Articles

BASIC EXTRAGALACTIC ASTRONOMY - Part 3: Luminosity Corrections, Cosmological Extinction, and Mas...

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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BASIC EXTRAGALACTIC ASTRONOMY - Part 2: Distance, Luminosity, and the Hubble Parameter

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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BASIC EXTRAGALACTIC ASTRONOMY - Part 1: Redshift and Recession Velocity

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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York County Star Party

The York County Star Party exceeded my expectations – by about 1,000%! I don’t normally post online, but I let Phil know I would be speaking out about this. More astronomers need to know about this event. It is located conveniently close to home for many in the Baltimore-DC-Philly megaplex and it’s a “Winner.” I hope to see more of you there next year.

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New approach for Polar Alignment

The topic of Polar Alignment is not at all new. Lot of approaches, automation tools are available. Yet, some aspects in all the current approaches drove me towards doing some more work. The key aspects of this approach are as follows. - Ability to do the Polar alignment without polaris sited - Relatively less complexity than drift alignment - Ability to address to a good extent the atmospheric refraction to finally locate correct NCP / SCP position - A good starting point for amateurs who wish to graduate towards sophisticated tools and techniques - Ability to quickly verify if the polar alignment is intact after one object photographed or viewed, and the equipment is being pointed to another object. This point is mentioned in light of the fact that sometimes the polar alignment gets disturbed and the next object photographed shows star trails. This is especially true if payload is tweaked for next photo.

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My Other Telescope is an 8.4 Meter - Part III: Polishing

I've started writing about this aspect of fabricating the world's largest monolithic mirrors a number of times. Each time I get to about ten pages before I realize how truly complex this phase of fabrication is. So, I am going to assume, for the sake of this account, that everything works as planned and there are no side tracks. That won't be true, but if I tell the real story, I'll never get done.

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Filter Comparison For Imaging Broad Spectrum Objects In Light Pollution Areas

The primary purpose of imaging with a filter in the city is to mitigate light pollution and help suppress the noise so that the signal of the target object becomes easier to identify. This is rather easily achieved for nebula type objects that emit at very specific wavelengths but much more challenging to accomplish for full-spectrum sources such as galaxies and globular clusters. Cutting down on city glare is becoming even more challenging as city lighting transitions from Mercury type lighting that emits at defined wavelengths to LED lighting that generally emits broad spectrum lighting.

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My Other Telescope is an 8.4 Meter: Part II - Casting

How do you create the world's largest monolithic optical mirror? As the saying goes, “One bite at a time.” It is a unique process in that it is entirely linear. No aspect of the process can be done in parallel since each step is entirely dependent upon the preceding step.

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My Other Telescope is an 8.4 Meter

Upon my retirement from the Army I did the typical Law Enforcement track. It only took a year with the Sheriff's Department to realize that I just didn't want to carry a gun anymore. While looking around for a challenging alternative I ran across an ad for a “Mechanition” (Read Gofor) at the Steward Observatory Mirror Lab. I was intrigued and applied for the position.

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A Bigger, Better Scope Anyone Can Build & Use

Sometimes life’s greatest treasures are the unexpected. That’s how I feel writing this article. It was relatively recently that I embarked on building my 20”, and it’s been only six months since I penned the article on my 16”. Since that article, I’ve grown not only as an ATM, but also as a person and as a writer. I thought I’d share that growth here. ‘Tis the season of giving, after all!

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