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Astrophotography by Bob Franke

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NGC 6709 - Open Cluster

 

Click the image for a 67% size wide field view. (2925 x 1646 - 2.46 MB)

Instrument

12.5" RCOS @ ~ f/9 (2880 mm fl) at 0.64 arcsec/pixel. Shown at  0.85 and 2.0 arcsec/pixel.

Mount

Paramount ME

Camera

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

Acquisition Data

10/2/2017 to 10/6/2017 Chino Valley, AZ. with CCD Commander & TheSkyX.  AOL guided

Exposure

RGB

 300 min (20 x 5 min. each) Bin 1x1

Software & Processing Notes

 

  • CCDStack, PixInsight, Photoshop CS6.

  • eXcalibrator v6.2 for (g:r),(b:r) color balancing, using 1,685 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

Comment

 

The cluster is shown rotated 160 counter clockwise.

NGC 6709 is an open cluster in the constellation Aquila at a distance of about 3,500 light-years. The cluster has about 60 stars and is about 315 million years old. The many slightly blue stars are are evidence of the cluster's relatively young age. By comparison, our cooler more yellow Sun is about 4.5 billion years old.