B 92 (LDN 323) and B 93 (LDN 327) Dark Nebulae in Sagittarius

Center of field at approximately: RA 18 hours 16 minutes 14 seconds, Dec -18 degrees 10 minutes 10 seconds

Size: 15' x 9.0' and 8.0' x 3.0' Magnitude: -- and -- Class: 6 E G and 4 Co G

Note: The small Open Cluster Cr 469 (Lund 818) is just below and between B 92 and B 93 at 18h 16m 34s, -18d 18m 39s

Size: 5.0' Magnitude: 9.1 Class: IV 1 p

North is up

West to the right

Telescope:

8" f5 Newtonian reflector

Camera:

 ST-8XME, self-guided, binned 1x1, temp -15c, camera control MaxIm DL 4.56

Image:

Lumicon Red filter, 460 minutes (46 x 10 minute subs), 08/24/25/26/27/2008; seeing 2.6-5.7 FWHM per CCDStack

Processing:

CCDStack 1.3.7, Photoshop 7.0

Location:

 Rolling Roof Observatory, Thousand Oaks, CA 91360 (+34d 13m 29s -118h 52m 20s)

Notes: These two dark nebulae are on the Northwestern edge of "M 24", which is really just a bright section of the Milky Way ... also known as the "Small Sagittarius Star Cloud". NGC 6603 is not M 24 ... The Messier object is actually IC 4715 ... according to the NGC / IC Project.

The group of stars that 'looks' like a cluster, located about 15 minutes due north of Cr 469,  may be SGR R1, an 'Association of Stars' ... However, the CDS Aladin Previewer gives the coordinates of 'SGR R1' as 18h 19m, -18d 00m, a position that is centered northeast of B 92 (see marked image). The approximate center of what looks like a cluster is 18h 16m 23.8s, -18d 05m 27s. All the CDS lists near this position are some 'Radio Sources'.

See this marked image for identifications.

These descriptions from the on-line Edward Emerson Barnard "A Photographic Atlas of Selected Regions of The Milky Way":

92
α(2000)18h 15m 35s, δ(2000) -18 14
Galactic Coordinates 13, -1
 Black spot, 15 N and S, 9 E and W. This black spot, known to me in my early days of comet seeking, is very sharply defined on its east edge but less definite on the west. There is a twelfth-magnitude star near the middle with several other small stars (see ibid., 38, 496, 1913, Plate XX, for an account of this remarkable object).
93
α(2000)18h 16m 54s, δ(2000) -18 04
Galactic Coordinates 13, -1
 Cometary, a sharply defined black head 2 in diam., with a diffused tail 15 long running S, 20 NE of B 92