AstroNotes 1982 November Vol: 21 issue 11

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ASTRONOTES ISSN 0048-8682
The Newsletter Magazine of the Ottawa Centre of the RASC
Vol. 21, No. 10 $5.00 a year November 1982
Editor....... Rolf Meier....... 4-A Arnold D r......820-5784
Addresses....Art Fraser....... 11-860 Cahill Dr...737-4110
Circulation...Barry Matthews...2237 Iris S t....... 225-6600
DEEP SKY WEEKEND
The 10th annual Deep Sky Weekend was held at the
Indian River Observatory on October 15/16/17 this year.
Friday night was clouded out, but on Saturday a cold front
passed through, and skies were very clear for the night.
There were a number of people at the observatory on
Saturday night to enjoy the sights.
There were both novice and experienced observers
present, so the telescope was used to observe a variety of
objects. We alternated between bright, obvious deep sky
objects and dimmer, more obscure, but challenging and
interesting objects.
There was also an aurora that night.
* * *
HALLEY'S comet seen
Many people are probably aware by now that Halley's
Comet has been seen for the first time since 1910. The
200-inch on Palomar Mountain was used, together with a CCD
sensor.
It will be a couple of years before this comet will be
visible in amateur telescopes.
* * *
-1-ANNUAL DINNER MEETING
When: Friday, November 26, 1982
Cash bar opens at 6 pm, dinner at 7 pm.
Where: Top of the Hill in the Skyline Hotel,
101 Lyon Street (between Queen and Albert)
Guest Speaker: Dr. K.H. Doetsch, National
Aeronautical Establishment
"Canadarm: A Canadian Success Story"
Details: Price of a dinner ticket will be $20.
Tickets will be available at the November
Observer's Group Meeting. Payment may also be made
by mailing a cheque or money order, payable to RASC,
Ottawa Centre, to:
RASC Ottawa Dinner Meeting
c/o Robert McCallum
1958 Lauder Dr.
Ottawa, Ont.
K2A 1B1
Please note that no tickets will be available at the
door. Contact one of the Dinner Committee members listed
below if your payment will not reach us at least 48 hours
before dinner.
Guests are welcome !
The Dinner Committee consists of:
Peter MacKinnon (chairman) 827-0934
Robert McCallum 729-9977
Robert Dick 224-5583
* * *
-2COMET CHURYUMOV-G ERASIMENKO Rolf Meier
I observed this comet on October 23/24 and again on
October 25/26.
On both nights it was near the nebula M 1, but
unfortunately I missed seeing it on the night of nearest
approach to M 1, which occured on the 24/25. It was in the
same low-power field on all three nights.
The comet was close to the 1 0 th magnitude which was
predicted by the handbook. I will brighten to 9.8 during
November.
This brings to 4 the number of comets I have seen this
year. The others were D'Arrest, Grigg-Skjellerup, and
Austin.
* * *
SOLAR Rob Dick
The sun is not dead, nor is your solar coordinator.
However, in Ken Tapping's absence I have been unable to
peer through the cloud of the last few months to sample
the sun's somewhat erratic pulse. But the limited
observations I have made suggest that there is still an
active hemisphere on the sun.
Around the beginning of October, there were several
sunspot groups visible on the disc when viewed by eyepiece
projection with my 4 1/4-inch RFT. In H-alpha light these
centres were not very interesting, at least not when I was
looking. I hope to have a photograph or two at the
November meeting.
Observers can expect several sunspot groups to be
visible around the first week of November, in time for you
to report to the Observer's Group. These will be reported
at the December meeting.
I have not received any aurora reports. If you have
seen some recent displays of aurora, give me a call. I now
have a telephone answering machine for your convenience.
My number is 224-5583.
* * *AURORA REPORT Rolf Meier
At our two observing sites there are logbooks, which
are used for, among other things, noting certain kinds of
observations. Most observers have gotten into the habit of
recording the occurence of an aurora if one is seen. I
have looked back over the last 5 months of entries in the
log at the Indian River Observatory, and extracted all the
aurora reports. The dates of their occurence is listed
below.
Since observers are usually present only part of the
night, it is possible that aurora occured at some other
time on nights it was not reported. Also, all visitors to
the observatory are not yet trained to record an aurora if
one is observed. Thus, the nights listed below are
probably a minimum for the number of aurora which actually
occured, since several may have gone unreported. On the
other hand, all the reported events are real, aurora being
very obvious from the dark skies of IRO .
The dates below are nights for which aurora was
reported. The period covered is May 26/27 to October 24/25
inclusive. During this time, the observatory was visited
on a total of 34 clear nights. Since there are 16 nights
for which aurora was reported, I would estimate that we had
aurora at least one out of every two nights during the past
summer.
The dates marked with (*) are those for which an
aurora was observed which was extensive enough to warrant a
detailed description in the logbook.
May 26/27
June 9/10
June 11/12
June 26/27
July 13/14 *
July 16/17
July 19/20
July 23/24
July 29/30
August 20/21
September 7/8 *
September 8/9
September 9/10
September 19/20
October 10/11
October 16/17FIREBALL SEEN Rolf Meier
I was at IRO on the morning of October 26, and I saw a
bright fireball while observing through the telescope.
The meteor was bright enough to light up the telescope
tube as I was looking through it. I looked in the sky, and
saw a brilliant fireball, magnitude aproximately -8. The
fireball went from Orion and down and left through Hydra.
The time was 4:46 EST. The fireball was blue-white, and
fragmented in the south south-east, in the direction of
Almonte.
* * *
IRORI - 4 YEARS AND STILL GOING STRONG Frank Roy
The IRORI was officially opened on October 28, 1978 by
Arthur Covington. Back then the receiver was operating at
160 MHz, with tremendous interference problems. Many
frequencies have been tried from 109 MHz to 242 MHz, but
232 MHz was finally chosen, being almost free of
interference.
Since the opening in 1978, the receiver has been
rebuilt 3 times and the dipole and phasing harness system
has been redone. Now the receiver produces textbook-like
fringes of the sun, Cas A, and Cyg A. Taurus A, Virgo A,
and Hercules A have more noise but are relatively clean.
Hercules A is the weakest source so far picked up with
IRORI.
The radiometer now has a noise floor of 80 jansky,
still a far cry from the 20 jansky derived from the
original calculations.
The receiver has a measured noise temperature of
300° K, so the source of our problems lies in the antennas,
particularly the combiners. Three of them are used on each
antenna to collect the power of the 8 individual dipoles in
phase. Work has already been done to rectify the situation
and if the plan goes ahead the new combiner system should
be installed in early spring.
The eventual goal of the project is to pick up a
quasar and a pulsar. The strongest quasar is 50 jansky at
our frequency. It is very possible that we achieve that
goal with a computer Dave Vincent and I have been
experimenting with and with the improvements of the
antennas.
I hope the next four years will be as successful as
the first four.
-5-CALENDAR OF COMING EVENTS
Friday, November 5
Monday, November 15
Wednesday, November 17
Friday, November 19
Friday, November 26
Wednesday, December 1
Friday, December 3
November Observer's Group meeting
new moon
Leonid meteor shower
Astronotes due date
Annual Dinner Meeting
full moon
December Observer's Group meeting
* * *
NEXT ISSUE OF ASTRONOTES THE 200TH
The December, 1982 issue of Astronotes will be the
200th issue. It is also the 20th anniversary issue, the
first one having come out in December, 1962.
Anybody out there have a complete set? That would be
quite a feat. Mine is fairly good, but it's very easy to
misplace a copy or two or more. But there's a lot of
history in our newsletter, covering the activities of our
centre over the last 20 years.
Articles for the December issue of Astronotes are due
by November 19.
* * *
I don't understand this cartoon. No, really,
dosen't seen to make sense. Any explanations?
It
B.C.
-6-ASTRO NOTES
c/ o Herzberg Institute of Astrophysics
National Research Council of Canada
100 Sussex Drive
Ottawa Canada
K 1A 0R6
TO:
MS. R O S E M A R Y F R E E M A N C A S T
N A T I O N A L S E C R E T A R Y
T H E R O Y A L ASTRON. SOC. OF CAN.
1 2 4 M E R T O N S T R E E T
T O R O N T O , O N T A R I O M4 S 2Z