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How Good Are ED-APO Telescopes for Imaging?

Aug 16 2020 10:08 AM | tom_fowler in Articles

I decided to compare three telescopes to determine how they image two stars: Vega (type A0) and Albireo (types K3 and B9). Albireo turns out to be the difficult test because of the color contrast of its two components. The fainter component, Albireo B, is coincidentally a B-type star, which accounts for its readily observed blue color. The brighter star, Albireo A, is a K type star, with a yellowish-orange color typical of such cooler stars. Vega, as a type A star, is not as hot and not as blue as Albireo B. This turned out to be apparent in course of the tests that I did.

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Intergalactic Supernovae

Jul 11 2020 11:04 AM | JoeR in Articles

Whether with an eyepiece or a camera, observing intergalactic supernovae connects you to the awesome power of creation from destruction. When we observe a supernova we are witnessing the final moment in the life story of massive star and a cataclysmic event beyond all human experience- one that makes its fury known across half the Universe. Yet, we are also seeing the unmistakable hints of our own origins. Life as we know it could not exist without the elements forged in the nuclear furnace of a high mass star long ago. That star ripped itself to shreds in a violent death so it could deliver the building blocks of life when our solar system was born.

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Color-correcting a flat panel

Jul 11 2020 10:57 AM | Michael Covington in Articles

It all started with a red galaxy. I took a picture of M61 with my DSLR and calibrated it with PixInsight. It puzzled me that the corrected, calibrated image came out strongly red...

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BASIC EXTRAGALACTIC ASTRONOMY - Part 6: Galaxies, Discovery and Classification

Jul 11 2020 10:48 AM | rekokich in Articles

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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Some Useability Improvements for Celestron 8” EdgeHD and Similar Telescopes

Jun 22 2020 10:16 AM | tom_fowler in Articles

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

Jun 22 2020 09:40 AM | LB Myers in Articles

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

Jun 22 2020 07:43 AM | Aworonow in Articles

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

May 12 2020 04:05 PM | the Elf in Articles

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

May 09 2020 02:26 PM | JoeR in Articles

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

May 09 2020 01:56 PM | LB Myers in Articles

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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