Is Pal 11 a viable visual target
Pal 11 in Aquila
Posted 03 September 2013 - 04:19 AM
Is Pal 11 a viable visual target
Posted 03 September 2013 - 07:50 AM
Posted 03 September 2013 - 12:55 PM
18" (7/14/07): swept up at 150x as a very low surface brightness hazy region, ~3' in diameter with a few mag 15+ stars superimposed. Cradled by three mag 13 stars close southwest, east and northeast. A 22" pair of mag 11.5/12 stars lie ~3.5' N. The observation was interrupted before I could use higher power to resolve.
18" (8/2/05): easily picked up in the field at 115x. At 160x appears as a fairly large, very low surface brightness glow, perhaps 3.5' diameter though the periphery fades into the background and is not easily traced visually. The cluster is nestled adjacent to a group of mag 13 stars and a 22" pair of mag 12 stars is to the north. The surface brightness is irregular or mottled and several extremely faint stars pop in and out of visibility at this power including a few stars near the center. Located 4' SSE of mag 8.6 HD 186496.
18" (7/19/04): at 225x, appears faint, moderately large, round, ~3'-3.5' diameter with almost no central brightening although the globular fades around the periphery. Several faint stars are superimposed. It was difficult to estimate the size as the halo is not well defined. At times I felt the diameter was as large as 6' but sometimes appeared 3' at most. At 435x, a half dozen faint stars are superimposed though some may be foreground stars (the brightest cluster members are mag 15.5). The cluster's surface brightness is quite low at the magnification.
17.5" (8/21/98): visible at 100x as a diffuse, irregular glow 4' SSE of mag 9 SAO 143755 and nestled to the SW of a group of mag 12-14 stars. At 220x, the diameter is 3.5'-4' and the surface appears mottled. Several faint stars were resolved (or superimposed) with averted vision over a ragged glow.
17.5" (7/4/86): faint but easily visible. Appears as a large hazy region best seen at 83x. Some faint stars are superimposed and a nice double star is just N.
Posted 03 September 2013 - 04:30 PM
And yes, like David and Steve said it is visible and one of the more simpler ones of the Palomar catalog. I tried to translate my Palomar GC project into English, sorry for the bad phrasing.
From the project about Pal 11 I have 4 observations with different aperture:
16", 257x, fst 7m+
faint, circular, also visible with higher power, 3 stars glimpsed through the halo, no other structure
20", fst 7m+
bright, can easily seen with lower magnification, with higher magnification a dozen of stars can be seen
24", fst 7m0
bright, circular, spectacular resolution into a couple of dozens of stars
27", 293x, fst 7m+
bright and remarkably glow; without an clearly concentration; with 293x a dozen stars pops out the mottled glow; brightest stars form a square figure near the middle of the GC
Posted 03 September 2013 - 10:27 PM
Posted 04 September 2013 - 06:21 PM
Posted 12 September 2013 - 05:33 PM
Posted 13 September 2013 - 01:08 AM
4.5" reflector @ 304x: Fairly faint, round, unresolved, slightly mottled with averted vision? Two/three extremely faint stars visible near the center.
Posted 13 September 2013 - 04:48 AM
Posted 13 September 2013 - 11:12 PM
I've seen both Pal 13 and Pal 10 before with a 17.5", but Pal 11 seemed just beyond the reach of the 12.5".
Posted 17 September 2013 - 11:48 AM
24" (9/7/13): at 200x this relatively bright Palomar globular contained a brighter core and a roundish halo ~2.5' diameter, with several mag 15 and fainter stars resolved. Well resolved at 375x and 500x into roughly two dozen mag 15/16 (several extremely faint) stars resolved in addition to 5 brighter mag 14.5-15 stars. The resolved stars are distributed over the entire glow, though more concentrated in a 1' core that is slightly elongated SW to NE. Situated 4' SE of mag 8.6 HD 186496 with several brighter mag 12-13 stars scattered outside the halo of the cluster.
Posted 25 September 2013 - 07:05 AM
Roy in Taos.
Posted 25 September 2013 - 08:54 AM
Posted 25 September 2013 - 11:01 AM
It's tough, but possible to observer visually if you have dark skies and a large telescope. Even then, I was not able to see it from the Gulf Coast region of the U.S. even with a 15-inch. If you find it, it will be a dim, unresolved glow, like all of the other Palomar globular clusters. They are challenge objects, but nothing like the showpieces M-22 or M-13 are.
I think I was looking for the wrong thing - a tight ball of stars. If it appears as just a dim glow, then I probably saw it but didn't recognize it as a globular cluster.