Astronomical Society

About the Longmont Astronomical Society

The Longmont Astronomical Society is a non-profit amateur astronomy club based in Longmont, Colorado. The club was founded in 1987 by people enthused about astronomy and who were looking for an avenue to share their enthusiasm with others of like interest. Since then the club's membership has grown to over 100 (both families and individuals) that embody all levels of experience and interest.  All of the photos at right were taken by members of the club.

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Membership in the L.A.S. is open to all people of any age.  We offer Student and Individual Memberships.

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Click to see photos...     May Owl Hollow Excursion     

Next LAS Meeting: Thursday, November 21, 7:00 PM

Building and Using an Astronomical Spectrometer

Spectrographs are an essential tool in astronomy, and are  found most often in the capable hands of the scientists studying a wide range of phenomena. But did you know that the amateur astronomical community also employs these instruments in the pursuit of expanding our understanding of the cosmos?

Our own LAS member Clarke Yeager will share his experience building and using a spectrograph at the November LAS meeting. Clarke constructed his instrument using his 3D printer, and then tested and recorded the spectrum of many of the filters used for imaging, as well as various light sources found in our daily lives.

Here's a note from Clarke...

I have been interested in photography, science, and astronomy my entire life. I met a friend a couple of years ago at the solar eclipse who got me interested in doing astrophotography. I joined LAS to learn more about astrophotography. At my first meeting I met Wayne Green who suggested I come to BASS in Boulder. That group is more interested in the science of astronomy rather than just astrophotography. Both of these met my interests.

I started doing some astrophotography in my backyard here in Longmont using my canon 6D Mark II camera with a 400mm lens, but was dealing with so much light pollution that it was hard to get satisfactory results. When I bought my telescope, the salesman suggested an IDAS LPS-D2 light pollution filter based on how I described my location. This filter didn’t work well for my conditions. Some further research pointed to the LPS filter, which I purchased; it worked much better.

Wayne connected me with a group that was using a 3D printer to make a spectrometer. When I completed building it, I decided to look at the light pollution filters that I had purchased and see why one worked better than the other. Since then several of my friends were kind enough to loan me some filters to see what their spectral characteristics are and how that affects light pollution. In addition to my filters I have looked at narrow band filters, LRGB filter, some specialty filters like the L-eNhance filter, and even some visual filters.

I have shown some of my preliminary results to several of the LAS members and they thought other members of LAS would be interested in seeing my study and asked if I would be willing to give a presentation.

Copyright (c) Longmont Astronomical Society 2019. All rights reserved.
The Longmont Astronomical Society is a 501(c)3 non-profit organization. P.O.Box 806, Longmont, CO 80502-0806, USA

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