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  #41  
Old 22-01-2009, 07:24 PM
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ngcles
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Hi Glen & All,

That is a very nice image of IC 5249 in particular.

I can remember observing this field about 4 years ago with the 18" at Mudgee and I was sure I'd made notes, but on searching my log, I only found a 31cm observation from Bargo on a very good night with a ZLM of 6.4 and good seeing back in 2001.

x186 26' TF.

IC 5250, IC 5250A (PGC 69714), IC 5246, NGC 7358, IC 5249 and IC 5247 all appear in the one group over 2 fields.

IC 5250 Mag 12.1p Size 2.9'. IC 5250 and -50A are a merged halo that contain distinctly seperate nuclei, -50 is the W most of the pair and the fainter. The combined halo is 1.75' x .25' in PA 90, rises broadly and slightly to the -50 nuclei, with the halo containing no apparent zoning except for the small 10" diameter moderately brighter spot core/nucleus.

PGC 69714 (IC 5250A) Mag 12.2p Size 2.7'. IC 5250 and -50A are a merged halo that contain distinctly seperate nuclei, -50 is the W most of the pair and the fainter. The combined halo is 1.75' x .25' in PA 90. The E end contains the -50A condensation, which is the brighter and is about 30-40" apart in PA 90. Rises broadly and moderately to the -50A nuclei which contains a 10" moderately brighter spot type core/nucleus which is somewhat brighter than the counterpart.

IC 5246 Mag 14.7 Size 1.0' x 0.6'. This eg is 10' N of the IC 5250 pairing. From that pairing, about 8' due N is a longish, thin RA Tri of mag 12-13 *s, to the NW of this is a rectangle of mag 13 *s which is about 5' x 2'. in PA 0. -46 appears to the W of the Tri and S of the rectangle. This is the 2nd brightest of the group (treating -50 as one object). This eg is pretty straightforward to see, round moderately faint, maybe 40" diameter rising slightly to the centre.

To the NE 5' and running beside the rectangle is IC 5249. IC 5249 Mag 15.0 Size 1.3' x 0.4'. A very small weak glow in PA 120, this is a very difficult eg to see and only occasinally visible as just about the thinest thing I've yet seen, it appears as 3' x <5" with the width of a strand of hair. No brightening to the axis or otherwise is detected. At the W end of the tip is a mag 15.5 *.

NGC 7358 Mag 13.8b Size 1.9' x 0.5'. Found 8' SW of IC 5250, there is a line of 4 faint *s in PA 45, the 3rd brightest is mag 13 and this eg appears very near it to the SE. Elongated in PA 170, 50" x 20", moderately faint and rising broadly and slightly to the centre.

IC 5247 Mag 15.0 Size 1.3' x 0.4'. A very small weak patch in PA120, 30" x 20" with a weak central brightening. Very faint it is , 15' SE of NGC 7358.


I can remember the night at Mudgee with the 18" (in July I think) and IC 5249 was just about the most beautiful, faint straight slash of gossamer imaginable -- really lovely. Dunno why I didn't do notes. Being July it maybe that it was very, very late (early) and had run out of motivation to make notes.

So Dunlop saw IC 5250 but not NGC 7258 and J Herschel missed the lot eh !

None of 'em are bright (well IC 5250 isn't too bad) and it is not entirely surprising they could be passed over.


Thanks Glen!



Best

Les D
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  #42  
Old 23-01-2009, 05:53 AM
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glenc (Glen)
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Thanks Les for the notes. Herschel probably missed IC5250 because he was busy making notes on h3953 = NGC7358.
PGC 47847 (mag 10.6) is another long thin galaxy. It is 2.4 degrees NE (pa36) of omega Cen. The attached wikisky.org image is 28' x 28'
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Last edited by glenc; 23-01-2009 at 06:05 AM.
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  #43  
Old 03-02-2009, 05:28 AM
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glenc (Glen)
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oc Dunlop 224

The open cluster Dunlop 224 = Harvard 6 is about 45' north of alpa in Musca.
Dunlop found it in 1826 and described it as " An exceedingly faint nebula, extended in the direction of the meridian, about 4' or 5' in length, with a line or group of very small stars in it."
He found about 20 non NGC/non IC open clusters. They were not included in the NGC because John Herschel failed to see them.
The attached wikisky.org image shows beta Mus top left, H6 and alpa Mus lower right.
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Last edited by glenc; 03-02-2009 at 05:43 AM.
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