Thunderhead
professor emeritus
Reged: 08/27/05
Loc: Melbourne, Australia
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Southern Globulars
#2240315 - 03/06/08 04:36 PM
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Havent seen many globular clusters so I decided to have a go at some.
Had the sky atlas 2000 out with me, great for quick improptu sessions like this.
Scope: 10" GSO dob
Time: 3.45am-5.30am
Seeing: 4/10
Transparency: 4/5
NGC 6397
Showed good resolution at 56x. At 192x the outer reaches appeared quite loosely bound, with a granular/hazy core. A circlet of several cluster members could be seen surrounding the core, with a red star among them. Increasing power to 250x bought out an additional 3-4 stars overlapping the core. Didn't expect to use such a magnification in light of the *BLEEP* seeing. But yes, it's a fine sight!
NGC 6584
Smaller globular in Telescopium, east of Ara. At 56x it is a hazy orb and forms a neat triangle with two 7th mag stars. At 192x, about half a dozen stars were resolved, increasing power to 250x added a few more to the tally.
NGC 5286
Located just 4' NW of mag 4.7 M Centauri. Outer areas were well resolved at 250x, with some further stars superimposed across the granular core.
M4
Very easily resolved, even at 56x. Very nice at 192x. Doesn't have much of a condensed core although a bar which is unevenly populated by mag 11 stars crosses its center. A nice arc of 18 mag 11-13 stars "cradles" the cluster's western side.
NGC 6144
A faint ghost about 40' NW of Antares. A mag 12 star marks the W edge. At 192x I could resolve perhaps 10 faint cluster members.
M80
Still in the vicinity of Antares, NW of M4. Several stars across the outer half were resolved at 250x, with a bright condensed core.
NGC 6752
Apparently this is supposed to be the 4th best globular in the sky, am I correct? Located in Pavo almost midway between Peacock star and Ara. A mag of 192x bought out lovely arcs of bright stars streaming from the core, with a circlet of cluster members also present. The tight core showed granularity.
M22
Just a quick peek at 192x in morning twilight, now i see what all the fuss is about!
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desertrefugee
Carpal Tunnel
Reged: 08/06/07
Loc: Arizona
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Re: Southern Globulars
[Re: Thunderhead]
#2240369 - 03/06/08 04:57 PM
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M22
Just a quick peek at 192x in morning twilight, now i see what all the fuss is about!
Yup. M22 is one of my favorite all time objects.
(Although my recent first glimpse of Omega Centauri (at about 10* elevation) makes me rethink that position).
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sgottlieb
scholastic sledgehammer
Reged: 07/22/07
Loc: SF Bay area
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Re: Southern Globulars
[Re: Thunderhead]
#2240604 - 03/06/08 06:48 PM
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Apparently this is supposed to be the 4th best globular in the sky, am I correct? Located in Pavo almost midway between Peacock star and Ara. A mag of 192x bought out lovely arcs of bright stars streaming from the core, with a circlet of cluster members also present. The tight core showed granularity.
Unfortunately, this globular is very low or below the horizon for U.S. observers, but it is a beauty. Here are my notes from Australia...
NGC 6752 is one of the top globular clusters (4th brightest in integrated magnitude and 2nd in terms of brightest members) and was spectacular in the 18-inch f/4.5 at Magellan Observatory. At 128x, this naked-eye cluster seemed fully resolved with an uncountable number of stars densely packed over a large region. Streamers in the halo greatly extend the outer extent to roughly 20'. The central region is well-compressed to a very bright core. There is a strong 3-dimensional effect as the core is covered with scores of fairly bright stars that are seemingly superimposed over a rich mat of fainter stars and all set over a background glow. The nucleus is small and very bright. Many 11th-12th magnitude stars in the halo form complete loops and long chains. A mag 7.7 double star is superimposed on the SW edge of the halo (h5085 = 7.7/9.2 at 2.8").
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Tony Flanders
Postmaster
Reged: 05/18/06
Loc: Cambridge, MA, USA
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Re: Southern Globulars
[Re: Thunderhead]
#2241741 - 03/07/08 10:40 AM
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NGC 6752
Apparently this is supposed to be the 4th best globular in the sky, am I correct?
Gosh, people fight enough about which globular is best; you'll never get consensus on fourth-best. If NGC 6752 is number four, what's number three? M22?
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sgottlieb
scholastic sledgehammer
Reged: 07/22/07
Loc: SF Bay area
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Re: Southern Globulars
[Re: Tony Flanders]
#2242527 - 03/07/08 05:01 PM
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you'll never get consensus on fourth-best. If NGC 6752 is number four, what's number three? M22?
I have a feeling, Tony, that the comment was simply based on NGC 6752 being ranked 4th in total integrated V magnitude (V = 5.5) though of course the visual impact is more of a personal reaction as you mentioned. M22 does squeeze in ahead at V = 5.2.
In terms of the brightest individual stars, I believe that NGC 6397 in Ara holds that title.
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Rodstar
member
Reged: 11/19/07
Loc: Central Coast, NSW, Australia
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Re: Southern Globulars
[Re: sgottlieb]
#2247493 - 03/10/08 03:53 AM
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I'd thoroughly recommend NGC 2808 to anyone cruising through the southern constellation of Carina. I was admiring it on Sasturday night under rural skies in my 20" SDM scope, and it truly is a show stopper. It is like a condensed version of Omega Centauri. It was beautifully framed in the Ethos at 195x
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sgottlieb
scholastic sledgehammer
Reged: 07/22/07
Loc: SF Bay area
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Re: Southern Globulars
[Re: Rodstar]
#2248664 - 03/10/08 05:27 PM
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I'd thoroughly recommend NGC 2808 to anyone cruising through the southern constellation of Carina. I was admiring it on Sasturday night under rural skies in my 20" SDM scope, and it truly is a show stopper. It is like a condensed version of Omega Centauri. It was beautifully framed in the Ethos at 195x
Another pair of southern globulars that don't seem to get a lot press -- NGC 4372 and NGC 4833 in Musca. Both of these are 7th magnitude globulars and wonderful objects in larger scopes. Here are my last notes on NGC 4372 using an 18" from Australia --
At 171x, this large, bright globular was an impressive object and beautifully resolved into 150-200 stars mag 13 and fainter within a 13'-14' diameter. The unresolved background glow was relatively faint for such as a well-resolved globular. The large 4' core is only slightly brighter and there is no nucleus (class 12 concentration) although a close pair of brighter mag 12.5 stars is near the center. Scores of stars appear linked in chains and loops, particularly in the outer halo, which is quite irregular and ragged. Mag 6.6 HD 107947 lies 5.5' NW of center at the edge of the halo and provides a striking contrast although it detracts somewhat from viewing. A dust lane appears to pierce the cluster on the north side for a few arc minutes (east of the bright star) and this dark intrusion may be an extension of the "Dark Doodad".
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Stephen65
scholastic sledgehammer
Reged: 04/14/07
Loc: Melbourne, Australia
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Re: Southern Globulars
[Re: sgottlieb]
#2249532 - 03/10/08 11:41 PM
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Yup. M22 is one of my favorite all time objects.
(Although my recent first glimpse of Omega Centauri (at about 10* elevation) makes me rethink that position).
Just wait till you get far enough South to see 47 Tuc.
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Dave Mitsky
Postmaster
Reged: 04/08/02
Loc: PA, USA, Planet Earth
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Re: Southern Globulars
[Re: Stephen65]
#2249797 - 03/11/08 03:41 AM
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These are my favorite globular clusters:
1. NGC 5139 (Omega Centauri)
2. NGC 104 (47 Tucanae)
3. M22
4. NGC 6397
5. NGC 6752
6. M13
7. M4
8. M5
9. M3
10. M55
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FirstSight
Postmaster
Reged: 12/26/05
Loc: Raleigh, NC
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Re: Southern Globulars
[Re: Tony Flanders]
#2250417 - 03/11/08 01:01 PM
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NGC 6752
Apparently this is supposed to be the 4th best globular in the sky, am I correct?
Gosh, people fight enough about which globular is best; you'll never get consensus on fourth-best. If NGC 6752 is number four, what's number three? M22?
Oh, but what a fun fight to train for by doing some personal field research, and then...BRING IT ON! Like a wrestling match in a foot-deep pit full of jello globs, who cares who actually *wins* the fight, so long as you're there to see it for yourself! Only much better with stellar globular clusters than with globs of jello.
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sgottlieb
scholastic sledgehammer
Reged: 07/22/07
Loc: SF Bay area
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Re: Southern Globulars
[Re: Dave Mitsky]
#2250665 - 03/11/08 03:17 PM
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These are my favorite globular clusters...
It definitely gets slighted because it's overshadowed by 47 Tucanae, but NGC 362 located just north of the Small Magellanic Cloud is a great glob in its own right.
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gripweed44
Pooh-Bah
Reged: 02/12/05
Loc: PDX
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Re: Southern Globulars
[Re: sgottlieb]
#2259768 - 03/15/08 06:14 PM
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Hi
I just returned from Hawaii and got my first look at Omega Centauri.
All I can say is WOW!
Whether naked eye, in my 10x50 binocs or in my 80mm Apo it was the biggest Glob I have ever seen. I saw many doing the AL Globular award.
What a joy it was. Wish I had a big dob to look through
John
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boatstar
super member
Reged: 04/10/05
Loc: Cowtown, Texas
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Re: Southern Globulars
[Re: gripweed44]
#2277725 - 03/23/08 11:21 PM
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Hey Weed,
We were just looking at it just a couple of weeks ago with a 30" Obsession and a 31mm Nagler out in West Texas. It was overwhelming. I'm not sure that this target isn't best appreciated through binos or richfield gear.
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gripweed44
Pooh-Bah
Reged: 02/12/05
Loc: PDX
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Re: Southern Globulars
[Re: boatstar]
#2277751 - 03/23/08 11:40 PM
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It was huge and I mean Huge in the Binocs. Four times the size of M4. Which by the way - I got naked eye as well in Volcano, HI
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