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A S T R O N O T E S ISSN 0048-8682
The newsletter Magazine of the Ottawa Centre of the RASC
Vol. 22, No. 1 $5.00 a year January 1983
Editor.......Rolf Meier......4-A Arnold Dr.....820-5784
Addresses.....Art Fraser......11-860 Cahill Dr...737-4110
Circulation...Barry Matthews...2237 Iris St......225-6600
OBSERVER'S GROUP MEETING - DECEMBER 3, 1982 David Lauzon
Chairman Rolf Meier opened the meeting at 8:31 with 44 people in attendance, 6 of whom were non-members. Rolf announced various R.A.S.C. activities to occur this month.
Next up was our new President, Peter MacKinnon, to introduce our guest speaker for this evening, Professor Preston Cloud, of the University of California, Santa Barbara. His talk was about Planetary Evolution: A
Terrestrial Perspective. Professor Cloud talked about the origin of the solar system and some of the possible reasons for the finding of isotopes not believed to have been formed on the earth. Some of the theories discussed tried to explain the causes of planetary distributions and continental drift.
Rob McCallum was up next to introduce our occultation coordinator Brian Burke, who gave information about occultations to occur during the December 30 total lunar eclipse.
Next up was Dave Lauzon, our meteor coordinator, who presented a talk on December meteors.
Rob McCallum gave some interesting information about meteor observers of past and present.
Gary Susick was then up to show his new method of polar aligning his C-8.
Barry Matthews was up to remind members hOw to use the new heaters at I.R.O.
Rolf closed the meeting at 10:15 and people were invited to stay for coffee, coke, and cookies.
* * *
- 2 - CALENDAR OF COMING EVENTS
Monday, January 3 Quadrantid meteor shower
Friday, January 7 Observer's Group Meeting
Friday, January 14 new moon
Friday, January 21 Astronotes due date
Friday, January 28 full moon
Friday, Februay 4 Observer's Group Meeting
10 YEARS AGO IN ASTRONOTES
from the January, 1973 issue: "On Dec 2, four Ottawans and one Vancouverite rocketed south to witness the Apollo 17 lift-off. Twenty-eight hours later Ken Hewitt-White, Joan Hoskinson, Rolf Meier, Jon Buchanan and myself crossed into the, Sunshine State...at T - 30 sec they held the rocket for 2 1/2 hours. Finally the countdown resumed and before you knew it first-stage ignition took place. Within seconds a huge fireball surrounded in billowing smoke resulted. Eight seconds and four f-stops later the rocket rose majestically from the fiery pad. Just before the Saturn cleared the tower the deafening sound was upon us. The crackling and roar was pounding so hard and quickly that it nearly knocked me over (evidence of movie)." by Allen Miller.
COUNCIL FOR 1983
The council of the Ottawa Centre of the RASC, elected at the annual Dinner Meeting on November 26, 1982, is as follows
President: First V.P.: Second V.P.: Secretary: Treasurer: Librarian: Recorder: Councillors: Peter MacKinnon Robert Dick Brian Burke Robin Molson Fred Brisson Stan Mott
Art Fraser Malcom Knock Barry Matthews Robert McCallum Frank Roy
National Rep.: Peter MacKinnon * * *
(COORDINATORS FOR 1983
The coordinators of the Observer's Croup of the Ottawa Centre, elected at the November 5 meeting, are as follows:
Chairman: Vice-Chairman: Recorder: Meteors:
Variable Stars: Comets and Novae: Planets:
Occultations: Instrumentation: Astrophotography: Rolf Meier Gary Susick Dave Lauzon Dave Lauzon Brian Burke Dave Fedosiewich Barry Matthews Gary Susick Rob Dick Frank Floy Brian Burke Malcom Lambourne
Articles for the February issue of Astronotes are due
by January 21.
METEORS IN 1983 David Lauzon
After browsing through the 1983 Observer's Handbook, I noticed that the phase of the moon for major showers this year is out of phase with last year's showers.
This is because the average Gregorian month of about 30.5 days is different from the synodic month, which is about 29.5 days. This difference of about 1 day per month puts the moon 12 days out of phase from one year to the next. So therefore, a date which might be favourable one year could be washed out by the full moon the next year. Fortunately, not all of the major showers are so evenly spaced apart so as to cause all showers one year to be washed out.
Last year, out of the 10 major showers, 8 were favourable at the time of maximum. Only 2 showers, the Eta Aquarids and the South Taurids occurred during the full moon. This year these 2 showers occur somewhere between the last quarter and new moon.
This year, 3 showers are washed out by the full moon. They are the Orionids, the Leonids, and the Ursids, which last year occurred around the first quarter.
What this shows is that every 3 to 4 years, a shower is washed out by the full moon, because of the moon's relative phase changing from year to year.
This year, the showers that occurred during first quarter moon last year will most likely be washed out this year.
The showers that occur this year are on pages 122 and 123 of the Observer's Handbook 1983.
The shower for this month is the Quadrantids, which peak on January 3. This is the time of the last quarter moon. This shower can best be seen during the wee hours of the morning, and must be observed within a day of each side of the maximum. This makes the shower unfavourable this year. On the 3rd the moon rises at around 9:37.
PRIME FOCUS PHOTOGRAPHY Frank Roy
This is by far the most difficult type of astrophotography. At I.R.O. the components necessary are available, although the T-adapter is of the universal thread type. It should be noted that most cameras today use a form of bayonet, so the T-adapter at I.R.O. would not work. Also, a T-adapter with the large screws would make its use easy.
One warning, the Zenit camera will not focus with the 16-inch because the camera cannot get close enough.
In prime focus photography, the image is formed by the objective of the telescope directly.
Usually a bright star is used to focus the camera. This is done by pushing the camera in and out of the focusing cylinder. Once the camera is focused, the telescope is pointed to the object to be photographed and centred using the camera viewfinder. Next, a guide star is found using the guidescope on the 16-inch. Once the star is centred, a 2x barlow should be used with the 12.5-mm guiding eyepiece. The lighted crosshairs should be aligned with RA and Dec by rotating the eyepiece.
The longer one can make the exposure the better, but because of flexure problems between the telescope and the guidescope, exposures longer than about 20 minutes usually show trailed star images.
Guiding is accomplished using the 4 buttons on the control box. They allow minute tracking errors to be corrected.
If anyone wants to do photography on the 16-inch, I would be glad to lend a hand. Good luck.