NGC 6756 (Cr 398, Lund 879) Open Cluster in Aquila

Located at: RA 19 hours 08 minutes 43 seconds, Dec +04 degrees 42 minutes 19 seconds

Size: 4.0' Magnitude: 10.6 Class: I 1 m

North is up

West to the right

Telescope:

 14.5" f5 Newtonian reflector

Camera:

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

Image:

Lumicon Red filter, 410 minutes (41 x 10 minute subs), 09/8/11/12/2017; seeing 2.8-4.9 FWHM per CCDStack

Processing: CCDStack 2.94.6355.18107, Photoshop CS5.1
Location:

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

Notes:

Moved back to the southern skies as the moon rises later in the east ...

From the NGC / IC Project:

NGC 6756 = Cr 398 = Lund 879 = OCL-99

19 08 42 +04 42 18

Size 4'

17.5" (7/27/92): at 280x, about two dozen mag 11.5 and fainter stars in a 6'x4' field surrounding a bright knot just east of center.  A mag 13 star is at the NE edge of the knot.  With concentration the central knot resolves into half a dozen very tightly packed mag 14 stars.  The brightest mag 11.5 star in the cluster is 3' S of this knot.  Set over unresolved background haze.  Located 30' NE of open cluster NGC 6755.

8" (8/28/81): few faint stars at 100x over background haze.

WH discovered NGC 6756 = H VII-62 = h2031 on 21 Aug 1791 (sweep 1017) and recorded "a small pretty compressed cl. of stars, not very rich."  JH made a total of 4 observations.  On 13 Aug 1830 (sweep 278), he called it "pretty rich; S; m compressed; oval or rather fan-shaped.  The stars 11...12m, 4' in extent; the nf side most compressed."