Articles

Some Useability Improvements for Celestron 8” EdgeHD and Similar Telescopes

Everyone who has worked with the Celestron 8” EdgeHD telescope, and I’m sure other 8” SCTs, knows their useability problems: (1) the scope is difficult to focus, and (2) the screw-on diagonal provided by Celestron is difficult to tighten enough to prevent eyepiece rotation, and when it is tight enough, very difficult to loosen. I worked on these problems for some time, and have come up with what I believe are very worthwhile improvements.

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A NO-NAME TELESCOPE

Back in 2002, a friend gave me an old 8” Criterion Newtonian, circa 1963, as a wedding gift. It was in a questionable, but useable state. I set it up a few times but for the most part, it sat in storage. I did discover back then that it had an old Cave mirror and not the original Criterion mirror. When collimated, the images were outstanding. Fast forward 15 years and plus one son. I decided that I would fix up the old Criterion for his 10th birthday.

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SubframeSelector Weighting Tool (SWT), v 1.0.0

This document describes a user-friendly spreadsheet designed to assist in the comprehensive, methodical assignment of relative weights to subframes. The tool, named the “SubframeSelector Weighting Tool” (SWT), interacts with PixInsight’s SubframeSelector script, serving both as the source of its inputs and as the recipient of its weighting-equation output. We explain the rationale for the approach implemented within SWT and the procedural steps required to generate its weighting-equation output.

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Low Cost Deep Sky Astrophotography

Now that my 50th birthday is near I am able to buy what in my eyes is a decent astro photography rig. Many CNers are in the same shoes now as I was then, especially in the current COVID crisis when salary is reduced or people even lose their jobs. Having plenty of time it is, of course, the right thing to do something and not just hang around. Being thrilled about a topic obviously causes people to accept a lot of compromises. In this article I would like to show possible ways to get into this hobby even with a very low budget. More importantly I would like to show what limitations come with low priced equipment and hopefully save someone from great disappointment when the first image is processed.

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30 years into the Void: A History of the Hubble Space Telescope

On August 24, 1990 the Space Shuttle Discovery embarked on mission STS-31 which deployed a very special payload into orbit: a $1.5 billion Ritchey–Chrétien astrograph known as the Hubble Space Telescope (HST). It was equipped with a 2.4m primary mirror and 57600mm of focal length. HST was the first of its kind, a visual light reflector telescope operating outside of the Earth’s atmosphere giving it a clear, undistorted view of the Universe.

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CLEANING UP A CAVE ASTROLA

All in all, the project took about a year and a half. There were times when I wondered if I would ever finish it. The optics turned out to be better than expected. Views of the planets and moon are just what you would expect from a classic Cave 10” F-6. When I have taken it to a dark sky location the deep space views were fabulous. It was a very worthwhile project.

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I NEED A LARGER LIVING ROOM!

“Our largest and best…the 8” reflector. Designed for serious amateurs, colleges, schools”. Or, “The Super Space Conqueror…6” reflector telescope. American made”. My dreams were fed by those Edmund ads. What a dilemma for a 14-year-old back in the mid-sixties.

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BASIC EXTRAGALACTIC ASTRONOMY - Part 5: Black Holes and Quasars

The only primary evidence available to an astronomer about a very remote object consists of photometric measurements, a spectrogram, and an image which is in many cases no more than a pinpoint of light. In this article we present basic cosmological concepts and simplified mathematical methods which allow an amateur to derive from this meager data a surprising number of physical properties of distant extragalactic objects with a precision of several percent within professional results.

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A Look at the Future of Amateur Telescope Makers

Telescope making in particular is one of the facets of amateur astronomy that for so long has begun to drastically shrink in size and to perhaps seem due to disappear entirely. After all, with the availability of the omnipresent Chinese-made telescopes that have all but cornered today’s market, there’s little economic incentive to build your own scope - even at the largest apertures like 20 inches, mass manufacturing has begun to eat away at the surface-level basic cost advantages in doing it yourself.

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BASIC EXTRAGALACTIC ASTRONOMY - Part 4: Luminosity Distance, Cosmic Dimensions, Cosmic Magnification

The only primary evidence available to an astronomer about a very remote object consists of photometric measurements, a spectrogram, and an image which is in many cases no more than a pinpoint of light. In this article we present basic cosmological concepts and simplified mathematical methods which allow an amateur to derive from this meager data a surprising number of physical properties of distant extragalactic objects with a precision of several percent within professional results.

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