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The Newsletter Magazine of the Ottawa Centre of the RASC
Vol. 24, No. 1 January, 1985
Editor..... ..Rolf Meier......4-A Arnold Dr.......820-5784
Addresses.... Art Fraser......92 Lillico Dr....... 737-4110
Circulation...Robin Molson....2029 Garfield Ave...225-3082
OBSERVER'S GROUP MEETING - DECEMBER 7, 1984
Chairman Gary Susick opened the meeting at 8:23 pm with 44 people in attendance, of whom 36 were members.
Ofthe various recent events, the New Member’s Night at IRO was a success.
Meteor coordinator David Lauzon resigned from his coordinatorship and elections for this post were held. Frank Roy was nominated and will fill this position
as of January, 1985.
Centre President Brian Burke was up to say a few words on the various committees of the Centre. Anyone wishing to serve on a committee should contact him.
Gary Susick was up again to discuss the recent Annual Dinner Meeting.
The Observer of the Year Award, the Variable Star Award, and the Best Astronotes Article of the Year Award all went to Linda Meier. Ken Tapping won the Centre's Merit Award. Congratulations to both for their outstanding work.
Gary then proceeded to introduce the new chairman for 1985, Doug George. He also mentioned that anyone wishing to give a talk on any subject should contact the chairman, or the coordinator in charge.
The main speaker of the evening was Ken Tapping, with a talk on the May 30, 1984 eclipse of the sun. Ken used a 30-inch radio telescope to observe the eclipse from his back yard, listening in on the 2.8-cm wavelength. His telescope could only resolve a 2° area of the sky, so Ken tried to pick up the stepwise occultation of radio sources on the sun’s surface as the moon passed by. By knowing the approximate location of each source, its size and exact location could be found. Ken stated that this is a good experiment that amateurs can do.
Meteor coordinator David Lauzon was up to say a few words on upcoming meteor showers. The Geminids, which peak on December 13, promise to be a good shower, as will the Ursids, which peak on December 22. The Quadrantids, which occur on January 4, will not be visually observed due to the full moon.
Brian Burke gave a talk continued from last month. This talk involved the concepts of geocentric, geographic, and astronomical latitude, their similarities, and differences. The major deviation between these types of latitude are maximised at a latitude of about 45°. Fortunately, there is a 1:1 mapping between geographical latitude and declination. For more information, one is advised to refer to page 13 of the Observer's Handbook.
Astronotes editor Rolf Meier was up to say a few words about our centre’s magazine. Astronotes now has a new feature of producing pictures by the use of a half-tone. Member Roy Fox does this task. Volunteers are needed to assist in the assembly of Astronotes.
Rolf stated that one of the hardest parts about putting Astronotes together is the lack of articles.
Some ideas for article submissions are:
1) upcoming astronomical events,
2) upcoming meetings,
3) reports on 1) and 2),
4) project ideas, observational and instrumentation,
5) humour, puzzles, and quizzes, and
6) photos and drawings.
Rolf also noted that articles should be in on time.
Pierre Deguire presented a talk on his home-built drive corrector for his C-8. The few disadvantages of his corrector are outweighed by the advantages. The drive, without declination motor, may be built for under $100, depending on your resources. Pierre then showed pictures of Jupiter, Saturn, M 13, M 17, M 31, M 42, and M 104.
Frank Roy presented a talk on the Zodiacal light and a possible picture of one. He explained what these lights are and where their source is.
Simon Tsang presented a slide and tape show on the explorations of Viking on Mars.
Gary Susick closed the meeting at 10:30 when people were offered refreshments.
* * *
Articles for the February issue of Astronotes are due by January 20. I will be just getting back to Ottawa from vacation at that time, so I hope that it will be ready in time for the meeting.
COUNCIL MEETING - DECEMBER 11, 1984
Who says Council meetings are boring?
Long...well maybe. You can decide now because this marks the beginning of regular reports for Astronotes of the content of these meetings.
After the formalities of calling the meeting to order, we quickly went through the first half of the agenda which were:
Review of Minutes, Business Arising from Minutes, Membership Report, Financial Report, and Dinner Committee Report.
On the business of membership, Art Fraser advised that there are presently 176 members, 60 more than last year at this time. More are expected to join in the next few months.
Sandy Ferguson told us that the financial statements are complete, but require the approval of the auditor after the new closing out figures are entered. The statements had been handed out to those who attended the Annual Dinner Meeting. For those of you who were not able to attend, the bottom line is that Centre revenues were $4,694.86 and total expenses were $2,750.26, leaving a surplus of $1,944.60. Costs are probably kept down due to all the terrific people volunteering their time and money towards the club.
Rob McCallum was not at the Council meeting to provide his report on the Dinner Meeting; however, this year the dinner cost $1,040.11 and $945.00 in tickets were sold, leaving a deficit of $95.11.
Next on the agenda came the Centre Questionnaire. This entailed quite a lot of discussion, which is likely proportionate to its importance. The purpose of this questionnaire is to find out what our members are doing or want to do, how we can best serve the membership, and how they heard about the RASC. These will come as a separate mailing and your cooperation in replying will be most appreciated.
Another item we covered was IRO assessment. Proper insurance coverage on the 16-inch must be adequate. Sandy Ferguson will be ensuring that this will be done. The 16-inch is a very special customized piece of equipment, very difficult to replace not only in terms of its uniqueness but also in its sentimental value.
Frank Roy has generously offered to provided address labels to the Ottawa Centre as problems have arisen since Andy Woodsworth left the NRC. Frank has an Apple computer system with a high-speed dot matrix printer. Thanks are extended to Frank for his volunteering.
New blood brings new ideas and/or change and Brian Burke is no exception. Brian has decided to cut out some of the old committees which had become redundant and has created a new one called the Transportation Committee. This committee means that people (ie students) who do not have easy accessibility to the observatory, not to mention meetings, may now have that chance. Of course, we have to count on our other members to help out, but at least we will have a focus to organize rides for members.
Recently, Brian received a letter from a former Saskatoon member, who has now moved to Ottawa. He is working with Cablevision, and has proposed doing an astronomy show for the station. The Publicity Committee will be reporting further on the status of this proposal.
Other business arising during this meeting was a matter concerning the Recorder and Treasurer position. As you know, Sandy had been elected as Treasurer and me as Recorder. Due to Sandy’s overloaded schedule, we agreed and Council agreed that I will now be Treasurer and Sandy will be Recorder. So, this is my first and last report to you, but certainly not the last you’ll hear from me.
I also took the opportunity to bring up the matter of the Outhouse at IRO, which has taken a turn for the worse (if you can believe that it can get worse!). It is horizontal again. Robin Molson replied "Work will commence in the Spring." It was to have been completed in the fall, the one just past, but I guess our nagging really didn't work, eh Sandy?
* * *
An Ad Hoc Committee has been formed by the National Council of the RASC to investigate a computer network for the RASC for the purpose of exchanging programs, providing news, etc. It would like the following information from RASC members who have computer systems:
Name, Address, Telephone, Computer make and model, Modem make and baud rate, and Printer make.
Members should send this information to:
Mr. Franklin C. Loehde, Chairman
Computer Utilization Committee
11107- 63 Street
CHAIRMAN'S REVIEW OF 1984
December 1984 marked the end of a very successful year for the Observer's Group. It was a year of transition with many established OG activities being continued in addition to several new events and ideas being tried for the first time. The “regional” star parties established in the past
were continued and expanded. Utilizing the media, especially radio and TV, brought more to focus this activity and resulted in a large public response.
Instrument night was well received with many current projects being exhibited. Work continued on various acivities including a dual axis drive corrector and a portable photographic equatorial mount. Included in instrumentation was the upgrading of the IRO clubhouse with masonite siding and a roll-off shed for the 10-inch Newtonian telescope. These professional improvements make IRO an excellent observational facility, among the best in the RASC.
New activities included the participation of the Ottawa Centre in International Astronomy Day. In conjunction with this, and astronomical display at a local shopping centre helped to enhance our visibility in the Ottawa area. A public school star night and a New Member's star night were also successfully held.
1984 proved to be challenging yet enjoyable. Building on proven activities and adding new ideas allowed greater exposure to our members as well as the general public. Membership increased with a subsequent renewed enthusiasm and vigor being injected into the Observer's Group.A great deal of success can be directly attributed to the excellent cooperation I received from the vice-chairman as well as the various coordinators.
Acting as chairman for 1984 was a rewarding experience. I made many new friends as well as strengthened old friendships. The Observer's Group will
continue to prosper under the guidance of the new chairman, Doug George.
Good luck to the 1985 chairman and the new slate of coordinators.
* * *
In 1985 there will be 4 eclipses, 2 of the sun and 2 of the moon. None of them will be a good show for residents of Ottawa (unless they go somewhere else).
NEW METEOR COORDINATOR
Dave Lauzon was our meteor coordinator for the last 3 years. He is passing on his coordinatorship to me. He is a student at Carleton University and feels that he will no longer have the time to be a good coordinator. However, he assures me that when time permits he will join us at Quiet Site or IRO to observe meteors. I would like to thank Dave for his efforts in continuing the meteor group which in the past was the backbone of the observational section. Over the years a number of people have held the post of meteor coordinator, and at one time the coordinators were appointed by the executives (ie chairman and vice chairman) of the Observer’s Group. I have gone through my old Astronotes and found that this will be my 4th year as meteor coordinator.
Following is a list of past meteor coordinators:
year meteor coordinator
1967 Peter Ryback
1968 Les MacDonald
1971 Ken Hewitt-White
1972 Ken Hewitt-White
1973 Ken Hewitt-White/Chris Martin
1974 Chris Martin
1975 Rob McCallum
1976 Rob McCallum
1977 Rob McCallum
1978 Rolf Meier
1979 Frank Roy
1980 Frank Roy
1981 Frank Roy
1982 Dave Lauzon
1983 Dave Lauzon
1984 Dave Lauzon
1985 Frank Roy
In 1985 I intend to have several meteor sessions, covering all the favourable showers. This year, special attention will be on the annual Perseids, which peak at new moon. Also, the maximum on August 12 (06 h UT) happens to fall on a Monday, so that weekend will be very favourable.
The Geminids and the April Lyrids also fall on a new moon with several other annual showers well mooned for observation.
IRO and Quiet Site will be the major observing stations. Meteor observing is a lot of fun and a good way to learn the constellations. Also, it provides a good way to meet other people in the group. I can provide transportation for 3 or 4 people but it would be appreciated if members with other cars would help me here. I intend to make the meteor team very active and a prominent part of the Observer’s Group.
If anyone needs transportation for any upcoming meteor session please call me at 820-0874.
* * *
ANNUAL SOLAR AND AURORA REPORT
The sun, as you are probably aware, has been and still is quite inactive, which is as it should be, considering that the minimum of the present cycle is coming soon. This is to occur in late 1986 or early 1987.
Despite this gloomy picture there are still times when spots do appear. This makes it all the more exciting because after all the times you may have to set up to see nothing, you can at last observe a spot, which is all it may be. However, earlier this year saw quite a lot of sunspots, so continued and persistent observations should be made whenever possible.
There is something else that I intend to try this year and that is to set up a short-wave detection of solar flares. I read about this in the November 1984 issue of Sky and Telescope. After all, just because spots aren’t covering the disc of the sun certainly dosen’t mean that it’s dead or that there is nothing else one can do! As soon as I am able to start this project (you can call me too if you are interested at 820-5784) you can expect progress reports or maybe even some interesting results.
In the Observer’s Handbook under Solar Activities, another project mentioned is the observing of white light flares. These are not easy to see, but it makes it all the more challenging. The only problem now is that they occur with sunspots. They have a very short time when they are intense, unlike light bridges, so you will have to be careful in observing them. They seem to occur in quickly-forming sunspot groups. To quote the Handbook, "They are most likely to occur in complex, rapidly evolving sunspot groups with many closely packed umbrae enclosed by a single penumbra."
You may recall in Astronotes last year a summation of aurora events during the period October 1982 to October 1983. On December 13 Rolf and I went to the observatory and at that time I checked back through the log book to gather the data for an aurora report this year. However, this year's summary covers the period from January, 1984 to December 1984 as I had not checked back to the time frame used last year...oh well.
For 1984 I counted 61 clear nights that members attended IRO and on 22 of those nights aurorae were reported. For comparison, last year 20 aurorae were reported out of 55 clear nights. In 1984, two of the aurorae were quite intense with spikes, quickly-moving curtains, bright enough to cast shadows, in other words
everything that makes an aurora the spectacular event it can be.
Again, aurora activity was predominant in the spring and fall.
* * *
PHOTOGRAPHIC DETERMINATION OF METEOR HEIGHTS
As an amateur astronomer, I have frequently wondered how scientists quantitatively determine theories and laws of the universe. Such "greats" as Archimedes and Galileo have laid down the foundations of science on which we walk.
Now, we as amateurs can use these foundations and our expertise in an excercise in astronomy. In estimating the height of a meteor, one may think of this as a difficult task. In fact, it is relatively easy by using simple trigonometry. A summary of how to find meteor heights follows.
Collecting Raw Data and Conversions
The right ascension (RA) and declination (Dec) of a meteor may easily be found photographically. The idea is to take a long exposure during a particular meteor shower and hope that a bright meteor will pass through the field of view of the lens. At this point, the exposure should be stopped, to stop the film from recording any more length to the trails. In this way it is possible to determine the RA and Dec of the meteor trail against the background stars, by using the end points of the trails.
A meteor passing completely through the field of view will not provide the crucial termination point needed for later calculations. The time the meteor was seen is also important for converting celestial coordinates to azimuth and altitude. From two separated stations, the star and meteor trails will appear as shown in figure 1, opposite. The meteor's celestial coordinates can be found by comparing the termination point to the reference stars. A parallax should exist in the two trails if two separated stations record the same meteor.
To convert the RA and Dec into azimuth and altitude, the following equations may be used:
h = t - a (1)
sin(b) = sin(d) * sin(L) + cos(h) * cos(d) * cos(L) (2)
cos(d) * sin(h) = -cos(b) * sin(A) (3)
sin(d) = sin(b) * sin(L) + cos(b) * cos(A) * cos(L) (4)
a = RA
h = hour angle
d = Dec
A = azimuth (measured east of north)
b = altitude
L = latitude
t = sidereal time
These calculations may be performed on a computer, such as the BASIC program in the August, 1984 issue of Sky and Telescope.
Now that the conversion from RA and Dec to altitude and azimuth has been done for each station, simple trigonometry will be used. For our purposes, we shall
assume that the earth is flat, and we can correct for this later.
The 3-dimensional geometry of 2-station photography may be found in figure 2 (below).
From this diagram, the height of the meteor may be determined as follows. (note: calculations are modified for the positive octant)
XY = C = known distance from a map
XZ = B
YZ = A
ZXY = angle a = azimuth of Y from X - azimuth of meteor
XYZ = angle b = (360-az of X from Y) + az of meteor
XZY = angle c = 180 - (angle a + angle b)
By using the following relationship, the sides A and B can be calculated:
the lengths of sin(a)/A = sin(b)/B = sin(c)/C
The height of the meteor can now be calculated from this data. Since the tangent of the meteor’s altitude is equal to the lengths of the opposite side divided by the length of the adjacent,
tan(altitude) = h/adjacent
so therefore h = adjacent * tan(altitude)
From station X: h = B * tan(d)
and from station Y: h = A * tan(e)
A correction factor for the curvature of the earth will now be implemented. The correction depends on the length of the adjacent side. Some correction factors may be found in table 1 (below).
table 1 -
A or B:
c - correction factor
The adjusted height of the meteor may now be given by the equation:
h = A * tan(e+c) = B * tan(d+c)
To actually go out in the field and try this exercise is harder than it appears. Here are a few pointers which will limit the confusion:
sky fog: Exposures no longer than 10 minutes should be used.
From IRO, this will show no problems due to the dark skies there.
From Quiet Site, on the other hand, exposures to the east may be limited to 5 minutes.
timing: The exact time that the meteor was observed is not required, but timing in the order of a few seconds is essential. The time is needed for the conversion of RA and Dec to altitude and azimuth. A CHU receiver and tape recorder should prove to be handy.
positioning of the cameras: From the 2 stations, the 2 cameras must survey the same area of the atmosphere where the meteors occur. Therefore, both cameras should have the same field of view and focal length. Clock-driven cameras are preferred over stationary cameras. The stations should be between 80 and 200 km apart for best results.
recording: The camera operator and/or recorder should keep a record of the exposures taken and the times in a log book.
With all of this in mind and a bit of luck, the amateur is now equipped to find the height of a meteor. It may take many hours of exposures to finally get results, but it should prove worthwhile!
1984 , edited by Roy L.
University of Toronto press, 1983
Sky and Telescope , June, 1984, "Astronomical Computing" by R.W. Sinnott
Observational Astronomy for Amateurs , by J.A. Sidgwick,
Faber and Faber Ltd, London, 1971
The schematic has 2 versions of Sht 2. Use Sht 2A if your drive is set for sidereal rate. Use Sht 2B if it is set for solar rate.
Note 2 on sheet 2 - The resistor value is not critical. Anything in the range of 1 to 10 Mohm will work.
Note 3 on sheet 1 - These resistor values may need adjustment to suit your particular crosshair illuminator. Values shown work for Celestron.
Note 4 on sheet 1 - This resistor value is selected to match the declination and right ascension rates. The value depends on your dec motor and is specified for the Orion P/N 3903.
3.287671 MHz crystal parallel, 20 pF ± .005% non-oven HC33/U
cost: $6.25 U.S., including shipping
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Hammond transformers and cases from:
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* * *
A careful observer may be able to see Mercury this month in the early morning sky. Greatest elongation occurs on January 3, at which time it will be most visible, but the placement is not favourable for arctic inhabitants such as ourselves. Nevertheless, watch for it until about the 19th, at which time the almost-new moon appears near Mercury.
Also in the morning sky is Saturn, rising somewhat earlier than Mercury.
The moon is near Saturn on the morning of the 16th.
The telescopic planets Uranus and Neptune will lie between Mercury and Saturn. The moon will appear near them on the 17th and 18th.
In the evening sky, Venus will be very prominent.
Mars, much dimmer, will be near Venus towards the end of the month.
Also, the moon will be near both these planets on the evening of the 24th.
The appearance of the moon near the morning and evening groupings of the planets can provide some interesting photographic oportunities, especially by inclusion of some terrestrial landmark as a point of reference.
-1 8 -A S T R O NOTES
c/o H e r z b e r g
I n s t i t u t e of A s t r o p h y s i c s
Nat i onal R e s e a r c h C o u n c i l of C a n a d a
10 0 S u s s e x Drive
O t t a wa C a n a d a
K1A 0 R 6
NATIONAL SECRATARY RASC
136 DUPONT S T.