Archive for May 23, 2010

A 4-Inch (102mm) Refractor Can Be An Excellent Deep-Sky Telescope: Finally Sirius B, Barnard’s Galaxy, and Much More….

May 23, 2010

All Observer’s Challenge Reports to-date:

https://rogerivester.com/category/observers-challenge-reports-complete/

      Walter Scott Houston, most often used a 4-inch Clark refractor for his observations of deep-sky objects while writing the monthly “Deep-Sky Wonder’s” column in “Sky & Telescope Magazine” for 46 years until his death in December, 1993.  

     When Sue French picked up DSW’s, she seemed to favor the use of a 105mm refractor for many observations over her twenty years writing the column.  

      I purchased my 102mm f/9.8 refractor in 1997, and have enjoyed using this scope over the years.  It provides for a nice velvety black background with excellent contrast of faint deep-sky objects within its reach.  

      On nights of good seeing, it will easily exceed Dawes Limit:  https://www.astronomics.com/info-library/astronomical-terms/dawes-limit/  

      Double and multiple stars have always been of interest to me, and I’ve observed hundreds of close double and multiple stars over the years with this telescope.  

photo   

The value of a correct image diagonal:

I’m now using a correct image 90º diagonal.  The view through a standard 90º diagonal, whether using a refractor, Schmidt-Cassegrain or Maksutov-Cassegrain makes it impossible (at least for me) to sketch a deep-sky object, scientifically correct. I like to make my sketches as they are truly oriented in the sky, with north at the top and west to the right on my sketch card.  

https://www.telescope.com/The-Advantages-of-Observing-with-Correct-Image-Diagonal/p/106656.uts

 

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NGC 4889 and NGC 4874 – Galaxies in Coma Berenices – 10-inch reflector @ 143x

May 23, 2010

Faint galaxies in Coma

NGC 4889 and NGC 4874 10-inch reflector @ 143x

NGC 3190 – Galaxy Cluster – 10-inch Reflector at 114x – FOV 1/2º

May 23, 2010

NGC 3190 Galaxy Cluster - 10-inch Reflector @ 114x

NGC 3190 compact galaxy cluster; Leo