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The diminutive dolphin


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Recently some of the best nights have been on Sundays, which is a bit naughty before a week at work but also a great way to unwind and clear the mind and it’s on that basis that I justified putting the scope out late this afternoon ready for a session this evening.  After a great session last Sunday on some doubles in Delphinus, I’d  earmarked tonight for a deep sky tour of the dolphin followed by some indulgent galaxy hunting in Pegasus.  Interstellarum was my companion.

As the last signs of twilight dipped to the west, my first target was NGC 6950.  This was a loose and uneventful open cluster comprising 20-30 resolvable stars that was only slightly more concentrated than the background.  There was a hint of unresolved fog from time to time.  The view was best at low power, but hardly spectacular even then.

NGC 6934, the globular cluster, was a fairly easy star hop from Epsilon Delphinii; I’m finding the Telrad / RACI combination excellent for hopping about quickly.  At low power in the 32mm TV Plossl, the cluster was a small, obviously fuzzy blob.  Switching to the 20mm didn’t add anything exciting.  But at x214 in the 7mm Nagler it took on a mottled appearance, brighter towards the core.  With averted vision individual stars seemed to pop in and out of view.  A slightly orange star sits just to the west, leading the globular across the field.

NGC 7006 (also Caldwell 42), another globular, was a dim, hazy and compact patch at low power.  At x214 it was more obviously a round, globular cluster but no stars were resolved and it was still quite dim.  The slightest hint of mottling appeared with averted vission, but mostly it was amorphous and brighter towards the centre.  Not an impressive globular, but interesting to contemplate its importance in the use of its RR Lyrae stars for determining galactic distances.

Next I tried to locate the galaxy NGC 7025, which forms the base of Sue French’s “Toadstool” asterism.  Whilst I could see a loose collection of brightish stars, I couldn’t detect the galaxy nor work out how the pattern made a mushroom-shape. 

Over to NGC 6905, the Blue Flash Nebula.  This was quite a challenge to find, following a confusing star hop from Sagitta.  In the end, I used the Telrad to plonk the scope in approximately the right place and then identified the field stars on the map, before homing in.  At low power, it was a fuzz that didn’t quite appear round, with a brightish star fixing its northernmost edge.  At high power the disc became much rounder and appeared to be less bright on its north western side.  The disc was generally uniform (except for the NW dimness) and very round, with no central star visible.  At high power it sat on the western sie of a triangle of stars that neatly encases it.

Another planetary next, with NGC 6891 which was a straightforward star hop from Epsilon Delphinii.  It was almost stellar at low power and I would have overlooked it has I not pinpointed its position with the hop.  At high power it appeared as a bright, out-of-focus star, but no real detail was visible even at x428.

I tried a few galaxies next, including the pairing of NGC 6930 and 6928 as well as NGC 6956.  None of these were visible, and I began to notice that the sky wasn’t as transparent as it had been earlier on; the dew-sodden air just didn’t want to give up galaxies!  So that rather scuppered my plans in Pegasus.

There was one object, however, that the flying horse was not going to keep from me: the wonderful globular M15.  A hop from Epsilon Pegasi, it appeared as a fuzzy star in the finder.  At low power it was clearly a reasonably large globular with a very compact, almost stellar core.  Its surface brightnessdrops off quickly but the cluster remains discernible some way out.  At high power, in the 7mm Nagler, it was transformed into a really well resolved cluster.  The stellar core that has been seen at low power softened to give an unresolved central quarter rather than point.  With averted vision it was possible to see an almost spiral structure, with the main arm spinning off from the north and folding round to the east, and another tendril extending from the south east side.  As it glides across the field it holds resolution well, even with direct vision, and it appears criss-crossed with a number of dark lanes.

As the humidity started to suck the light from the sky, I just sat back and watched the Pleiades rise up in the north east, as a couple of sporadic meteors burned up to the south.  Perseus and Auriga looked splendid to the north, and to the north west the Plough and Ursa Major looked enormous compared to the diminutive dolphin that had shared so many of its beautiful treasures this evening.

Thanks for reading!

Paul

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M15 must be great under darker skies! My first glob to capture under Athen's light polluted skies!

Great report with interesting targets. Smaller and overlooked constellations often hide some deep sky treasures or even great doubles!

Cheers from Greece

Tzitzis

Edited by Tzitzis
typo
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Golly what a great report on a fairly small area of sky, I never understood there was so much there, I was looking around that area the night before last and only latched on to a quarter of your targets, I do find some of the NGC objects a bit of a let down even with a big scope.

Alan

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Lovely detailed report of some very nice objects. I keep forgetting to use my copy of Interstelarum, especially for planning, its too easy to open the ipad...I shall rectify this tonight.

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Terrific stuff. Some interesting sounding targets off the beaten path. Glad you got some viewing in before the contrast dropped. It was similar here - seemed odd as the scope slowly but steadily started pulling less from the sky, while to the naked eye it didn't seem all that bad.

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Have affections for the little Dolphin (and Sagitta) re. Skool Hollidays  in Wales.
First fainter constellations I became familiar with...  and also contain interesting
objects I still "discover" (as above) to this day! :)

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Super report Paul :icon_biggrin:

I've got my dob out this evening so I'm going to use your report as a guide and explore this area of sky. Thanks for highlighting it !

 

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25 minutes ago, John said:

Super report Paul :icon_biggrin:

I've got my dob out this evening so I'm going to use your report as a guide and explore this area of sky. Thanks for highlighting it !

 

Enjoy that John.  Had a quick stroll round the village green earlier and it seems a bit darker tonight so hope you get a good session!

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Thanks - I've picked off the globulars NGC 7006 + 6934 plus the small planetary neb NGC 6891 so far. Got distracted by M71 in Sagitta and M27 in Vulpecula for a while though, which was very un-disciplined :rolleyes2:. Back to the Dolphin area again now.

 

 

 

Edited by John
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I like to choose a small constellation, and scan all it contains per my Sky Atlas 2000. I didn't know, but an unexpected benefit arises from these systematic deep dives during which I don't see most of the targets, or they remain just barely detectable: it makes the showpieces look so terrific they're scary.

The most vivid memories of this come from Andromeda and M3 many years ago: after long and mostly unsuccessful hunts for faint galaxies, I wanted to end the sessions with something easy, as a reward for the strain. First the "faint" outlying mist of Andromeda looked brighter and larger than usual, then the oval hub and the nucleus struck me as much, much more impressive than usual.

Same for M3: I had often found it not that striking, or too washed out by light pollution, or not enhanced enough by my scope of "only" five inches, blah-blah, negative blah-blah to myself. But after hours spent pulling out of the not-so-dark sky small fuzzies, so faint they're only traces, I truly understood how great M3 is. Its size is gigantic, its stars are obvious, its presence is imposing, but I never knew because I had not compared.

After that kind of revelation, you will never call the showpieces faint again, not even if your sky is subpar. Everyone should do that comparo regularly to keep things in perspective, because seeing only the main fuzzies makes them dull in time, but it's not their fault.

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8 hours ago, Ben the Ignorant said:

I like to choose a small constellation, and scan all it contains per my Sky Atlas 2000. I didn't know, but an unexpected benefit arises from these systematic deep dives during which I don't see most of the targets, or they remain just barely detectable: it makes the showpieces look so terrific they're scary.

The most vivid memories of this come from Andromeda and M3 many years ago: after long and mostly unsuccessful hunts for faint galaxies, I wanted to end the sessions with something easy, as a reward for the strain. First the "faint" outlying mist of Andromeda looked brighter and larger than usual, then the oval hub and the nucleus struck me as much, much more impressive than usual.

Same for M3: I had often found it not that striking, or too washed out by light pollution, or not enhanced enough by my scope of "only" five inches, blah-blah, negative blah-blah to myself. But after hours spent pulling out of the not-so-dark sky small fuzzies, so faint they're only traces, I truly understood how great M3 is. Its size is gigantic, its stars are obvious, its presence is imposing, but I never knew because I had not compared.

After that kind of revelation, you will never call the showpieces faint again, not even if your sky is subpar. Everyone should do that comparo regularly to keep things in perspective, because seeing only the main fuzzies makes them dull in time, but it's not their fault.

Beautifully put, Ben.

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On 04/10/2016 at 10:29, chiltonstar said:

There are some nice doubles too......... try Gamma Del and Struve 2735.

Chris

Thanks Chris - got the Tak out now waiting to have a go at these :icon_biggrin:

Edited by John
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14 hours ago, John said:

Thanks Chris - got the Tak out now waiting to have a go at these :icon_biggrin:

Amazing slight colour difference between the two components of Gamma Del, isn't there? Orange - blueish white with my 127 Mak at x150, orange-white with the 180 Mak also at x150. How does it look through the Tak?

Chris

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