AstroNotes 1981 February Vol: 20 issue 02



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FEBISSN 0048-8682
The Newsletter M agazine of the Ottawa Centre of the RASC
Vol. 20, No. 2
$5.00 a year
February, 1981
Rolf M eier......4-A Arnold Dr
C. R. M olson....2029 Garfield
Barry M atthews...2237 Iris St.
I want more articles, especially from the
Brian Burke
There will be a star night at the Indian River
Observatory on either Friday, February 27, or Saturday,
February 28. I have not noticed many new members at IRO
in recent months, and it may be due to a lack of trans­
portation. Therefore, we will meet at the Carlingwood
shopping centre. This will be the first time in close to
two years that this arrangement has been attempted. The
success of this method of providing rides depends on both
those of you in need of a ride and those of you who can give
one showing up at Carlingwood. W e will leave Carlingwood
at 19:30. W e will meet at the entrance to the shopping
centre where there is a Boots Drug Store just inside. If
you need a ride give me a call at 521-8856 . I would like
to know how many cars may be needed. If you can help with
transportation please let me know.
Do not hesitate to bring out your telescope. Both
Jupiter and Saturn will be well-placed for observation all
night. Additional telescopes at star nights is always
appreciated because it reduces the demand on the 16-inch.
I t also allows members the opportunity to become familiar
with the different sizes and designs of telescores. I
h ope to see all of you at IRO at the end of the month.Brian Burke opened his first meeting as chairman at
8 :20 pm. Of the 38 people attending, 7 were non-members.
Following an introduction of this year’s coordinators
was a reminder that Astronotes costs money to ma il and an
effort to pick them up when attending meetings would be
appreciated. The December 12 star night saw only 4 members
entertaining many Almonte visitors with clear, cold skies
and rotten hot chocolate. Transportation costs to this
year’s General Assembly can be attained from Brian Burke
after the meetings.
Robin M olson, representing the IRO Committee, reported
an exhausted money supply for road clearing, so be prepared
to walk a little.
Jon Buchanan presented the new 340 (US) AAVSO Star
Atlas that is based on variable stars. The charts have
the magnitudes of some stars labled for comparison.
Fred Lossing gave the main talk of the evening, and
by using his portable Earth-M oon system he demonstrated
various aspects of the moon’s orbit. There were a couple of
interesting things mentioned. One was that eclipses occur
in a series of 3, 2 solar with 1 lunar in the middle. The
total number of eclipses possible in one year is 7.
Another was that there is a wobble in the moon's orbit due
to the fact that the sun’s attraction is 2.2 times greater
than the earth's. This wobble induces an 18.5-year cycle
called a Saros, during which almost identical eclipses of
the sun and moon are periodically repeated.
Frank Roy followed, presenting his sidereal clock.
This device, now in use at IRC, has a display which enables
users to compare standard and sidereal time. It is useful
in radio astronomy because sources are located by sidereal
Next came the "constellation quiz", featuring Taurus,
Auriga, Perseus, and many more, including a colorful shot
of the Orion Nebula. Frank took the slides w ith an f/2.9
24-mm lens. Also mentioned was the Quadrantid meteor
shower which took place that night, with requests for in­
terested people.
Dave Fedosiewich gave the comet review update. Comets
Encke and Tuttle are now too far south to be observed.
Stephan-O terna was fading to magnitude 9.5 in Auriga.
Comet Bradfield 1980s is anticipated in the next few
Paul M ortfield, with a few hints for those in search
of dew caps, was next. Using an empty ice cream container
or a Javex bottle dots a great job.Brian Burke reported a bad year ahead for occultations
of any kind.
Any good, grazing occultations of asteroids
will be announced at meetings.
For those using IRO a reminder to not totally fill
the water containers as there have been problems with the
heating usnits and the water could freeze, breaking the
containers. If you discover or have any trouble with the
heating please call Barry M atthews or Robin Molson.
The meeting was adjourned at 9:57 pm.
# # # # # # ###
Susan Argue
A coordinator’s meeting was held on January 11, 1981
at the home of Dave Fedosiewich.
Discussed were the responsibilities and future plans
of the coordinators. We may be seeing more of them at
star nights, Observer’s Group meetings giving talks, and
in Astronotes discussing various aspects of their respec­
tive coordinatorships.
Astronotes is to be used to suggest projects, report
observations and discuss theory. Any member is welcome to
submit articles. A survey will be taken at one of the up­
coming meetings to discover the interests and wishes of
present members.
There was a suggestion that the topics of workshops
allow for regular members as well as new members. The
purpose of star nights for the public and for members was
discussed and as a follow-up from the above suggestion
there will be a star night at IPO for members. The trans­
portation, which is the secon-greatest deterrent (the first
being the weather), will hopefully be organized.
Activities to recruit members and to raise money were
discussed, as well as the Centre display and papers for
this year's General Assembly.
# # # # #
# # # #
Articles for the March issue of Astronotes are
due by February 20.
# # # # # # # # #A meeting of Council was held on December 15 at
the NRC on Sussex Drive. The meeting affirmed the
following committees for 1981:
Astronotes Editorial Committee
Awards Committee
Observatory Committee
Nominating Committee
Program Committee
Publicity Committee
Also, the Editor of Astronotes and the Auditor were
re-affirmed. A new Committee, the Finance Advisory
Committee, was established. This Committee’s function is
to keep under review the finances of the Ottawa Centre and
to make recommendations to Council respecting financial
management policy.
Council also decided that Astronotes should accept
a limited amount of advertising of an astronomical
nature in order to raise money.
# # # # # # # # #
Due to the severe winter conditions this year, and
the state of the Centre’s finances, it has been necessary
to suspend snow-clearing operations at the observatory
for the time being. If the situation improves, snow
clearing will be re-established. In the meantime, members
who use the facilities are asked to ensure that all
vehicles are parked so as not to obstruct access to the
farm and its buildings. Keyholders should ensure that
this condition is met at all times.
# # # # # # # # #
Although Hailey’s Comet will not return until 1986,
astronomers expect to be able to pick up its faint image
in the fall of 1983.
# # # # # # # # #The predictions of lunar grazing occultations in the
first half of this year- arrived early last month. I have
selected 3 out of the 9 grazes listed that will be worth
observing. The date, time, and classification of each
graze is:
Graze 1:
Graze 2:
Graze 3:
April 9; 21:12 EST; marginal
April 10; 22:09 E ST; marginal
June 8; 00:08 E ST; favourable
Normally, an attempt would not be made to observe a
marginal graze but the first two are so close the effort
would be worth it. "How close are they?” you ask. W ell,
they are so close that if you set up your telescope in
your back yard you might observe both grazes! The limit
line of the first graze crosses at the intersection of
Baseline Road and W oodroffe Avenue. The second crosses
Bank Street at Landsdowne Park. Both limit lines run from
the northwest to the southeast. However, keep in mind
that grazes 1 and 2 are classified as marginal, which means
that they will be very difficult to observe. The magni­
tudes of the stars involved are 8.1 and 7.8 respectively.
The best location for graze 1 appears to be just out­
side Ottawa on either Highway 16 or 19 near Uplands Airport.
Choosing a location for graze 2 is somewhat more difficult.
About 2 km south of W alkley Road along Conroy Road appears
to be the best site.
The site for graze 3 is about 20 km north of Bucking­
ham, Quebec. However, the star’s magnitude is 7.1, and
the moon will only be 10° above the horizon. The moon’s
low altitude may make this graze impossible to observe,
but a check of a topographic man will be required
before I
make a decision.
A new centre is now receiving lunar occultation ob­
servations. It is the IOC (no, not the International
Olympic Committee, but the International Occultation
Centre) in Tokyo, Japan.
I should mention that I w ill give more details about
the plans to observe each graze at a later date. Until
then, do not forget to observe total lunar occultations.
# #
# #
# #
Dr. Allan Cooke
The recent fly-by of Saturn by the Voyager I spacecraft produced some
of the best observations of the planet yet obtained.
The photographs
of the planet, its rings and moons, revealed details beyond the reach
of the largest Earthbound telescopes.
The speaker will describe the
new data, show a selection of the photographic material, and discuss
how the Voyager mission has changed our ideas concerning the Saturn
Monday, February 16, 1981
8:15 p.m.
The March meeting will be held at 8:15 p.m. on Wednesday, March 11th.
The speaker will be Dr. Paul Feldman of the Herzberg Institute and the
topic will be "The Extinction of the Dinosaurs”.
All meetings are held in the Auditorium, National Research Council,
100 Sussex Drive, Ottawa.
K. F. Tapping
Admission is free, all are welcome.
C. R. Molson
225-3082In the January issue of Occultation Newsletter, a
listing of occultations by asteroids for this year appears.
There are 4 events that may be visible in the Ottawa area
and they are as follows:
April 4; 5:03 EST; 91 Aegina
June 4; 23:02 EDT; 129 Antigone
August 19; 20:09 EDT; 409 Aspasia
August 25; 23:33 EDT; 105 Artemis
The stars that will be occulted are all brighter than
9th magnitude. Event 1 is the most favourable, but it
occurs 30 minutes before sunrise. The most interesting
occultation could be event 2. However, depending upon
which asteroidal ephemeride is used
for Antigone,
occultation path could be 1060 km north of Ottawa or
1000 km south. Since we are about midway between the 2
predictions, it will be worth the effort to observe it.
The positions of the last 2 events are rather uncertain
at this time. Event 3 occurs just after sunset and a
northwest shift of its path would be required to be
visible in our area. A large shift to the west is needed
for event 4 to be visible in the Ottawa region.
I will provide additional information for each
occultation in Astronotes the month preceding the event.
I should be receiving this month more detailed maps of
the paths of visibility and I will include these along
with the finder charts in later issues of Astronotes.
Asteroidal occultation observations should be recorded
using a tape recorder to record your voice and the CHU
time signal. The tape can then be analyzed after the event
using a stop watch to obtain accurate times.
If you are interested in observing occultations by
asteroids let me know so that I will know who to contact
if I receive updates on any of the events. There is also
the possibility that I may organize expeditions to
observe asteroidal occultations. These would be similar to
the expeditions for lunar grazes but in most cases the
observing locations would be near Ottawa.
# # # # # # # # #The 1981 Quadrantids were observed at Springhill
M eteor Observatory, 25 miles south of Ottawa, by several
members of the Observer's Group. Thanks go to Mr. Lauzon,
for a group of us departed from NRC on Sussex Drive on
Friday, January 2, for the half-bour drive to Springhill.
This was the night of the Observer’s Group meeting.
According to Peter Millman of NRC , rates should have
reached a maximum of 40 per hour at 09:00 E ST on the 3rd.
W e started observing at 12:00 midnight and observed on and
off until we left at 04:00. At the beginning, the rates
were about 10 per hour, but by the time we left they had
increased to 20 per hour per observer. It was difficult to
observe for more than an hour at a time because of the
extreme cold of -35°C. In these cold temperatures the
heated coffins proved insufficient.
A few very bright Quadrantids were seen by some of
us and also by the video equipment which Peter Millman was
using to record the shower. Most of the meteors seen were
dim and observed in the last hour. Also, quite a few
meteors were picked up by the radar at the site. According
to Peter Millman, he had not seen it so clear for the
maximum of the shower for the last 20 years. Of the 10
people who came up, only 3 did any real observing.
# # # # # # #
Frank Roy
A penumbral eclipse of the moon occured at 02:50 EST
on the morning of January 20, 1981. I had set my alarm
clock to 2:30 but setting up when it rang was no easy
task. But alter 20 minutes I finally decided to get up.
I went outside to see the eclipse . It was very clear.
The moon was half darkened, but the dark side was still
quite light. Jupiter and Saturn were close together
that night. W hat surprised me was that they had moved
apart in the last 9 days. There are a series of Jupiter-
Saturn conjunctions this year, the latest occuring on
January 14. The next eclipse of the moon, a partial one,
is visible from North America on July 15. The January 20
eclipse was penumbral. So, the next
time the earth’s
shadow hides the moon, make sure you are not hidden.
# #
# # #
The recent cold spell was accompanied by very clear
skies, so it is a shame that observing was so uncomfortable.
Here are some hints on coping with the cold:
Hot Suit
The best kinds are surplus space suits. You could try
getting one from NASA, or one of the movie studios. If you
can’t get a space suit, you will
have to make one. Shoppi
bags from grocery stores are good for helmets. Don’t
forget to cut a hole in the faceplate that you can see out
of. Most space suits block radiation, so unless you do
this, the light from your telescope will be very faint. If
you cut a hole in the faceplate, don't use your space suitTo reduce cost, and to avoid the distortion caused
by glass, this heated observatory is made of Saran W rap.
This also allows a lightweight structure to be built.
Since Saran W rap is only about 30 cm wide, you will have
to build a framework for small pieces. To keep the
structure from falling down, maintain a positive air
pressure inside. This can be done with a vacuum cleaner
exhaust, or a hair dryer. The latter will save energy,
because you then don’t need a heater in the observatory.
Don’t use a car exhaust, because these gases are
poisonous.This is the ultimate in comfort, because it enables
you to do your observing indoors while the equipment stays
outside. You need 2 things: 1) a television camera and
2) a remote control for your telescope. You can buy the
camera in any store that sells video recorders. If you
need one, you should also buy a television set. For a re­
mote control, get one with a lot of channels. Don’t for­
get that you have to adjust RA, Dec, focus, change eye­
pieces, and move stuff around, all by remote control.
Check with your neighbours to make sure you are not opening
their garage doors. Note:
If your backyard has too much
light pollution, you can build a remote-controlled obser­
vatory far away, say on a mountain.TO
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