Observing Reports from Rosliston Astronomy Group

[athornett]

Observing Log 23/8/2014 @ 22:00 - 24/8/2014 @ 01:30 Swadlincote Nick (Cotterlass45 from Star-gazers lounge) and Andrew.

Nick's House

C6R Celestron 6 inch refractor 1200mm focal length on HEQ5 Pro mount with GOTO (Heq 5 pro with Synscan hand controller).

I also bought my 222mm David Lukehurst scope and 20x80 binoculars but both stayed in the car as Nick gave me a fantastic tour of the night sky.

Where numbers only given for an object, this refers to NGC objects.

Nick observes from a garden with a large visible proportion of sky. The neighbours' gardens are quite dark, although he does need to use a screen in one direction to obscure some upstairs lights from one neighbour's house.

My first impression of Swadlincote was of surprise that the location was closer to Burton than I thought from Nick's previous reports. He has observed so many wonderful things that I thought he was located deep in the country! The Milky Way was visible, but only just, although Nick profusely expressed his appreciation of the sight. It did not match up to the incredible views of a bright milky band I had seen a few weeks ago in Devon on holiday. However the sky was not yet as dark as it would be later in the evening. Lovely clear night, I suspect because of cold front predicted with lots of rain for the Bank holiday Monday.

First object we looked at was Comet Jacques. A fuzzy quite large object at 80x magnification with quite bright core, still, visible in 9x50 finder scope. No visible tail. To my embarrassment this is the first time I have seen this comet although several members if RAG have submitted photos and descriptions to the group's mailing list. The comet was visible in Cassiopeia. To find it, we located the two stars in the middle of Cassiopeia's W asterism, Shedar and Navi, and continued the line between them north about same distance again as the distance between them. However this is a fast moving object and won't be there tomorrow, and in fact had moved even in the hour or so before we looked at this comet again later in the evening.....but more of that later in this report.....

A recurring theme in tonight's session was Nick's desire to entice me over to the dark side....that is to show me multiple star systems so that I would become enthral led by their beauty and develop a passionate interest in observing them! Although he did not turn me into an avid double star observer, he did achieve quite a lot in this endeavour, enabling me to appreciate the beauty and splendour of these systems. He started by showing me the star Psi Cassiopeia, a triple star. At 200x magnification, there was a bright superior star in field of view and faint one at bottom. When I stared at the top bright star, it eventually split into two, a dimmer blue star and brighter white star. Took a few seconds to get it though!

The next double star we saw was an unclassified double star from a book Nick has, called "1800 new double stars for amateur observers". I don't think it would have been easy to see without the Synscan hand controller taking us there, though.

Next we looked at an open cluster in Cassiopeia, 663, using a Meade 4000 zoom eyepiece at 100x. This filled the field of view, and the central 15% had a fuzzy, almost nebulous, appearance which I had not noticed when I observed it in the past.

"Blue flash" planetary nebula in Delphinius, NGC6905, described by Nick as a weird planetary. To me it looked quite bright through this scope with the zoom eyepiece. At low power, it appeared to explode as I looked away and averted vision kicked in, and this alternating shrinking and exploding was quite pronounced. Little extra detail at high power. This blinking effect on planetary nebulae was quite pronounced tonight on the several we observed, and was in significant contrast to the non-blinking nature of adjacent stars which, in many cases, did not look any brighter than the nebulae. I can't understand why this should occur given the. Apparent similar magnitude (at least to me) - perhaps someone can explain it for me?

Veil Nebula 6992 and 6995 - swinging between these two nebulous NGC areas using the Synscan hand controller  to control the slew with a Skywatcher UHC filter in place - this allowed me to follow the curve around and clearly demonstrated that 6992 and 6995 are part if the same C-shaped curved object. The Synscan really helps with this type of exploration. I also noted whilst writing these notes during this observation that viewing the iPad even with thick red cellophane on it affected my night vision enough to dramatically reduce my ability to observe this object.

Next we viewed the "Hole Cluster" in Cygnus,  6811. This open cluster has a large hole in it - actually I could see two holes alongside each other! Large circular streamers of stars connected to each other.

147 is apparently the brightest galaxy in Cygnus, magnitude 9.1. We tried to look at this with 8-21mm zoom. Our first failure. Sky too bright we decided. Even changing eyepieces did not help. The advantage of the Synscan is that we knew for certain that it was there in front of us in the field of view of the eyepiece.....it was just that we could not see it. You will see from our observing notes below that this seems surprising, given the fact that we later observed dimmer objects than this successfully. It might be due to lower surface brightness although integrated magnitude was not too bad for the galaxy, or the dimmer objects might have been observed after the sky got darker.

1023 in Perseus is another bright galaxy with high surface brightness. Unlike 147 this gave us a good view, streak with particularly bright core just off two stars. I think the bright core makes a lot of difference, because once I saw that I then could could concentrate upon observing the area of sky immediately to either side of the core until I could start seeing the fainter outlying regions of the galaxy and, in this case, make out the linear shape.

Caroline's Rose, 7789. Open cluster. My impression was that, compared to the view through my 16 inch Dobsonian if this same object, that tonight's view was far less bright BUT that the stars were far better resolved in the refractor tonight than when I observed Caroline's Rose in my 16 inch Dobsonian reflector.

Worth noting that the sky was very still, although not particularly dark, at this point.

884 and 869, the Double Cluster in Perseus. Through a cheap 32mm Plossl. Actually really nice view. Both in same field. Achieved the bright jewels on black velvet view due to high contrast that I love so well in the 16 inch Dob. Well done, Nick!

7331 galaxy in Perseus. Streak from 1pm to 7pm in field of view, also with bright core.

M27 without filter at x60. Very big, very bright, clear Dumbell shape, plus round surrounding nebulosity. Surprisingly bright as only 6 inch scope when I am used to much dimmer view in larger Dobs. Perhaps this is due to differences in contrast? Or perhaps due to the sky? Or just quality of the scopes? With UHC filter at x80, the contrast increased, could see brighter side but otherwise I did not feel added great deal to previous view. That was quite a surprise to me.

Tea break....now time was 23:00......Milky Way much more obvious with Cygnus Rift evident as sky getting darker. I notice that Nick does not have the red glow around his horizon we have to put up with in Lichfield, suggesting light pollution levels lot lower, in spite of his location of edge of Burton-onTrent. Sky very clear.

Open cluster in Cepheus 6939, one of ones with star cloud in and around it from Milky Way. Not particularly impressive in this scope in my view although Nick waxed lyrical. It looked like a cloud of stars to right of bright star.

Only problem with Nick's scope is tendency to keep tripping over the tripod legs. Do not get that with Dobs!

Running Man open cluster 1535.  Main stars visible but too bright in sky to see the running man properly. Nick assures me it is lot better when sky darker. I can believe it, especially in view of my recent Devon experiences.

7217 is another side-on galaxy in Perseus that looked like a faint slash and bright central core when I looked at it.

Next we looked at three Struve multiple stars in Cepheus: Struve 2815, 2816, and 2817, two doubles and triple. Involved Nick entering galactic co-ordinates into Synscan. All in same field of view. The triple showed two blue stars and a brighter central white star. Both doubles had bluer star and whiter star.

Next we slewed to Delta Cepheii, a pulsating yellow variable and blue companion. Nick was definitely trying hard to get me to be enthusiastic about double stars! These stars at 60x showed contrasting colours - the contrast was very obvious in this scope. Very beautiful. What surprises me is that I had got it into my head that double star observing was all about splitting close pairs but often (as here) stars turn out to be quite a distance apart in the field of view, at least at the magnifications Nick was using tonight. These two were 40 arc-seconds apart and that distanced seemed about average for ones Nick showed me tonight. Nick's preferred book on which double stars to observe is by Sissy Hass, the one I mentioned before.

I mentioned above that Nick was using the Synscan GOTO hand controller tonight. His scope is on a HEQ Pro mount. Great for GOTO but I am not sure I would want to try star hopping with this mount. The axes don't really allow for easy manual star hopping. Being orientated to RA and dec does not make it easy, although perhaps Nick is able to do it. Therefore, when I buy a refractor, I would like to have both alt-az and EQ mount options available.

Back to a Comet Jacques for another view now sky darker using Baader Hyperion eyepiece at 58x. The coma looks larger now around the "nucleus" although of course the bright centre we can see is actually part of the coma as we can't actually see the nucleus itself. Tried higher magnification with 8.8mm Meade 4000 ultra-wide, so magnification = 1200/8.8=ca. 136x. Contrast a lot higher but comet very dim. At 120x the edges of the coma of the comet was easy to make out. I could not make out a tail.

M31 Andomeda a Galaxy bright core visible but extensions of peripheral regions to either side not visible in way they are in large Dobs.

The Ring Nebula - very bright with darker centre and crenulation on ring itself. Great view. Some of the views tonight in this scope are really excellent and beat the Dobs hands down and this is one of them. The Double Cluster another.

6934 globular cluster in a Delphinius at 120x. Bright fuzzy - good view but lack of resolved stars means this could easily be confused for planetary nebula as quite small. Refractors appear to do well on planetary nebulae and particularly on relatively bright small objects. This refractor resolves detail well although very bright stars show some slight elongation in one direction, but so far not stopped us splitting the double stars we have looked at here tonight.

Struve 2738 in Delphinus. Blue star to left with white star close and another white further off.

Eta Lyrae, Aladpar. Bright star with faint companion. The Synscan got everything we looked for tonight in field of view using its GOTO usually with objects searched for close to centre of field of view even moving slewing across sky from one side like the other.

Double double in Lyra. Epsilon Lyrae. With Meade 5.5mm 5000 series eyepiece cleanly split both pairs. Nick could see them split with 8.8mm eyepiece but I could not and needed the higher magnification of the 5.5mm. The two sets of double stars are at right angle orientation to each other. This is first time I have ever seen them clearly split like this!

Struve 2470 and 2474, this is the other double double in Lyra and tonight I noted it had a parallel orientation of the two sets double stars unlike the right angle of the first double double. The different orientations between the two sets of double doubles in Lyra is really quite arresting. This is the first time I have seen this latter double double set, although I read about it in one of the magazines.

Another double double in Delphinius, Gamma Delphinius, which Nick said "we should pop at 60x". Right angle orientation between pairs again, one pair significantly brighter than the other.

Now it was 23:49 and the sky was beginning to look somewhat hazy, I suspect from moisture. Milky Way had faded somewhat compared to earlier although we could still make it out in Perseus.

Next was the Garnet Star in Cepheus. This is famously red. However it looked so bright it was virtually white with a red tinge. However, if Nick stepped on paving slabs that the scope was placed upon, then the scope shook and at that point when star was moving I noted it looked much more red in colour, suggesting the white colour was simply due to the star being too bright in the scope.

Omicron Cepheus is an orange giant star with blue companion, 3.2 arc-seconds apart. So Nick increased magnification to 216x to split these. This is something I would not be able to do with one of my Dobs! Needs a refractor on good mount. 

Galaxies in Ursa Major were next on our agenda. M101 very faint small part of core only. M81 and M82 bright great view. M51 - I couldn't see it but bright and just above house in that direction.

The open cluster M34 - Nick sees a scorpion or pair of underpants. I see a scarecrow, a bit like the Owl Cluster, confirmed by immediately slewing to the Owl.

I decided to compare some open clusters in Cygnus. The GOTO made this really easy. 6811 in Cygnus is an open cluster - I saw a loose collection with cross-shaped dust lanes, 15% field of view in Hyperion 21mm eyepiece. Comparing this to 6866 which is much looser with some prominent bright stars. 6910 - much more compact very bright stars. 6819 - faint and small. Difficult to make out against background star clouds of Milky Way. 6791 - very faint against background stars not surprising as magnitude 9.5.

From the Astronomical League's observing guide for open clusters, the following is mentioned regarding classification of open clusters:

"One of the earliest classification systems was developed by Harlow Shapley in 1930; it had seven components.

a. Field Irregularities: This class deals with irregular star counts and associations. They differed than the normal distribution of stars, being more closely concentrated yet not enough to be studied.

b. Star Associations:This category contains clusters thathavedistantlyspacedstars sharing the same motion. The Ursa Major group is a member of this class.

c. Very Loose and Irregular Clusters: These are very large and scattered clusters. Examples of this class include the Pleiades and Hyades clusters, and the alpha Persei group.

d. LooseClusters:Theseclustershaveverysmallamountsofstarsandappear loose. Shapley gave M21 and M34 as examples of this type.

e. Intermediate Rich and Concentrated: These clusters are more compact and concentrated; M38 is in this class.

f. Fairly Rich and Concentrated: This group is a compact as the e group, yet with more stars; M37 falls in this group.

g. Considerably Rich and Concentrated: This group is similarly compact as group f, yet contains more stars; the Jewel Box (NGC 4755) is in this class.

Shapley immediately found that his classification system was not complete because it was dependent on stellar density and distance of the group. With this knowledge he further divided the group into the color of the stars in the cluster. The Pleiades type, where the stars where mainly Main Sequence, and the Hyades type, where the stars were older yellow and red spectra. Even with the later addition, the Shapley classification system has fallen out of favor because of the astrophysical limitations; it is dependent on density and concentration.

Robert J. Trumpler devised the classification system that is the most widely used and accepted classification of open clusters because it independently assesses the nature of the cluster. Trumpler identified three features in an open cluster:

Degree of Concentration:

I. Detached clusters with strong central concentration.

II. Detached clusters with little central concentration.

III. Detached cluster with no noticeable concentration.

IV. Clusters not well detached, but has a strong field concentration.

 Range of Brightness:

1. Most of the cluster stars are nearly the same apparent brightness.

2. A medium range of brightness between the stars in the cluster.

3. Cluster is composed of bright and faint stars.

Number of Stars in Cluster (p. m. r.):

P. Poor clusters with less than 50 (fifty) stars.

M. Medium rich cluster with 50-100 stars.

R. Rich clusters with over 100 stars.

Some open clusters may be in, or are surrounded by nebulosity:

n. Trumpler denoted open clusters with any type of nebulosity (including light and dark nebula) with an “n” at the end of the classification.

For example, the official classification for 3293 is I 3 r n because it is imbedded in a nebula. If you find that any of the selected clusters in this program are in or around nebula, denote that in your classification of the cluster."

We explored some planetary nebulae: The "Blue oyster" 1501 at the end of Kendle's cascade, one Cassiopeia length to end of Cassiopeia. Faint circular nebula without detail, did not require averted vision. Seemed a good opportunity to compare this to some other planetary nebulae. Next was "Blue Snowball". Fuzzy star, slightly blue/green in colour, kept disappearing as looked at it, then re-appeared when looked to aside, very prominent effect that was not seen with adjacent stars - the contrast was weird and evident even though the nebula was bright. The "Cat's Eye Nebula" in Draco 6543 blue/white averted vision effect evident but less prominent. Nick increased magnification to 216x. The "Cat's Eye" is now about 10x the size of adjacent star, still averted effect evident still looks bright, little detail though. "Lime Nebula" IC3568 in Camelopardis. It took 216x to see this 11.6 magnitude object. Looks like faint star at lower mags and even at this magnification to me, although at 216x Nick thought it looked non-stellar. Next we went to see the bi-lobed 6765 in Lyra. Magnitude 12.9, blue and faint, very faint definitely non stellar smudge at 216x which disappeared completely on looking at it and appeared on looking to side. This blinking effect of planetary nebulae seems very common from tonight's experiences! Next was 6884 in Cygnus. At 50x, few stars that could be it but nothing definite to me. With 8.8mm eyepiece, still not obvious to me which was the planetary nebula.

Couple more failures: "Running Man" still little to see. "Pacman Nebula" 281 - sky too light little to see.

Then a successful observation: "Jolly Roger", 1502. Compact open cluster with two bright central stars and some extensions which look bit like skull and cross-bones. At higher magnification looks more like number 7 to me.

I had to reluctantly leave Nick at 01:30.

I would like to thank Nick for a fantastic evening and for showing me many objects I had not seen before and others with the best view I have ever seen. Of course, Nick and I had a great chat about the Peak Star Party and many things astronomical. I am very impressed by the quality of his skies and his scope and mount perform admirably. I would love to join him again in Swadlincote.

Andy

[cotterless45]

You are welcome. It was a fantastic night to share the views.

Thanks for posting,

Nick.

[Bodkin]

That was an excellent report.  Thank you.

[FenlandPaul]

What a fantastic sounding evening. Thanks for posting a great write-up and massive hats off to to Nick for an exemplary night sky tour.

Sent from my iPad using Tapatalk

[Stu]

Fantastic report, will re visit and read fully later. Sounds like a great night!

I knew Nick's skies were better than he says ;-)