2021 Michael A. Siniscalchi

What's New



Odds n Ends

     IC 4756     
      Open Cluster in Serpens
      RA:18h 36m 14s  Dec: +04 46' 20" Distance - ~1300 ly 

Click on image for larger size
Location & Date
Backyard, Abbott Observatory- Long Island, NY,  July-August 2021
Orion ED80 F/7 APO, Moonlite focuser, iOptron GEM45G, Pegasus Falcon rotator
Image scale 2.54 arcsec/pixel
Baader R G B  filters
CCD temp -10C
Red - 6x10m  Green - 6x10m  Blue - 6x10m  Bin 1x1  for each of the 4 panels
Planning & Acquisition
Image planning - Sequence Generator Pro Mosaic tool
Image acquisition - Sequence Generator Pro w/PinPoint & PHD2 (guiding))
Astro Pixel Processing -  Calibration, Normalize, Alignment,  Mosaic stitching, RGB combine
Adobe CS4 -  Color Image  adjustments, Noise reduction, JPEG conversion

This is a 4 panel RGB mosaic.

From Wikipedia;
IC 4756 is a large bright open cluster in the constellation Serpens. Known as Graff's Cluster, it is bright enough to be seen with the naked eye and considered a fine cluster for binoculars or small telescopes.

IC 4756 is also known as the Tweedledee Cluster (when paired with NGC 6633 as Tweedledum), also as the Secret Garden Cluster.

This target was used as a test of the new iOptron GEM45G mounts ability to position accurately for mosaic panels, which it has performed excellent.