· Get a Cloudy Nights T-Shirt · Submit a Review / Article Click here if you are having trouble logging into the forums Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User You are not logged in. [Login] Entrance · Main Index · Search · New user · Who's Online FAQ · Calendar Astrophotography and Sketching >> Sketching Previous   Index   Next   Threaded   Pages: 1 | 2 | (show all) Jef De Wit Carpal Tunnel Reged: 03/06/09 Loc: Hove, Belgium A globular with spiral structure?       #5341172 - 07/29/12 05:37 AM Attachment (95 downloads) Edit   Reply   Quote Quick Reply   We had some clear nights in Belgium. I sketched some asterisms and one globular cluster. Lord Rosse saw spiral structure in M92 (the other globular cluster in Hercules). I could dedect only one "spiral arm": a nice row of stars starting from the south side and curving to the east side. 12" @ x240, FOV +/- 20', SQM 19.2 Post Extras:       Jef De Wit Carpal Tunnel Reged: 03/06/09 Loc: Hove, Belgium Re: A globular with spiral structure? [Re: Jef De Wit]       #5341175 - 07/29/12 05:43 AM Attachment (64 downloads) Edit   Reply   Quote Quick Reply   Of the six asterism I sketched, this one was the nicest. Poskus 1 is a small but fine asterism that looks like a fly swatter. It is situated 10' northwest from the nice double Gamma Delphinus. Both objects are a beautiful sight. Check it out! 12" @ x92, FOV +/- 40', SQM 19.0, not all field stars are sketched Post Extras:       curiosidad sage Reged: 06/09/11 Re: A globular with spiral structure? [Re: Jef De Wit]       #5341196 - 07/29/12 06:22 AM Edit   Reply   Quote Quick Reply   You are an Artist! Post Extras:       maroubra_boy sage Reged: 09/08/09 Loc: Sydney, Australia Re: A globular with spiral structure? [Re: curiosidad]       #5341224 - 07/29/12 07:14 AM Edit   Reply   Quote Quick Reply   What a lovely quirky signature feature you've noted Jef. I love picking out these special features in globulars. Give each GC its own unique charateristics. Post Extras:       Ed D Carpal Tunnel Reged: 04/30/10 Loc: Sunny South Florida Re: A globular with spiral structure? [Re: maroubra_boy]       #5341310 - 07/29/12 08:53 AM Edit   Reply   Quote Quick Reply   Two very nicely done sketches. I also learned something new about M92. Thanks!!! Ed D Post Extras:       frank5817 Postmaster Reged: 06/13/06 Loc: Illinois Re: A globular with spiral structure? [Re: Ed D]       #5341556 - 07/29/12 12:24 PM Edit   Reply   Quote Quick Reply   Jef, Very fine sketch of M92 and the fly swatter, I CAN SEE IT-COOL! Frank Post Extras:       Rutilus Pooh-Bah Reged: 12/17/10 Re: A globular with spiral structure? [Re: frank5817]       #5341813 - 07/29/12 03:10 PM Edit   Reply   Quote Quick Reply   Excellent work Jef. Post Extras:       GlennLeDrew Postmaster Reged: 06/18/08 Loc: Ottawa, Ontario, Canada Re: A globular with spiral structure? [Re: Rutilus]       #5341996 - 07/29/12 04:57 PM Edit   Reply   Quote Quick Reply   To address the question posed in the title, it is of course impossible for a globular--or any cluster--to posses any kind of spiral structure. By their nature, the orbits of the member stars are randomly oriented, with the whole population very quickly well mixed. Any apparent alignments would be transitory, and certainly not coherent in the third dimension. And of course, the visual system is quite adept at picking out such alignments, as though it were a fundamental characteristic to discern organized patterns. Post Extras:       niteskystargazer Carpal Tunnel Reged: 10/05/09 Loc: 41-43'-28" N 87-42'-39" W Re: A globular with spiral structure? [Re: Jef De Wit]       #5342035 - 07/29/12 05:19 PM Edit   Reply   Quote Quick Reply   Jef, Very good sketch of M-92 . CS,KLU, , Tom Post Extras:       JeanB Pooh-Bah Reged: 07/11/11 Loc: Montreal, Canada Re: A globular with spiral structure? [Re: niteskystargazer]       #5342524 - 07/29/12 10:41 PM Edit   Reply   Quote Quick Reply   Jef, you are at the top of your art!!! Jean Post Extras:       Jef De Wit Carpal Tunnel Reged: 03/06/09 Loc: Hove, Belgium Re: A globular with spiral structure? [Re: JeanB]       #5343313 - 07/30/12 12:20 PM Edit   Reply   Quote Quick Reply   Thanks you guys for the nice comments. Thanks Glenn, for the astrophysics. Post Extras:       mike73 member Reged: 05/01/12 Loc: UK Plymouth Re: A globular with spiral structure? [Re: Jef De Wit]       #5344610 - 07/31/12 02:48 AM Edit   Reply   Quote Quick Reply   Very tidy sketches Jef and I really like how you picked out the asterism in M92. I've been reading Stephen O'Meara's Messier Objects and he does exactly the same. When you really look all globulars are very different. Post Extras:       Mizar76 member Reged: 01/07/11 Loc: Rome, Italy Re: A globular with spiral structure? [Re: mike73]       #5346452 - 08/01/12 05:49 AM Edit   Reply   Quote Quick Reply   Very very nice work Jef! Compliments!!! Stefano Post Extras:       observing1 sage Reged: 03/22/11 Re: A globular with spiral structure? [Re: Mizar76]       #5347595 - 08/01/12 07:59 PM Edit   Reply   Quote Quick Reply   I went to an astronomy tour in Arizona, and looked through a pro's telescope at M3, which is a globular. I was very convinced it looked spiral, but everyone told me globular clusters can't be spiral. I'm stumped too. Post Extras:       Jef De Wit Carpal Tunnel Reged: 03/06/09 Loc: Hove, Belgium Re: A globular with spiral structure? [Re: observing1]       #5348193 - 08/02/12 05:36 AM Edit   Reply   Quote Quick Reply   Mike & Stefano: @ observing1: I never looked at M3 with a big scope, but will keep it in mind for a next visite. Post Extras:       phily sage Reged: 12/18/04 Loc: Kent, UK Re: A globular with spiral structure? [Re: Jef De Wit]       #5358214 - 08/08/12 02:52 PM Edit   Reply   Quote Quick Reply   Very interesting sketch, very nicely done. Lovely clear sky! Phil Post Extras:       geminijk professor emeritus Reged: 04/03/08 Loc: TN Re: A globular with spiral structure? [Re: phily]       #5362759 - 08/11/12 01:04 AM Edit   Reply   Quote Quick Reply   Beautiful sketches! I never noticed it with M92, but M5 always sees to remind me of a spiral. John Post Extras:       Andrev Carpal Tunnel Reged: 02/08/11 Loc: Montreal, Quebec, Canada Re: A globular with spiral structure? [Re: geminijk]       #5362889 - 08/11/12 05:59 AM Edit   Reply   Quote Quick Reply   Jef. Well, you just me curious to see both now. I never remarked any spiral looking effect in M92, but for sure I'll pay more attention next time. And your second asterism is very interesting. The double star look very interesting too. I have to check that. Thanks for sharing. Beautiful sketches. Andre. Post Extras:       Andrev Carpal Tunnel Reged: 02/08/11 Loc: Montreal, Quebec, Canada Re: A globular with spiral structure? [Re: Andrev]       #5363393 - 08/11/12 01:58 PM Edit   Reply   Quote Quick Reply   Jef. I'm trying to find the Delphinus in Sky Tools and I can't see it ??? Very strange. You said you FOV is 40' as shown on the picture ? Which range of mangitude are the stars ? Andre. Post Extras:       mdowns Pooh-Bah Reged: 06/12/10 Loc: Englewood,FL Re: A globular with spiral structure? [Re: Jef De Wit]       #5363567 - 08/11/12 04:26 PM Attachment (27 downloads) Edit   Reply   Quote Quick Reply   Jef De Wit It took me forever to find this scetch I did 30 years ago with a 10" dob about 20 miles east of Indianapolis. Interestingly the stars in my field look very different than yours.Maybe I mislabled this one but I think I was very sensitive to yellow stars.I recall my observing buddy always saying that a star I said was bright would seem faint to him. Nonetheless I do show a curving arc of stars that might be thought of as a portion of a spiral. Post Extras:       Jef De Wit Carpal Tunnel Reged: 03/06/09 Loc: Hove, Belgium Re: A globular with spiral structure? [Re: mdowns]       #5374830 - 08/18/12 02:58 PM Attachment (27 downloads) Edit   Reply   Quote Quick Reply   Thanks, all! I was two weeks on holiday (without internet), so sorry for the late reaction... @ John: I never observed M5 with a big scope, but will keep it in mind. @ Andre: Poskus 1 is small (6,5') and weak (I guess stars around mag 13-14). It is situated some 10' northwest of Gamma Del. Maybe this 30' wide photo of DSS can help. Edited by Jef De Wit (08/18/12 02:59 PM) Post Extras:       Andrev Carpal Tunnel Reged: 02/08/11 Loc: Montreal, Quebec, Canada Re: A globular with spiral structure? [Re: Jef De Wit]       #5390909 - 08/28/12 06:19 AM Edit   Reply   Quote Quick Reply   Jef I pointed M92 last saturday and I clearly saw the spiral look of this glob. Very nice one. Thanks for pointing this particularity. Andre. Post Extras:       rodelaet Post Laureate Reged: 04/28/06 Loc: 50°56' N - 4°58' E (Belgium) Re: A globular with spiral structure? [Re: Jef De Wit]       #5395990 - 08/31/12 01:35 AM Edit   Reply   Quote Quick Reply   Speaking of spiral structure, the one object that amazed me with a spiral 'feature' was ... an open cluster! Have you ever looked at M25 with a pair of binoculars? Clear skies, Post Extras:       Pages: 1 | 2 | (show all) Previous   Index   Next   Threaded   Extra information 1 registered and 8 anonymous users are browsing this forum. 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