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National Capital Astronomers

About NCA

NCA logoServing science and society since 1937. The National Capital Astronomers (NCA) is a non-profit, membership supported, volunteer run, public service corporation dedicated to advancing space technology, astronomy, and related sciences through information, participation, and inspiration, via research, lectures and presentations, publications, expeditions, tours, public interpretation, and education. NCA is the astronomy affiliate of the Washington Academy of Sciences. We are also members of the Astronomical League, in fact NCA members helped form the Astronomical League a long time ago.

NCA has for many years published a monthly newsletter called Star Dust that is available for members. Besides announcement of coming NCA meetings and a calendar of monthly events Star Dust contains reviews of past meeting and articles on current astronomical events.

NCA is a very unusual astronomy organization. All are welcome to join. Everyone who looks up to the sky with wonder is an astronomer and welcomed by NCA. You do not have to own a telescope, but if you do own one that is fine, too. You do not have to be deeply knowledgeable in astronomy , but if you are knowledgeable in astronomy that is fine, too. You do not have to have a degree, but if you do that is fine, too. WE ARE THE MOST DIVERSE local ASTRONOMY CLUB anywhere. Come to our meetings and you will find this out. WE REALLY MEAN THIS!

Our Meetings

Monthly Meetings with Educational Presentations are Free and Open to the Public

NCA has regular monthly meetings September through June on the second Saturday of the month.

Public transportation: Directions/maps to the UM Observatory
Inclement weather: In case of severe weather (tornado/snow/impassable roads), a notice will be placed on the Observatory Website on the day of the meeting. (Be sure to refresh/reload the page to make sure you are seeing an updated page.)

Meeting Schedule for 2011 - 2012

Most meetings will be held at the University of Maryland Astronomical Observatory in College Park, Maryland.

Next Meeting Date: Saturday, Jan 14, 2012

7:30 pm at the University of Maryland Observatory on Metzerott Road.

Amateur Telescope Making - A Talk and Demonstration

Speaker: Guy Brandenburg

Abstract: Making your own telescope provides great satisfaction, as well as the the pleasure of learning and using a wide variety of applied and theoretical sciences. In addition, the makers and users of amateur telescopes continue to make significant contributions to astronomy.

But the hobby of amateur telescope making is in transition. As more people are becoming interested in amateur astronomy, and can afford to spend money on equipment, the real prices for Chinese mass-produced telescopes and other gear seem to be coming down, while quality has improved, and apertures are much larger than they were in the 1950's or 1960's. That is affecting decisions on whether to buy a telescope or build it. Pushing in the same direction, the price for Pyrex or equivalent mirror blanks has approximately tripled in the past year, and prices for this glass do not appear to be going down any time soon.

Thus it is now less important than it used to be to try to save money by making your own optics. Amateur telescope making clubs are much smaller than they were half a century ago.

Amateur telescope makers of the future may spend a smaller fraction of their time on making the optics of a new telescope than on new and perhaps hitherto unknown methods of telescope control and image capture, and on perfecting other aspects of their own telescope or observing process.

Bio: Guy Brandenburg has a French baccalauréat in mathématiques élémentaires, a BA in history from Dartmouth College and a master's degree in secondary math education from University of Maryland at College Park. He is now happily retired after over 30 years of teaching secondary mathematics in the DC public schools, and coaching various successful math and soccer teams.

Like most makers of amateur telescopes, he acquired his telescope-making skills on his own initiative. He sought out hands-on training by other amateur telescope makers, and observed their techniques. He also experimented and read extensively.

While growing up from 1952-1961 on a mixed-use farm in Clarksburg, MD, Guy learned how to use simple tools. He later followed his older brothers in their hobby of manufacturing fireworks for the family 4th of July displays. He tried (without much success) to build a number of devices from C.L.Stong's 1961 book that collected a wide variety of projects from previous Amateur Scientist columns in Scientific American magazine. (He looked wistfully at the articles on home-made atom-smashers, Van de Graaf machines, and X-ray machines....)

It was only much later that he felt he might be able to afford to build a telescope. The direct impetus was hands-on experience he gained in the late 1980s from doing a kitchen renovation, and inspiration from Richard Berry's book on how to make a telescope.

He made his first telescope mirror, a 6" f/8, under the guidance of Jerome (Jerry) Schnall, in 1992, when the NCA Amateur Telescope Making group met at both the Chevy Chase Community Center and the Physics Department at American University. A couple of years later, he made an 8" f/6 in the same way. He also visited the Stellafane convention of 1994 and asked lots of questions of other telescope makers. At Stellafane he was rather embarrassed by how crude his own telescope construction was, in comparison to the incredible mirrors and mounts made by the master machinists and amateur telescope makers who regularly display their craft there.

During the mid-1990s, Brandenburg had the good fortune to spend a couple of summers working with the OSSE team at the Naval Research Lab, partly as a mentor to a whole bunch of area high school students under the Science and Engineering Apprenticeship Program. (OSSE was part of the Compton Gamma-Ray Space Telescope that de-orbited back to earth about 10 years ago.) Evidently a few NRL scientists thought that that Guy could be taught both to program computers in IDL and to use various tools in their machine shop to make scientific equipment. They soon had him making coded aperture masks from lead and tantalum for a novel germanium gamma-ray and x-ray detector. Later they had him assemble another detector from cesium iodide crystal bars and diodes. The latter device later became the basis for a small part of the Fermi Gamma-Ray Large-Area Space Telescope (formerly known as GLAST).

Around 2000, Guy was informed by Robert (Bob) Bolster that Jerry Schnall wanted to have somebody take his place as head of the NCA's Amateur Telescope Making group. Not at all feeling confident of his ability to fill Jerry's shoes, Guy reluctantly agreed to give it a try. Since then, he has increased his knowledge of telescope making techniques by visiting Stellafane again, and by participating in two of the Delmarva mirror-making marathons, as well as by picking the brains of everyoner who decided to come by the current Amateur Telescope Making workshop. (Richard Schwartz, Richard Ozer, and John Dobson are three such visitors.)

Guy has led the DC-area Amateur Telescope Making workshop now for about 10 years. He has supervised and aided the construction of scores of telescopes in that in that time, including five small ones made by students in the Saturday science academy at the main headquarters of the Carnegie Institution for Science. He has learned a little bit about how to use metal and wood lathes, band and table and miter saws, drill presses and mill-drills, and vacuum chambers for aluminizing mirrors. He has had to learn a bit more chemistry in order to strip the coatings off of dirty telescope optics.

He has put his French language skills to use in translating some works on telescope-making into English - including Foucault's original 1859 article in the Comptes Rendus of the French academy of sciences on how to make parabolic, silvered glass mirrors.

Guy has way too many projects going on at the present time. One such project is a thin, 16.5" Pyrex mirror that is once again almost polished out. His biggest optical failure is a relatively complex 8" Lurie-Houghton telescope that doesn't work at all, for reasons yet unknown.

Brandenburg has also joined the team that runs and operates the Hopewell Observatory, a small private observatory on Bull Run "Mountain" near Haymarket, VA, built largely by NCA members (some of whom are deceased). He finds that being a member of Hopewell is almost like having one's own mountain cabin, except it also has telescopes. (But no running water yet.)

Weather-permitting, there will be observing through the telescopes after the meeting for members and guests.

Join Us for Dinner Before the Meeting

Join our special guest and members for dinner at 5:30 p.m. in the Garden Restaurant in the Inn and Conference Center University of Maryland University College at University Blvd. and Campus Dr. The restaurant is in the West Wing Lobby Level; they now have new inexpensive menu items just for us.
Dining Establishments Near the UMCP Observatory

Telescope-Making and Mirror-Grinding

Telescope-making and mirror-making classes with Guy Brandenburg at the Chevy Chase Community Center, at the intersection of  McKinley Street and Connecticut Avenue, NW, a few blocks inside the DC  boundary, on the northeast corner of the intersection, in the basement  (wood shop), on Fridays, from 6:30 to 9:30 PM. For information visit Guy's Website  To contact Guy, use this phone #: 202-262-4274 or Email Guy.

Come See the Stars at Exploring the Sky 2011!

Exploring the Sky is an informal program that for over sixty years has offered monthly opportunities for anyone in the Washington area to see the stars and planets through telescopes from a location within the District of Columbia.
Sessions are held in Rock Creek Park once each month on a Saturday night from April through November, starting shortly after sunset. We meet in the field just south of the intersection of Military and Glover Roads NW, near the Nature Center. A parking lot is located next to the field.
Beginners (including children) and experienced stargazers are all welcome-and it's free!
Questions? Call the Nature center at (202) 895-6070 or check: Exploring the Sky @ Rock Creek. Download the flier!

Date Time Targets of Interest
October 22 7:30PM Pleiades and Jupiter rising in the east
November 05 7:00PM Much of Moon sunlit; winter constellations appear
Exploring the Sky is a presentation of the National Park Service and National Capital Astronomers.

Star Parties

For NCA information by E-mail or phone

NCA Documents

NCA constitution and by-laws current as of August 28, 2005 they need some changes so we can continue to be a healthy organization.
NCA constitution and by-laws revision as of October 25, 2005 proposal.

Observing Resources

Navigation Star Chart
Northern Hemisphere Star Alignment Chart
Southern Hemisphere Star Alignment Chart
Astronomical League Observing Clubs, you might use the above alignment charts if you have a GoTo telescope to accomplish some observing.

Site Host

uaqa: understanding articulation quality assurance, home of the National Capital Astronomers, Inc web page. Check out uaqa's web publishing services and the other people and organizations using uaqa.com. uaqa also hosts Astrolabes.org and Mcstaffunion.org.

HOME | Telescope Making Workshops | Exploring the Sky | Contact Info | Star Dust Archive | Links

Updated by Elizabeth Warner at 4:35PM on 17 Dec. 2011.