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Old 23-05-2010, 01:43 PM
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ngcles
The Observologist

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Join Date: Dec 2006
Location: Billimari, NSW Central West
Posts: 1,593
Hi Paddy,

Great observing report -- very enjoyable. Yep M19 is quite oval elongated N-S and well resolved. Apparently this ellipticity is due to tidal interction with the core of the Milky Way that it passed recently (in context).

M9 is probably the least of the Messier Clusters in Ophiuchus but in a true dark sky with a large 'scope it is a rewarding object at moderate powers. Here's an observation I made of it in 2005 up at Mudgee on a night that was absolutely freezing in late June (it was minus 3 at the time) that includes LDN 173 that is adjacent.

x185 27' TF

One of the lesser Messier clusters in Ophiuchus, but none the less a splendid object which is well resolved. Seems to have lower CC -- perhaps 8-9 with a broad moderate concentration of stars toward the centre. It is partially to well resolved at x185 with perhaps over 100 mag 13 to threshold stars peppered over the face of the cluster which has a hazy grainy background. Appears perhaps 8-9' diameter. The two brightest resolved stars are 1/2 way out on the S side of the halo and in an apparent pair with a clump of fainter stars surrounding them. Overall seems round. There is a conspicuous large void of stars to the W and SW of the cluster which shows up better with low power -- this is B 64 or LDN 173.B 64

LDN 173Dark Nebula
RA: 17h 17m 19.2sDec: -18 31' 03"
Mag: ---Size: 12.0'x8.0'Class: Co
Appears 20' to the W and SW as an irregular shaped large 15' x 15' void with almost no faint stars within it.

There are quite a few faint but interesting galaxies in Ara and you've really only scratched the surface. Unfortunately, very few have NGC designations and can be a bit daunting. NGC 6300 is a bright barred-spiral well worth a look. But personally, though it is not spectacular visually (barely visible in 12") the pair of ESO 138-29 & -30 that is sometimes known as the "Toadstool Galaxy" a fantastic interacting pair of galaxies where a ring-form spiral has been created by a small dwarf plunging through the heart of the other. One to see just so you can say you've seen it ...


Best,

Les D
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