AstroNotes 1983 December Vol: 22 issue 11



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The Newsletter Magazine of the Ottawa Centre of the RASC
Vol. 22, No. 11 $5.00 a year December 1983

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



B.L. Matthews

As many of you know, I have been interested in antique instruments (primarily telescopes) and old astronomical books. Usually the instruments are out of my price range and I have to settle for pictures, drawings, or verbal accounts. Obtaining this information is a hit and miss situation at any time.

When looking through the latest issue of Nova Notes, the Halifax Centre's newsletter, I was pleased to read that a new society has been formed, namely the Scientific Instrument Society. In April of this year, the new society was formed in London, England with Gerard Turner of the Museum for the History of Science, in Oxford, as the founding Chairman. At this time, the society has less than 100 members and anyone interested in membership should write to the Secretary, Carole Scott, c/o National Maritime Museum, Greenwich, England. The first issue of the S.I.S. Journal is expected to go to press early this fall.

Membership for S.I.S. is about $17.00.

Thanks to Randall Brooks, of the Halifax Centre, for bringing this new Society to my attention.

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Articles for the January issue of Astronotes are due by December 16.
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David Lauzon

The following few months appear to be good months for meteor observing. During December, there are two major showers, the Ursids and the Geminids. January's major stream is the Quadrantids.

Unfortunately, this year the Ursids occur too close to the full moon and will not be observed, but this need not upset the meteor seeker in all of us. The Geminids and Quadrantids will be observed, weather permitting.

The following table is a summary of data about each shower.

shower name Geminids
date of max Dec 14
time of max 13:00
moon  01:03 rise
hourly rate 50
speed km/sec 35

shower name Quadrantids
date of max Jan 3
time of max 21:00  
moon new moon  
hourly rate 40
speed km/sec 41
The Geminids

This shower is easily observable in the northern hemisphere. The radiant lies close to the star Castor, or more precisely at R.A. 7h 32m Dec +32°.

One thing in particular about this shower is that it is young, but not associated with any known comet. The radiant is sharply defined, having an area of about 0.2° in size. Records of this shower go back no more than 100 years.

Geminid meteors are bright, and slow-moving. There is also a large distribution of fireballs and faint meteors.

The constellation of Gemini rises late in the evening and is in the sky until dawn. The duration of the Geminids to 1/4 maximum is about a week, centred on December 14.

The Quadrantids

This brief shower is one of the hardest to observe for the following reasons:
1) The radiant is close to the sun, making observations limited to after midnight.
2) The duration to 1/4 strength is very short (1.1 days).
3) In early January, it is usually very cold (brrr!), so therefore be prepared and dress for the weather.

I remember my first "meteor experience" in January of 1981. We were observing the Quadrantids at the Springhill Meteor Observatory, and it was rather cool (-60°C with the wind chill factor). From my personal experience with this shower, if sky conditions are good, it is worth suffering.

A highlight of this shower is that there seems to be an uneven distribution of magnitudes in the meteors. They resemble the Geminids, and have a velocity of 41 km/sec. A characteristic colour of Quadrantids is the "electric blue."

One question you may ask is "What constellation is Quadrans Muralis?" Well, don't bother looking on your star atlas for it because you won't find it. This constellation was abolished and replaced by our conventional groups called Draco, Bootes, and Hercules. The radiant lies at R.A. 15h 28m Dec +50°, making it circumpolar at our latitude, but the radiant isn't in a good position until about 2 am.

This is a brief description of these two meteor showers, but to really get to know them, you must observe these showers. Meteor sessions for the Geminids are being planned for December 9/10 and 10/11. A meteor session for the Quadrantids is planned for the night of January 3/4.

If you are interested in joining the meteor squad, please contact me at the meeting or call at 743-7962 so we can plan a meeting place and drives.

The accompanying map shows the radiant of these two showers, and reference stars.

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Is anyone out there interested in getting started on observing variable stars? It is great entertainment, and a telescope is not necessary, you know. Or, is anyone out there observing variable stars on their own? Then it's time to come out of the closet! If your answer is "yes" to either of the above, I would appreciate hearing from you. Any information you can give me would help in preparing a variable star program for the new year. Please see me at an Observer's Group meeting, or feel free to give me a call at 829-7514.

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This annual event had good clear skies on two nights, October 8/9 and 9/10. The first night was preceded by the 3rd annual picnic. A handful of members enjoyed hot dogs, frisby throwing, and boomerang throwing, interrupted only by a large group of people walking through the woods toward the Mill of Kintail. Sandy Thuesen's new telescope was toasted as well.

Skies were clear and dark. About 30 members and friends came to observe the wonderful deep sky objects on view, and at least 12 telescopes were brought out, as well as binoculars and the observatory instruments. There were many large telescopes, including a 17.5-inch, 13-inch, a C-11, at least 2 10-inch, and many C-8's. This was over and above the Observatory's 16-inch, of course. And all enjoyed looking at the many objects the sky made available on the two nights. Even though it was cool, the observing was excellent.

Let's hope for similar good conditions for next year.



Here are the answers to last month's quiz:

1) Venus
2) January 4
3) a jet
4) Clyde Tombaugh
5) 1000
6) M 1
7) "Little Green Men"
8) Hydra
9) Vulcan
10) artificial earth satellites

And some more questions:

1) How many planetary satellites are currently known to exist in the solar system?
2) Where is Solis Lacus?
3) Which element is named after the sun?
4) Which planet has the Van Allen Belts?
3) What was rare during the Maunder Minimum?
6) Which observatory discovered pulsars?
7) What number together with red shift is used to calculate the distance to galaxies?
8) What stars are used to calculate the distance to the nearest galaxies?
9) How far can the unaided human eye see?
10) Which galaxy has the greatest supernova rate in recent times?

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Attendance at this meeting was 31.

Chairman Rolf Meier opened with some announcements. He reminded members of the upcoming dinner meeting, and Rob McCallum gave more details and tickets. Rolf described the recent picnic and Deep Sky Weekend. He encouraged members to submit their observations for the Variable Star Award and the Observer of the Year Award. Memberships and handbooks were also available.
Gary Susick then introduced some observing speakers.

Brian Burke was up first with a video tape of occultations, including a very interesting grazing occultation. An eclipse was also included. Brian hopes to recruit a camera and recorder for the November 28 occultation at IRO, although Brian's cinematography will hopefully be better than the tape shown.

Malcolm Lambourne was up to encourage members to join his telescope-making workshops. Sandy Thuesen was able to make use of the workshops to build a telescope, and it is hoped other members can do the same.

Simon Tsang showed the group some slides he had taken recently with a 135-mm f/1.8 lens. The nebulosity in his photographs showed up very well, with rather short exposure times.

Rolf Meier then gave a talk about the 1984 Observer's Handbook. He described some new features, and went over some observing highlights for 1984. He also described some differences between the current handbook and that of previous years, going back to 1968. Some interesting statistics were revealed.

Finally, Rolf conducted elections for coordinators for the coming year. The results are as follows:

Chairman: Gary Susick
Vice-Chairman: Malcolm Lambourne
Comets, Novae, Asteroids: Dave Fedosiewich
Meteors: Dave Lauzon
Radio Astronomy: Frank Roy
Occultations: Brian Burke
Lunar and Planetary: Rolf Meier
Solar: Linda Warren
Deep Sky: Gary Susick
Instrumentation: Malcolm Lambourne
Variable Stars: Sandy Thuesen
Recorder: Dave Lauzon
Astrophotography: Bill Donaldson

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Unknown to them at the time of this writing, the winner of the Observer of the Year Award is Sandy Thuesen and the winner of the Merit Award is Robin Molson. The awards are presented at the Dinner Meeting.