OAS Executive Committee

President- Ron Vanderhule Ph. (801) 544-9458

Vice Pres- Dave Dunn Ph. (801) 544-7705

Secretary- Bob Tillotson Ph. (801) 773-8106

Treasurer- Doug Say Ph. (801) 731-7324

Vol. 29 Number 11 August 2000 http://physics.weber.edu/oas/oas.html

OAS Meeting Not Scheduled For August

As explained in last month's Star Diagonal, a regular meeting of the OAS will not be held in August. The recent star parties on the Monte Cristo mountain will take the place of the meetings. However, a very interesting exchange is shaping up for the September "Annual" meeting. This upcoming meeting will relate to solar observing and everyone will have a chance to look through a Hydrogen Alpha filter. Stay tuned for further information.

ANTELOPE ISLAND THIS SATURDAY

The August public star party at Antelope Island State Park is scheduled for this Saturday August 5, 2000. Weather permitting, members are asked to support these popular and growing events hosted by the OAS and the Ott Planetarium. Please set up before the slide show starts. OAS members participating in the star party are admitted to the island without the usual fee.

ONE MORE MONTE CRISTO STAR PARTY-CAMP OUT SET FOR AUGUST

Those who couldn't attend the highly successful over night camp out at Monte Cristo in the Cache Wasatch National Forest in July still have an opportunity left. This month's Monte event is scheduled for the weekend of August 25, 2000. Camp sites go fast this time of year so arrive early if you plan to set up camp near the OAS group. If you must come late, there are usually other fine sites in the camp ground's other loops. Pot Luck dinners will be held on both Friday and Saturday evenings around 6:00 p.m. If you have questions or require directions, contact one of the Executive Committee members. See you there!

THREE NIGHTS ON THE MOUNTAIN - A REPORT ON JULY MONTE CRISTO

The forest was beautiful, the temperatures were almost "hot", and since the season seems to be about a month ahead of itself there weren't even any bugs to contend with. That is basically it for the site conditions at the first of two scheduled Monte Cristo over night star parties for this year. Members of the Ogden Astronomical Society took up all but one of the camp sites in the campground's Loop "E" and that remaining site was taken by friends of the OAS. On Friday night there were in excess of twenty telescopes in the meadow, including B.O.B. and the Weber State University's 25-inch Dobsonian (the "PAWS" telescope - Physics and Astronomy at Weber State), ready to view the skies.

For it's First Light outside the Weber State University's campus observatory, Dr. John Sohl brought the 25-inch to the meadow in his utility trailer. The trick is, however, to have no fewer than four strong volunteers to move the telescope. Once in place, the 25-inch assembles easily and is ready for use. Dave Dunn brought out his laser collimator to align the optics which also proved to be a relatively simple job.

Among the attendees at this Monte event was former OAS president Gary Liptrot. Gary works at Hill AFB with Mark Durrwatcher and after a lot of encouragement Gary, who hasn't camped for a long time, caved in and spent a night on the mountain. In fact there were quite a number of first-timers to the mountain this year besides Gary. This was a first for Mark as well and also for the Lee and Carol Priest, not to mention the numerous campground visitors who wondered over to look at the telescopes during the day and put their eye to the eyepiece after sunset.

Speaking of seeing, the only drawback to this star party was the "seeing." In a word, it was awful. Thursday night was the best we had and it wasn't as perfect as we are used to on the mountain. The succeeding days became even worse. The forest and brush fires which are burning up Utah and the other western states right now had thrown an insurmountable amount of smoke and ash into the sky rendering the seeing at least as poor as if viewing from the middle of downtown Ogden; not good. But this didn't render the trip a wash. There was plenty of time for Tea Parties and the Pot Luck dinners were some of the finest ever. If you don't come home a few pounds heavier after these events it is simply because you weren't trying.

One of the most interesting new toys acquired by an OAS member, Dr. Bob Neill, is a Coronado Instruments, Ltd. H-alpha solar filter. Bob has had this instrument on order for over a year. It arrived just in time to bring it to Monte Cristo. This is a type of passive H-alpha filter. It uses three types of filters to isolate the ultra-narrow H-alpha spectral line, (see the September issue of Sky and Telescope magazine for details, Dr. Sohl will give a special demonstration/presentation on how this filter system works at the September OAS meeting).

Bob uses a Tele Vue 4-inch f/5.3 refractor for the solar filter. We used various eyepieces to render different magnifications. The view was amazing. Looping prominences, plages and edge on filaments, which looked like cracks in a vase, were visible.

There are several sizes of filters offered by Coronado. The one Dr. Bob is using has a 40 mm energy filter outside of objective lens thus keeping the heat out and the danger minimum.

This Monte trip proved a fun and exciting experience in spite of the poor seeing and, there is more to come this month. Bob Tillotson

August Crossword Challenge

The "SUN" by Jeremy Mathews

Answers to last month's: