Articles

The Discoveries of Galileo – Part 3: The Moon

In the fall of 1609 Galileo began studying the Moon with his spyglass and he would sketch the features he saw. We need to understand that the magnification of his spyglass by this time was around 21x and it had a very narrow field of view such that he could only see about half the width of the Moon. His telescope was also rather long at about a meter (39.4”) so it must have been very difficult for Galileo to track the Moon with his makeshift tripod.

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The Discoveries of Galileo – Part 2: Sunspots and Their Movements

Last month I wrote in Part 1 about Galileo’s discovery that the wandering star, Jupiter, was a planet that had four moons. Recall that my motivation was reading the book Discoveries and Opinions of Galileo published in 1957 by Stillman Drake, a Canadian historian and authority on the complete works on Galileo. This article will cover Galileo’s observations of sunspots which got him into hot water with the Roman Catholic Church in 1616.

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WarpTune my Advanced VX?

This question eventually surfaces on just about every mount found in the low to medium range. If you pay $6,000 for a mount it has probably been tuned during manufacturing. For a mount like the AVX what you get is an assembled piece of machinery that is simply bolted, snapped, or screwed together and never really tested or adjusted for fine operation. That is why your mount is usually stiff or tight. I recently bought a new Advanced VX mount as a part of my down-sizing program.

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Beginner's Astrophotography: Can I use my unmodified DSLR?

It is often recommended to modify DSLR's for deep sky photography. It may be one of the first topics a beginner comes across and sometimes the recommendation sounds like modding is an absolute necessity. There are good reasons not to do it, for example the camera is used for daytime photography as well or the budget does not allow either to have an existing camera modified or get a modified one. I don't want to go deeper into it. I'm also not opposed to modified cameras. I just would like to show what can be done with an unmodded relatively low priced DSLR if modding is not an option.

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The Discoveries of Galileo – Part 1: Jupiter

We amateur astronomers should all be familiar with who Galileo di Vincenzo Bonaulti de Galilei aka Galileo Galilei (1564-1642) was. He has been called the father of observational astronomy.

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A Backyard Observatory For Under $500?

Back in my days as a Quality/Reliability Engineer, we had a motto by which we lived; “Good, cheap, easy……Pick any two”. For this project I chose cheap and easy. I would keep my computer, cameras, and accessories in my den when not in use, and the mount and telescope could stay, semi-permanently situated outside. The search began. Who in the world makes a portable or temporary structure large enough to provide security for a 10” f/4 newtonian riding on a Celestron CGX mount?

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Musings over Mars

Braved the first frosty forecast of the season Tuesday evening GMT for a couple of hours at the eyepiece under clear South London skies to have a go at sketching the Red Planet before the distance becomes too great.

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Photoelectric Photometry of Variable Stars - Past and Present

Someone on the Classic Telescopes forum asked me (see reply #3750) to share what I called "another story" of my experience with photoelectric photometry (PEP) of variable stars. I hope this article will encourage others to make such contributions to scientific studies of variable stars. So what follows will largely be what I remember about my experience as a photoelectric photometrist back 1985-90. Many of the concepts and techniques are still valid today. You'll find technology has improved greatly since 1990.

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A Word About Eyepieces

I can only conclude that prospective buyers can get a good set of eyepieces at great savings. Statements about cheap low quality eyepieces made in China are not necessarily true! And remember that just about anybody’s eyepieces come from China these days! Finally, in this COVID era, there is more good news -- a beginning ATM or amateur astronomer with limited resources can get this eyepiece set and begin his hobby better equipped than he would think. I think it is better to have a set of eyepieces than a single high-priced eyepiece. Isn’t having only one magnification a little boring?

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BASIC EXTRAGALACTIC ASTRONOMY - Part 7: Galaxies - Morphological Diversity

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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