Pencil sketch using a 10-inch Newtonian reflector @ 190x.  Roger Ivester

Pencil sketch:  Inverted color 

Observer’s Challenge Link:

OCTOBER 2015 OBSERVERS CHALLENGE – NGC-7128

NGC 7128 – Open Cluster in Cygnus –  
Date: October 2015
Conditions: Very Good
NELM: 5.2
Telescope: 10-Inch Newtonian reflector
Eyepiece: 12 mm + 2x Barlow
Magnification: 190x
FOV: 0.32º – 19 arc minutes

Easy to locate and see at low magnification, appearing as a small concentrated round hazy spot, with several bright stars on the outer edges. When increasing the magnification to 190x about 13 stars could be counted encircling a hazy central region of fainter stars. At the higher magnification the cluster became octagonal in shape. I could count three pair of doubles in the outer ring. The brightest star is magnitude 11 on the SSE tip. The cluster was much smaller than I remembered when I observed it last on 9-27-93, using the same telescope and from the same site.

The late North Carolina amateur, Tom Lorenzin said: “small compressed and memorable! brighter members make a small pentagon.”    Roger Ivester

The following pencil sketch was made by Jaakko Saloranto of Finland, using a 4.5-inch Newtonian reflector @ 261x with a NELM of around 6.0. 

“Small 2.5′ cluster of ~10 stars magnitudes 11-13. Easily visible @ 38x (66′) as a small glow NW of 10th magnitude star. Sky conditions and weather: 20°F, humidity 84%, Aurora Borealis in the northern sky. SQM-L reading 20.05 aimed at the object with naked eye limiting magnitude around 6.0.”  

The following image was made by Dr. James Dire from Hawaii, using a 10-inch F/6 Newtonian Reflector and a SBIC ST-2000XCM CCD Camera.  Exposure 30 minutes… 

This entry was posted on October 24, 2015 at 2:02 pm and is filed under Work File Only - Observer's Challenge Reports. You can subscribe via RSS 2.0 feed to this post's comments. Both comments and pings are currently closed.