#1  
Old 30-06-2008, 11:30 PM
ngcles's Avatar
ngcles
The Observologist

ngcles is offline
 
Join Date: Dec 2006
Location: Billimari, NSW Central West
Posts: 1,664
Observation Report 28 June 2008 NGCLes

Hi All,

Here are some observations from the other night at my regular "nearly dark" site in the southern highlands. It was a curious old night cloud-wise. Clear when I arrived, by the time I set up at about 7.30pm there was considerable high cloud which sort of came and went all night with some quite good patches in between, but it closed out completely at about 10.30pm.

I waited till 11.30 and gave in. Of course by the time I had completed packing everething back into the vehicle at 11.50pm, it was completely clear and I drove home under an unsullied sky. The SQM readings hovered between 20.9 and 21.05 and the seeing was pretty good without being outstanding -- a good 6/10 and sometimes 7/10.

Jupiter was also observed for some time and was really nice at x185 and x247, though it was a tad soft at the higher power. It seems to me that sincle last year the Eq zone is somewhat whiter than it has been for some time, and the NEB seemed to have a lot of slightly lighter swirly spots and waves within it. Really beautiful.

Beside that, apart from poking around at some favs, I decided to make some observations of some brighter winter GCs that I hadn't recorded with the 18" before, and also NGC 6309. For a change, all are relatively bright objects!

Here are the observations:

x185 27' TF
x247 20' TF

NGC 6362 Globular Cluster *
RA: 17h 31m 54.8s Dec: -67° 02' 53"
Mag: 8.1 Mag V(tip): 12.7 Mag V(HB): 15.3 B-V (tip): ---
Size: 15.0' Class:

This is a largish, fairly bright but weakly concentrated globular in a moderately populated field. Overall it would seem about 9' diameter and circular. The brightest member stars seem about mag 13 or a fraction fainter and there are probably in excess of 100 *s resolved. The edges of the cluster are not well defined and it is broadly and weakly to slightly concentrated. There is a quite large only slightly more populous core zone about 6' diameter where most of the residual haziness is and it seems that some of the brighter resolved stars are in a line running N-S across the cluster -- 6 ot 7 stars involved and around centre it seems a bit clumpy in surface brightness with some small, slightly darker areas here and there. With the 12mm, there is a mag 7 * on the field stop to the NNE.


x185 27' TF
x247 20' TF

NGC 6352 Globular Cluster *
RA: 17h 25m 29.2s Dec: -48° 25' 22"
Mag: 7.8 Mag V(tip): 13.4 Mag V(HB): 15.2 B-V (tip): --- Size: 9.0'

This cluster seems to have a brighter integrated magnitude that NGC 6362 (nearby) bt doesn't seem as bright in the ep. Though certainly not as large, 6-7' diameter and not as well resolved -- the brightest are about mag 13.5 or a tad worse. Broadly and slightly concentrated from indefinite edges within a quite populous field. The core is about 3.5' diameter, and only weakly brighter than the remaining outer halo and this is where most of the resolved *s are. At x247, most of the cluster is grainy and there are about 50 odd resolved stars that are a bit "clumpy" toward centre and the surface brightness of the background halo is uneven in the core. Around the southern edges of the core zone there seems to be a few small dark blobs that have a similar SB to the background sky rather than the core of the cluster.


x185 27' TF
x247 20' TF

NGC 6584 Globular Cluster *
RA: 18h 18m 37.7s Dec: -52° 12' 54"
Mag: 7.9 Mag V(tip): 13.5 Mag V(HB): 16.5 B-V (tip): --- Size: 6.6' Class:

x247: Suspect I am viewing through thin high haze Seems about 4 - 4.5' diameter which sits within a crooked "L" shaped asterism of 3 mag 11 and a mag 12 *. It is broadly and mod compressed to centre with quite a number of faint resolved *s here and there around the periphery though it is not clear they are member stars. Those stars on the boundary seem to make the cluster centre core appear a little off-set to the SE at first lance, though this is probably illusory. Not particularly well resolved, maybe 20 - 30 *s faint members about 14th mag mainly in the outer halo, with one or two perhaps a bit brighter than that. The balance is a bit granular though mostly plain hazy in texture with an est cc of 6 or 7. No really well defined core zone.


x185 27' TF
x247 20' TF
x317 15' TF

M 54 NGC 6715 Globular Cluster *
RA: 18h 55m 03.3s Dec: -30° 28' 42"
Mag: 7.7 Mag V(tip): 15.2 Mag V(HB): 18.2 B-V (tip): --- Size: 12.0' Class:

With the 12mm, the cluster is pretty small, only 3' diameter with very high SB and is bright in the ep and well concentrated. The bulk of the cluster sits within a small tri of mag 13.5 *s on the E, W and another on the S that is inside the halo. Doesn't look very grainy at x185, but is bright, high SB and strongly concentrated. Est cc 4, mod and evenly to the centre With the 7mm and x317 it is more interesting, it looks like a 1/2 scale version of NGC 362. Concentrates mod and evenly to centre and at the very centre sharply, though there is no strongly delineated core zone. Maybe nearly 4.' diameter with ill-defined edges stretching to just outside those stars on the E and W side. In moments of good seeing it is pretty grainy and seems there are many occasionally visible threshold points, more evident about 1/2 way out in the halo.



x185 28' TF
x247 20' TF

M 69 NGC 6637 Globular Cluster *
RA: 18h 31m 23.2s Dec: -32° 20' 53"
Mag: 7.7 Mag V(tip): 13.7 Mag V(HB): 15.9 B-V (tip): --- Size: 9.8' Class:

This GC appears in a pretty well populated field with lots of 12th and 13th mag *s. Seems to be about 4.5' to 5' diameter with a broad, slight to moderate concentration to the centre. The core zone is not well defined but seems about 3' diameter and overall it seems to show pretty good resolution. Looking at the background the cluster is in, some of the apparent members are probably superimposed *s but not all. Member *s seem to start at low 13s or early 14s and in moments of good seeing there are 20 or 30 of those, maybe 50??. The rest looks slightly granular or mottled in places. Est cc 9??


x247 20' TF
x317 15' TF

NGC 6309 Planetary Nebula *
RA: 17h 14m 04.5s Dec: -12° 54' 41"
Mag: 10.8 (P) Size: 16.0" Class: 3b+6 Mag C. Star: 16.5

This is a quite small quite elong PNe, very nice. Quite a curious shape -- as the moniker suggests it is rectangular elong in PA 0, appearing immediately S of a mag 12 *. Without the filter it is a nice light turquoise, reacts well to the UHC but seems a little dim to the OIII -- particularly at x317. Seems to be about 25" x 15" in PA 0, and at x317 the two lengthened ends have slight brightening within them and these ends have slightly higher surface brightness than the connecting section in the centre which is a little dimmer. Also the edges of the PNe are best defined at the two ends than the long sides. Not a particularly well populated field. Nice PNe. No sign of the central *.


x185 27' TF
x247 20' TF
x317 15' TF

M 70 NGC 6681 Globular Cluster *
RA: 18h 43m 12.7s Dec: -32° 17' 31"
Mag: 7.8 Mag V(tip): 13.0 Mag V(HB): 15.6 B-V (tip): --- Size: 8.0' Class:

x247 M70 is not too different from M69 with a similar looking sort of field, probably 4' diameter, est cc 5 and resolves similarly. At x247 there are 2 to 3 dozen *s that are resolved with little effort. The core zone seems 2.5' diameter and is mod brighter than the halo and there is a string of 4 or 5 resolved stars extending N out of the halo. Small clump of several, maybe 1/2 doz mags 13.5 - 14 *s almost dead-centre that at lower power looks like a spot or stellaring in the centre. Br *s are about mid 13s. Inner areas otherwise look slightly granular at times



x185 27' TF
x247 20' TF


NGC 6541 Globular Cluster *
RA: 18h 08m 02.2s Dec: -43° 42' 20"
Mag: 6.3 Mag V(tip): 12.1 Mag V(HB): 15.3 B-V (tip): --- Size: 15.0' Class:

This is a magnificent object that really should have made Messier's list -- I guess it is just a bit too far south for him to see. Doesn't loos a lot compared to M5 and overall it is pretty similar looking. Seems maybe 10' diameter with scattered outliers, Not easy to separate the edges of the cluster from the field stars -- pretty well populated field. From indefinite edges it grows mod and slightly and then at a point about 3' from centre mod and evenly and finally strongly to an intensely bright centre. 100s of resolved *s in total including right into the centre. Even in the central 1', there are about a dozen. Round. Really a beautiful object.

Best,

Les D
Contributing Editor
AS&T
Reply With Quote
  #2  
Old 01-07-2008, 06:49 AM
goober's Avatar
goober (Doug)
No obs, raising Harrison

goober is offline
 
Join Date: Nov 2007
Location: Melbourne, Australia
Posts: 795
Onya Les. Some objects I can relate to

Glad to see someone's out there. I'm starting to get Sab Syndrome (staring at the weather map and waiting, waiting, waiting....)
Reply With Quote
  #3  
Old 01-07-2008, 07:52 AM
cookie8's Avatar
cookie8 (Vincent)
Hooked since Halley's

cookie8 is offline
 
Join Date: Dec 2005
Location: Baulkham Hills,NSW
Posts: 790
Unhappy

Agree with you Les.
I was at Blackheath that night. Same high clouds all night apart from may be 45 mins clear sky. Heavy dew. Pack up 10pm.
Vincent
Reply With Quote
  #4  
Old 04-07-2008, 11:30 AM
Rob_K
Registered User

Rob_K is offline
 
Join Date: Oct 2006
Location: Bright, Vic, Australia
Posts: 2,158
Excellent stuff Les, really enjoyed your globular cluster descriptions! Fully agree with your comments on NGC 6541 - it's a beautiful object even in my little scope. Nice to get some obs - been very cloudy here this new moon, although today is a gem and augurs well for tonight... maybe!

Cheers -
Reply With Quote
  #5  
Old 04-07-2008, 01:39 PM
ngcles's Avatar
ngcles
The Observologist

ngcles is offline
 
Join Date: Dec 2006
Location: Billimari, NSW Central West
Posts: 1,664
Hi All,

Thanks guys.

Contrary to what might appear (sometimes) from my observing posts here, I don't just look at the tiny, the (nearly) invisible and the obscure. I spend at least as much time observing bright objects -- it's just that I've already "recorded" virtually all the bright ones in moderate and large apertures and when I see them for the 2nd, 3rd, 4th or nth time I don't do it all again -- at least without a reason.

In this case I'd never recorded these important G.Cs in the larger aperture, where they look so much more detailed and resolved, so I thought I'd better -- just in case I need the notes for later on.

To you "Mexicans", it won't stay cloudy forever -- don't give up. I remember a spell here in Sydney back in 1994 or 1995 (??) when we went for about 8 months with virtually unbroken overcast at night, almost every night. I even started looking at (gasp) the Moon (of course it was clear around full moon -- nearly always is). Anything, anything to cure my deprivation of photons.

Best,

Les D
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 01:10 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Advertisement
Testar
Advertisement
Bintel
Advertisement