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CN Reports
How to add a counterweight to a Unitron AZ 114 or 140 mount
Mar 01 2024 07:00 AM |
bmwscopeguy
in CN Reports
With this easy addition, the scope is now ‘almost’ in balance through most of its motion, and the springs have an easier time returning the scope to the horizontal position. And the best thing is that it requires no alteration of the mount and is fully and easily reversible if you choose.
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Viewing the Southern Skies at OzSky Star Safari
Aug 01 2023 05:00 AM |
rjacks
in CN Reports
OzSky provides a fabulous fall (March or April) astronomy camp under dark clear skies in an idyllic setting with gracious and personable hosts, daytime lectures, photography seminars, opportunities for great hiking and birding, and a convenient and comfortable place to stay. One of the hosts is a well-known source of good advice on CN. The enthusiasm among all the participants was infectious.
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The Astronomer at the Museum: Miss Expanding Universe
May 09 2020 11:33 AM |
Larry F
in CN Reports
The Art Institute of Chicago is a museum that I have always considered to be one of the best in the world, even though I’m a New Yorker and a member of the Metropolitan Museum of Art. As my wife and I were ambling through one of the American galleries on a visit in 2018, we looked up to see a figure hanging from the ceiling. It was Isamu Noguchi’s 1932 aluminum sculpture Miss Expanding Universe. We are great fans of this artist for his vast and brilliant output that includes such diverse works as portrait sculptures, furniture (we have a Noguchi-designed coffee table our living room), fountains, monumental abstract sculptures and vast garden installations.
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The Astronomer at the Museum: Max Ernst and Wilhelm Tempel
Apr 01 2020 07:51 AM |
Larry F
in CN Reports
One of the great things about astronomy is how it connects you to so many spheres of human thought and activity, both scientific and cultural. You never know when some unknown link is suddenly revealed, and you learn something remarkable. My latest “astrocultural” discovery was at the Museum of Modern Art, which in the fall of 2017 exhibited a large selection of its extensive holdings of works by the prolific German surrealist artist Max Ernst (1891-1976).
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Deep Sky Lucky Imaging
Jan 14 2020 01:53 PM |
CygnusBob
in CN Reports
Amateur astronomers have been using lucky imaging for planetary targets with great success. The basic strategy is to obtain a large number of short exposure images in order to “freeze” the turbulence and then select the sharpest images for alignment and integration. Short exposures are valuable because the biggest effect of turbulence for small telescopes is image jitter. For long exposures, the image jitter gets averaged out, just generating a blurred image. The problem with doing this with deep sky objects is that the number of photons collected in a 1/60 of a second is rather small in most cases. This makes it hard to determine an image shift accurately. However lucky imaging can still help sharpen DSO imagery.
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Optimal Filtering for Deep Sky Lucky Imaging
Dec 15 2019 12:30 PM |
CygnusBob
in CN Reports
A paper that describes a method of noise reduction for DSO imagery that I have invented for Deep Sky Lucky Imaging. I am Dr. Robert Majewski, a retired engineer living in Las Vegas. I have M.S. and Ph.D. degrees in Physics from the University of Illinois. My career involved testing and calibrating a number of imaging electro-optical systems at the Hughes Aircraft Company and Raytheon Missile Systems. My hobbies include high resolution planetary imaging, exo-planet transits and deep sky imaging.
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Observer's Handbook - 2019 Updated Preview
Sep 23 2018 11:14 AM |
Tom T
in CN Reports
Tom Trusock and Denise Moser takes a look at the upcoming 2019 edition of the RASC Observer's Handbook.
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Observer's Handbook 2016
Dec 15 2015 09:39 PM |
Tom T
in CN Reports
Tom Trusock takes a look at the 2016 edition of the RASC Observer's Handbook.
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observing
Thermal Modeling and Athermalization in Telescope Optical Design
Dec 09 2014 03:16 PM |
Mike I. Jones
in Technical Reports
Telescopes are typically stored and operated over a wide range of temperatures. Changing temperatures and extreme temperature ranges affect nearly all materials used in constructing telescopes, as well as the optical properties of the air in the immediate vicinity. This article discusses the two principle effects of temperature on telescope materials: (1) changes in optical and structural material dimensions with temperature, and (2) changes in optical glass refractive index with temperature. These two temperature-dependent material properties usually combine to negatively affect optical performance in refractive and catadioptric systems if not compensated for, and system optimization must account for these properties in the design phase to minimize temperature effects on telescope performance.
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A. Jaegers Optical Corporation--A personal recollection
Nov 22 2014 02:37 PM |
Scott in NC
in Other Reports
A. Jaegers Optical Corporation--A personal recollection Stephen L. Nightingale For many teenagers in the 1960’s, an after-school or summer job meant...MacDonald’s! As a teenage amateur astronomer and telescope nut, I had the perfect job--working for Al Jaegers at A. Jaegers Optical Corporation from 1968 to 1970.
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