Sunday, February 7, 2021


Finding binary stars has been fun and rewarding on several levels. First is the satisfaction from perceiving something that is not obvious to animal sensations. A modest telescope reveals that very many stars which appear as one are actually pairs and systems. Finding them required getting more familiar with the night sky and learning is fun. And there was discovery: even though someone else had found it first, the insight and understanding were my own. 


Binaries and systems are the rule, not the exception. The stars are not randomly scattered individuals—though those do exist, even wandering rogues—but aggregations that are bound by internal and external gravity, and other forces and fields. 


Epsilon Lyrae is a famous double-double.
I was encouraged to pursue it by friends online
at TheSkySearchers dot com.

In the 200 years after Galileo, telescopes opened the heavens to exploration. Wanting to measure the distances to the stars, astronomers sought certain pairs, a very bright one and a much dimmer one. The assumption was that stars are randomly distributed. So, if two neighboring lights were different in apparent magnitude, the brighter one was much nearer, and therefore measurable with the instruments of the time. It was the search for parallax. After cataloguing thousands of stars and hundreds of binaries with one of the largest telescopes, while parallax measurements remained beyond our grasp, William Herschel came to understand that binaries are a natural phenomenon, not visual accidents. 


Polaris (left) and Alcor-Mizar (right)
in Meade 10-inch catadioptric on loan from 
the Austin Astronomical Society.

Following William Thompson’s mandate,  I want to measure what I observe. In another topic I mentioned having been loaned a Baader Micro-Guide reticle. But even before that, I figured out that I could keep both eyes open and use a simple ruler to help me scale my sketches. I can calculate the field-of-view, and with a compass and graph paper, set a circle into which I can draw my observations.


One night, while aligning on Mars,  I happened upon the binary Eta Piscium. At that point, I had followed instructions to locate five or six such objects, including the “Double-Double” in Lyra. When I saw them, they just looked like a binary. So, I noted the time and approximate location and looked them up later. 

My last investigation (03 February) was Castor in Gemini, an easy double, and revealed in the largest telescopes to be a system of six.


I learned of Zuben Elgenubi from a Hayden Planetarium
show in July 1969. Looking it up online, I found that it is
an easy double and a complex system.

All of that let me retrace the steps of the first pioneers in astronomy. On the one hand, I know from my own university education and from judging regional science fairs for over a decade, that we do not reward scientists for repeating and testing the works of others. We prize originality so much that perhaps one-half to three-fourths of all published papers are never independently validated, all the moreso in physics (and astronomy), less so in chemistry and sociology which are practical pursuits. So, I like knowing that the universe is pretty much as described. On the other hand, revisiting the discoveries in astronomy is analogous to the small wonder of holding an ancient coin and understanding it as a window into the cultural context of their time and place. 



Measuring Your Universe: Alan Hirshfeld’s Activity Manual

Base 7 

Turing’s Cathedral 

Numismatics: History as Market 

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