ATM 6" Mirror/Binoscope

Currently, I have a polished but not parabolized 6″ f/5 plate mirror made. I may get to test it later this year but I need to work out the bugs of the Foucault tester.

Grinding it went well as can be expected without any major problems, with no pits showing up after polishing. I used a tile tool, rather than the more standard glass tool as I wanted to use this small piece of glass for practice.

In other news, I will go ahead with the roughing in of the two pieces for a binoscope. I plan on using two tools, working each one for a set amount of time, switching, then continuing on. This should give me a pair of blanks with the same ROC, provided I switch them often enough. The blanks are both pyrex this time from Willman Bell and being tougher than plate, the ROC will only move with a lot of effort.

I was going through old S & T magazines (a great resource BTW, a much better magazine then than it is now) and found an article [Dec 1979] by Sinnott on a 6″ binoscope. I had seen it before and was going to file it but its unusual optics caught my eye.

It featured an unobstructed light-path that allows the pencil of light to exit the tube through the side into prisms that rotate and invert the image. With 3 additional reflections (all internal, less light loss) you end up with a normal view like a true binocular.

The only problem is that while you grind them like a 6″ f/6, you need to parabolize them like a 12″ f/3. This means each mirror has to be deepened in an offset manner. How far offset depends on how much you want the light pencil from center. This also means a very difficult Foucault Test.

 

I have an idea what to do with this mirror: Build a scope out of it in a Dob base, and leave it in a case at the Elvin Lakes shelter in Garabladi Park

Lots of people with kids go up there and what better place to enjoy the wonders of the night sky than a dark place like this?

NOVA Newsletter: Mount Kobau 2008 Star Party Report, etc.

NOVA is the RASC Vancouver Centre bimonthly newsletter.

From the  current edition:

Mt. Kobau Star Party Report 2008

“…. Tuesday night was a wonderful night with the Milky Way bright and visible from horizon to horizon. Pomponia’s 12-inch dob and Ron Jerome’s 16-inch were having a great time finding faint fuzzies with M82 being especially entertaining. ….”

Previous editions are available in the archives.

October 9th: Observations of a Telescope Designer – Building the Thirty meter telescope

This is the Royal Astronomical Society of Canada – Vancouver monthly meeting.

Craig Breckenridge and members of the world’s premier Observatory design team at Empire Dynamic Structures took a trip to see the facility currently hailed as the largest optical telescope in the world. This marvel of engineering is soon to be eclipsed by the construction of the Thirty Meter Telescope which is currently being designed by this local company located in Port Coquitlam. Facets of the LBT’s design seldom seen by outsiders will be presented in all their glory with commentary by our resident expert designer.

We meet at 7:30 p.m. on the second Thursday of each month, downstairs in the auditorium of the H.R. MacMillan Space Centre.

Free Admission, Open to the public

Astro-coffee and astro-cookies will be served at the Southam Observatory after the meeting.

Happenings – Monthly meeting (Sept. 11th 7:30pm)

Bob Parry , Director of Telescopes on the RASC Council, will be setting up and talking about the new telescopes available to members in the loaner program.

Speaker to be announced.

We meet at 7:30 p.m. on the second Thursday of each month, downstairs in the auditorium of the H.R. MacMillan Space Centre.

Sept. 13: THE 2008 PAUL SYKES LECTURE ON ASTRONOMY – "Mapping the Lakes and Rivers on Saturn’s Moon Titan"

Location: Room 201 of the Hennings Physics Building at UBC (adjacent to the SUB)
Description: THE 2008 PAUL SYKES LECTURE ON ASTRONOMY

This year’s speaker is Guinness Book of Record holder Dr. Rosaly M.C. Lopes from NASA’s Jet Propulsion Laboratory. Her talk: “Mapping the Lakes and Rivers on Saturn’s Moon Titan” will show us just how similar the Earth is to the largest moon in the solar system.
Start Time: 19:00
Date: 2008-09-13

This year’s speaker is Guinness Book of Record holder Dr. Rosaly M.C. Lopes from NASA’s Jet Propulsion Laboratory. Her talk: “Mapping the Lakes and Rivers on Saturn’s Moon Titan” will show us just how similar the Earth is to the largest moon in the solar system.

Dr. Lopes is a Principal Scientist at NASA’s Jet Propulsion Laboratory and Lead Scientist for Geophysics and Planetary Geosciences. Her major research interests are in planetary and terrestrial geology and volcanology. Continue reading “Sept. 13: THE 2008 PAUL SYKES LECTURE ON ASTRONOMY – "Mapping the Lakes and Rivers on Saturn’s Moon Titan"”

July 10, 2008 – Great Moments in Planetary Exploration

Time: 7:30 PM
Location: H.R. MacMillan Space Centre, downstairs auditorium
Topic: “Come along for a trip down memory lane as we review the Great Moments in Planetary Exploration.  Our path will go from Mercury to Pluto and beyond.”
Speaker: Aaron Clevenson

Aaron Clevenson is an Astronomy Professor at Lonestar College in Houston, Texas in the US, Observation Chairman, and past president of the North houston Astronomy Club.

Free Admission, Open to the public

Astro-coffee and astro-cookies will be served
at the Southam Observatory after the meeting.