Focal Pointe Observatory
Astrophotography by Bob Franke

Home
Recent Images
Galaxies
Nebulae
   Natural Color
   Narrow Band
   H-Alpha
Clusters
Comets
Solar System
Observatory
Equipment
My Freeware
Tips & Tricks
Published Images
Local Weather
Terrestrial

 

Send Email

 

 

 

 

 

 

 

 

 

 

NGC 7209 - Cluster

5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Click the image for ~ 75% size view. (2979 x 1676 - 1.37 MB)

Instrument

12.5" RCOS @ ~ f/9 (2880 mm fl) at 0.64 arcsec/pixel. Shown at  0.85 & 2.78 arcsec/pixel.

Mount

Paramount ME

Camera

SBIG STL-11000 w/ FW8 filter wheel & AstroDon Gen-2 RGB filters.

Acquisition Data

9/24/2020 & 9/25/2020 Chino Valley, AZ. with CCD Commander & TheSkyX.  AOL guided

Exposure

RGB

240 min (16 x 5 min. each) Bin 1x1

eXcalibrator RGB ratios are 1.00, 1.05 & 1.20

Software & Processing Notes

 

  • TheSkyX, CCDStack, PixInsight, Photoshop CS6 and Noiseware 5.

  • eXcalibrator v6.2 for (g:r),(b:r) color balancing, using 1,515 stars from the Pan-STARRS database.

  • CCDBand-Aid to repair KAI-11000M vertical bars.

  • CCDStack to calibrate the sub exposures.

  • PixInsight processing includes CosmeticCorrection, data  rejection, mean combine the sub-exposures, create the RGB image, gradient removal and non-linear stretching with HistogramTransformation.

  • PhotoShop for additional background neutralization and background smoothing.

Comment

 

Shown rotated 95 clockwise.

Discovered by William Herschel in 1787, NGC 7209 is an open cluster in the constellation Lacerta. The cluster is about 3,810 light years away and is "only" about 410 million years old. The presence of many bright bluish stars supports the relatively young age estimate.