-focussed, and while I could make out the brighter core I couldn’t resolve any other detail. Sometime later, after consulting Professor Stellarium, I discovered there was another galaxy – M110 – in the vicinity of where I was looking. The size of this galaxy suggested it might have been what I discovered, as it appeared to me about the same size as the Great Cluster in Hercules – around 17 arcminutes. However, either way I guess I did indeed view another galaxy. Excellent!

My next stop was the Double Cluster near Perseus. Locating this object was again a matter of jumping from star to star - something I am growing quite fond of! Starting from Mirphak in Perseus I looked for the 2 stars above it that point towards Cassiopeia. I stopped on the second one, and drew a line to Shedir. I moved along this line for a distance roughly equal to the gap between Mirphak and the first star above it. It sounds very convoluted now I think about it but it seemed like a sensible route at the time! I hoped the Double Cluster would show up more sharply than the Great Cluster in Hercules (which appeared to be a fuzzy grey ball) and I wasn’t disappointed. I could clearly make out some stars that were much brighter than others, but even the dimmer ones were well-resolved. Interestingly, when I changed from the 25mm EP to the 6mm I noticed a massive improvement in contrast – the previous deep blue of the sky was replaced with a much darker hue. I’m unsure as to why, but settled on the better quality of the 6mm EP being the most likely explanation.

At this point it was getting quite cold and clouds had started to obscure large portions of the sky. I therefore decided it was time to pack up, but not before quickly scanning around to imprint the location and structure of several constellations into my brain. I notched up a total of 10 before I started to make up names, which I was quite pleased with!

Overall it was another very enjoyable session. The only downside is that my list of items I feel compelled to by is growing at a worrying rate. It now includes 2 EPs from the William Optics SPL range and I’ve even started scouring the net for a used ToUcam…

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Lovely read and a great report.

In your scope I would say you saw M31 and not M110. M31 would appear small and your description is what you would see with 130mm of aperture. M110 would be alot smaller and pretty hard to spot.

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I love reading reports like this, the thought process rather than just facts :o I'd agree with Mick, if you were looking at M110, you'd definitely have seen M31. So more likely you were looking at M31. M110 is quite a bit fainter.

The heat haze you mention is the atmosphere boiling. Some nights it is worse than others, on good nights is it hardly noticable. When you look at a nearly full moon through a turbulent atmosphere like that it actually looks quite impressive. Makes it more 3D somehow. Well, I find anyway.

Switching from 25mm to 6mm will make the sky look darker because it will let less light through to your eye. That's part of the reason M31 went fainter on you when you switched to 6mm. Smaller apertures like that are better for bright objects like planets. For a lot of the faint fuzzies magnification isn't your friend with a smaller aperture scope.

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Thanks for taking the time to read the report, and for your kind comments! I write these immediately after an observing session and keep them for future reference. My hope is that one day I will be able to re-read them and laugh at my inexperience, but in the meantime I find writing things down helps me to retain the information.

I am delighted that I did find M31 as it was one of my principle targets when I first bought the scope. And now I know how to find it (well, roughly!) I am keen to try again with a different EP. Now that you've explained it, I can see why upping the magnification isn't always the best way to observe objects - especially the fainter ones. Looks like I'll need to use more than just the 6mm EP on my next session!

Thank you also for explaining what the heat haze was. Next time I notice it I will take a look at the moon - hopefully the timing will be right and the moon will be in one of its fuller phases.

What I love about this hobby is that the more I learn the more I realise how little I truly understand. What's more, every time I come to this forum I learn something new!

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I have only just come across your report Adrian, so sorry for the late reply! It's an excellent read - I love long reports, you go in to such detail that really engaged me as I was reading through. I felt as if I was there with you!

Your description of M110 will be a great help to me, I am hoping to spot that one tonight :o Persist with Jupiter, moments of good seeing will come to you with patience and you'll get fleeting glimpses of surface detail. I can't always see the GRS, for instance, but when it does flash through when the boiling subsides, it is a glorious sight to behold.

The double cluster is gorgeous, isn't it :) I have only seen it through binoculars up until now, I am hoping to get the scope on it soon.

Great work, really like your concise and detailed style of reporting :D

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Great report, love all the detail and that you were able to share the viewing with others.

I would suggest you try M52 just up from Cassiopea. It is relatively bright, getting high up now, relatively easy to find with binocs first and then line up the scope, its pretty etc etc....

Hoping for clear skies!

Mark

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Hi Amanda, thanks for the comments - I'm happy that the reports are enjoyable to read; I was worried they might be a little verbose but it seems most people here either like them or are too polite to say otherwise! :) I actually posted a couple of earlier ones in the general observing discussion forum (I didn't realise what this one was for at that point!) so if you have some free time you may enjoy those too.

I think, from what Mick and Julian said, the object I saw was in fact M31 and not M110. My confusion came from thinking what I could see was all there was to see of M31 (hence its small apparent size), when in fact the dim shape I was viewing was actually the brightest part of the galaxy. As such I'm afraid my little star-hopping adventure might not be of much help to you...hopefully I'm wrong, though!

Yes, the double cluster was lovely. I am wondering now if 6mm was too much magnification (108x I believe), hopefully I didn't accidentally cut out some of the outer stars in my haste to view this object clearly! Now that I know where the cluster is I am going to try all EP combinations and see which gives the best view.

Hi Mark, thanks for the suggestion! I wasn't sure what M52 was, but after a quick Stellarium consultation I can see why you recommended it! It is now on my list of objects to view and I will enjoy hunting for it during my next session. :o

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