M 18 (NGC 6613, Lund 826) Open Cluster in Sagittarius

Located at: RA 18 hours 20 minutes 00 seconds, Dec -17 degrees 06 minutes 00 seconds

Size: 9.0' (7.0') Magnitude: 6.9 Class: II 3 p n

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 Deep Sky filter, 150 minutes (15 x 10 minute subs), 09/13/2007

Processing:

CCDStack 1.3, Photoshop 7.0

Location:

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

Notes: According to "Star Clusters", by Brent Archinal and Steven Hynes, the size of this open cluster is 7.0 arc minutes.

From the NGC / IC Project:

Contemporary Visual Observation(s) for NGC 6613

NGC 6613 = M18
18 19 58.5 -17 06 07
V = 6.9;  Size 9

17.5": at 100x, bright, scattered, includes three mag 9 stars and 10 mag 11 
stars.  The bright stars form a "V" asterism with the vertex to the NNE.  
Includes a few wide double stars.  At 220x, 40 stars are visible in a 7' 
diameter, scattered but distinctive.  The bright group of 15 stars forming the 
"V" asterism are surrounded by a dark circular void.  The rest of the cluster is 
to the S and W of the "V".  Only a few faint stars are involved and the cluster 
appears fully resolved.

- by Steve Gottlieb