OAS Executive Committee President- Lee Priest Ph. (801) 479-5803

Vice Pres- Cliff Peterson Ph. (801) 782-4378

Secretary- Jim Seargeant Ph. (801) 479-4050

Treasurer- Doug Say (801) 731-7324

Vol. 32 Number 3 December 2002 http://physics.weber.edu/oas/oas.html

The President's Message

It was a last minute choice to get away from the city lights and head up Trappers Loop to view the Leonids. At 2:30 AM the drive up, reminded me of Washington Boulevard on a Friday evening. Every pull out had one or two cars; some had groups of people standing around heaters looking out at a partly cloudy sky. By 3:15 Ursa Major was about the only Constellation visible, by 3:30 Leo was clear and we were seeing 5 or 6 meteors a minute. The sky continued to clear off to the south, Orion came into view and the moon was clear by 4:00 but clouds moved back in shortly after. All total we saw 50 meteors or so, about 10 bright ones. Last year was much better, but this trip was well worth it.

We will have the Apollo 11 video for the Dec meeting.

Lee Priest, President

OAS Minutes

14 November 2002P resident Lee Priest opened the meeting at 7:34 P.M.

Announcements/discussion:

Dave Dunn described the Golden Spike National Monument star party on 8, 9 Nov. Saturday night offered good skies until about 10:30, but then the clouds closed in.

Several OAS members will make an effort fo find clear skies to view the Leonids Monday night, 18-19 November. With too much snow and snowmobiles at the pullout toward Monte Cristo, the promising sites were all to the south. Skull valley, the Parawon Gap, even Cedar City were offered as possibilities. A decision will be made Monday morning.

Lee announced the Year in Space desk planner order is being put together; Carol is collecting orders. If the total order is less than 10, the price is $9.95; for more than ten it's $8.95.

The beginner's class introduced by Cliff Peterson last month was discussed. A class before Christmas may help in choosing a telescopeto put under the tree. A indoor session from 7 to 8 P.M. followed by a star party, weather permitting, seems to be a good format.

Another Mars opposition trip to Lowell Observatory near Flagstaff is being planned for 8 - 10 Sep 03. These will be OAS only nights to insure plenty of time at the eyepiece. Anyone interested in going should contact Dave Dunn.

Several extra-large, blue OAS T-shirts are still available; contact Doug Say.

Doug also exhibited the OII filter just purchased for the club. It is advertised as a 2" filter, but does not tighten firmly into the club's 2" eyepiece. Teflon plumber's tape was suggested as a way to firm up the threads.

The order for the Coronado SolarMax40 telescope/filter was confirmed. The OAS has put $300 down, with the balance due upon shipment.

John Sohl made another call for those who had ordered the "Observer's Handbook 2003" and the "Beginner's Observers Guide"

Lee then introduced the night's program, Show and Tell.

John Sohl and Doug Say presented a video of their flight in Doug's powered para-sail over Mount Ogden. John had a bit of trouble with his camera and Doug's hair, but the flight looked to be a lot of fun. They both did survive, after all!

Lee discussed the 16" Dob he's building with Dave and showed off the 18 point cell he's making for it.

Gary Liptrot showed off the Foucault and Ronchi tester he made based on the plans from the Stellafane web page. (See his following description.) He is also working on a Mel Bartels' scope drive for the Dob mount. Another project is setting up his foundry so that he can make aluminum castings.

Dave Dunn brought out one of his 8" Newtonian tubes with a new, 3-point mirror mount and curved spider for the secondary. He also described the new book he bought from Brent Watson, "Select Double Stars".

Andrew Pratt demonstrated very powerful neodymium rare earth magnets, warning everyone to keep their credit cards clear.

Ron Vanderhule showed off large sheets of polarizing material, a flexible pitch lap mold, and a Daisy red-dot finder with large field of view and adjustable brightness. (After seeing Ron's, I found mine at Gart Bros. Be sure to get the Max View version; Daisy also sells one with a smaller aperture and no brightness adjustment.)

Dale Hooper announced that he would try to set up another get-together at his new observatory in Hyde Park.

Lee closed the meeting at 9:21, and we all converged on the goodies that had been presented.

Leonids Report

I went down to Parowan Gap. At 8:55pm I saw a bright green bolide. It came in just south of Cassiopia. The interesting thing was that it appeared to hit a cloud bank. Just as it reached the cloud bank, it lurched, a little bit broke off and the main meteor continued under the cloud cover. I am not sure this was possible so it may have just been my viewing angle. I eventually went to bed and woke up at 2am. I thought they put on a good show. I counted bursts of 10 or more a second. I also noticed that most of what I saw was looking right at Leo. There were a lot of short bright meteors right near the radiant. The longer ones that I saw were going toward Canis Major. At around 3:50 the clouds got pretty thick. At about 4:30 I went back to bed.

I know last year I saw more meteors, but that was without the moon. I think this year may have exceeded last year if we could have seen the dim meteors bouncing all the way across the sky. It was definitely worth the drive to the south.

Dave Dunn

See www.spaceweather.com for their gallery of Leonids photos

Jim Seargeant

"Select Double Stars"

Several people asked me to have Brent Watson bring copies of his Double Star book to the December meeting. He accepted the invitation and will bring the books to our meeting. The cost with tax is $21.25.

Dave Dunn

Sunspot Closeup

Several sources, including the Utah-astronomy mailing list (http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy), have recently pointed to some extraordinary images of our sun taken by the new Swedish 1-m Solar Telescope. See http://bellman.astro.su.se/solar.

Jim Seargeant

Upcoming Events

12 Dec, 6:30 PM OAS executive session, Room 121

12 Dec, 7:30 PM OAS meeting, Room 121 (New room for this meeting!)

25 Dec Merry Christmas!

Last Call for Dues!

Sorry, gents. December will be the last month you will receive The Star Diagonal if you haven't paid your dues. Check your address label. If there's an "*" next to your name, you've paid. If not, not. Contact Doug Say to pay or let us know we missed you.

Foucault or Knife-Edge Tester and Ronchi Tester

Site to download your own plans: http://www.stellafane.com/atm/atm_foucault_tester/atm_tester_main.htm

Dial Gauge - bought at Harbor Freight for $6.95 on sale or $12.95 not on sale. It says it is accurate to 0.001 inch and is easy to read.

Adjustment Screws for the two axis - 1/4-20 carriage bolts with Radio Shack volume knobs attached to them. I didn't like the dual T-Nuts that the plans called for. They are too hard to line up. Instead I got a 1/4-20 nut (don't know what you call them) that is about and inch long. I drilled a hole that would fit the hexagonal shape of the nut real tight on my boards and pounded the nut in. Works great, no wobble and smooth as you need it.

Ronchi\Foucault Mountings - Plastic Photographic Slide Mounts. One with a razor blade in it for the Foucault test and one with a 150 LPI (Lines Per Inch) Ronchi Grid obtained cheaply on acetate from Orion. I bought three on a strip just in case... B)

LED - Jumbo Green LED from Radio Shack. The front is cut off and sanded roughly to produce a diffusing action on the light. The ATMers (Amateur Telescope Makers email list) seem to think that Green is the best color for visual detail and contrast. I added a Potentiometer to my electrical setup because you just never know what kind of ambient light you are going to be testing the mirror under.

Springs attached to Cup hooks provide the return tension that acts against the adjustment screw on the Carriage. The bottom of the Base has a 1/4-20 T-Nut in it so it will attach to a camera tripod for easy adjustment and viewing.

My favorite site for studying and understanding the Foucault Test. David Anthony Harbour does a great job,

http://www.atmsite.org/contrib/Harbour/Foucault.html.

[Click on image for full size view.]

[Click on image for full size view.]

Gary Liptrot

Jim Seargeant's Images

It's embarrasing how long film stays in my cameras, sometimes. I recently hauled out my old Canon F1 and noticed there was film in it. What could this be? I had completely forgotten about the annular eclipse of the sun this summer on 10 Jul. This was seen as a partial eclipse here, with the path of totality starting off the southern tip of Baja, swinging north of Hawaii, and then south again to Indonesia. These photos were taken through my old Century Precision Optics 650mm telephoto lens at f/11, 1/125 sec exposure, Kodacolor 200 film, and using a Baader solar filter. The negatives were scanned with a Polaroid 35 SprintScan Plus and processed using Corel Photo-Paint.

One of the penalties of forgetting what was on the film was that I gave no special instructions for processing. With no clear separation between frames - black background everywhere - the processor was not able properly cut the negatives and several of the images of the sun were cut in two. Reminder: when you shoot astro images, you gotta tell the photo processor to leave the filmstrip uncut.

These grayscale images don't show the images very well. You should be able to see the small sunspots, granulation, and limb darkening that are visible in the color images posted with this issue of The Star Diagonal at the OAS web page hosted by the Weber University Physics Department.

Jim Seargeant

[Click on image for full size view.]