AstroNotes 1981 August Vol: 20 issue 08

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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. 20, No. 8
$5.00 a year
August, 1981
Editor....... Rolf Meier...... 4-A Arnold D r ...... 820-5784
Addresses.... Art Fraser...... 11-860 Cahill D r .. .225-3082
Circulation...Barry Matthews...2237 Iris St...... 225-6600
OBSERVER’S GROUP MEETING - JULY 3
Linda Warren
Brian Burke brought the meeting to order at 8:15 pm.
This month's meeting had a smaller group than usual, with
32 regular members attending and 8 non-members.
Brian
advised
that
the
Edmonton
Centre
won
the
display
competition at the General Assembly in Victoria.
He also reminded us that there will be a public star
night on Friday July 24th, or Saturday, July 2 5 t
h
.
Robin Molson advised that he and Fred Lossing were
working on lining up the telescope and that if we were
using it to bear in mind that the setting is a little off.
Robin asked that members show a little more care in making
logbook entries.
Also, although help is appreciated,
consult the committee prior to making any significant
changes around or in the clubhouse.
Our solar coordinator, Rob Dick, then talked about the
activity of the sun during the past month, showing by way
of graphs what old Sol was doing.
Pictures and more
details are in last month's Astronotes.
He asked that
members report to him any observations they may have, ie
aurora, to confirm his own observations and record them by
comparison.
Frank Roy impressed the group with his excellent
photographs, among them the Ring Nebula and the Dumbell
Nebula, taken with the 16-inch at IRO . One of the slides
of Cygnus picked up the Veil Nebula.
The film was
hypersensitised Fujichrome 400.
Brian Burke,
acting for Barry Matthews as lunar
coordinator, gave us more information regarding the partial
eclipse of the moon, taking place on July 16/17.
-1-According to Brian's printout from IOTA, grazes are
not very good this year, with only 5 listed for this area.
One occultation will occur July 19th around 3 am, and you
could probably see it with a 4-inch telescope.
The meeting ended early at 9:15 pm.
* * *
DATE CHANGE FOR SEPTEMBER MEETING
Brian Burke
The date for the September Observer’s Group meeting
has been changed from the first to the second Friday of the
month, thus avoiding meeting just before the long weekend.
Therefore,
the
September meeting will be on Friday,
September 1 1 th, at the usual time and place
* * *
AUGUST STAR NIGHT FOR THE PUBLIC
Brian Burke
There will be another public star night at the Indian
River Observatory this month, on Friday the 21st or
Saturday the 22nd . I encourage members with telescopes to
bring them to IRO, since the public living in the Almonte
area will be invited, and the more telescopes the better.
If rides are needed we will meet at the Carlingwood
Shopping Centre at 20:00, but please call me if you need a
ride at 521-8856.
Try to let me know by the 19th of that
month if you need a ride.
I am looking forward to seeing
all of you at this month’s star night.
* * *
DEEP SKY WEEKEND
Since the full moon occurs near Thanksgiving this
year, which is the usual weekend for the Deep Sky Weekend,
it will be held instead on the weekend of October 2-3-4.
Although not a long weekend, the Friday and Saturday night
should provide plenty of dark night-time viewing in the
crisp, cool October air. Remember that you may camp at the
observatory site, but you must provide all your own gear
and food.
*
-
2 -
*
*Rolf Meier
THE PLANETS NEAR SUNSET
Many observers may have noticed that the planet Venus
has appeared in the evening sky. During the next few weeks
and through September, Venus will be accompanied by Jupiter
and Saturn,
and for a few days, the crescent moon.
Although the scene changes daily, I have tried to depict
the appearance of the evening sky on August 4 below.
It is interesting to photograph the movement of the
planets relative to each other and the background stars
over a period of weeks.
Try this when they are close
together.
You may even pick up the asteroid Vesta as it
wanders about in that area.
Since this takes place in the evening sky just after
sunset, one can expect a number of "UFO" reports, as people
confuse the collection of bright planets for something
else, especially when sunlight glints off jetliners which
often appear in the direction of the setting sun.
-3--8--7-By the time you read this, the annual Stellafane
convention will have taken place.
Held each year near
Springfield, Vermont, it is an amateur telescope making
convention.
This year it took place on August 1.
There
are usually some telescope entries from Ottawa Centre
members, and this year is no exception.
There will be a
complete report in the next issue of Astronotes.
* * *
SIDEREAL TIME BASE
Frank Roy
Sidereal time gains on solar time by 3 minutes and 56
seconds per day, or 2 hours per month. This corresponds to
the angle the earth travels in its orbit in one year, and
in that time the stars will have gone all the way around
the sky.
Any clock that gains 3 minutes and 56 seconds a day on
solar time will keep sidereal time.
The circuits on the pages 7 and 8 will keep a clock on
sidereal time if it is desigend to run on 60 Hz or 50 Hz
(there are two separate circuits).
The IC’s are all CMOS,
so be careful of static.
The chip I had difficulty
obtaining was the CD 4059 AE (RCA).
Any RCA distributor
will order it for you (ie, Hamilton Avnet) with delivery
times anywhere from 1 to 5 weeks.
It costs about $10.
The supply voltage on the IC's must not exceed 18
volts, and should be regulated if possible.
The power
supply is not shown in the schematics.
For best accuracy, a frequency counter with 8 digits
should be used to set the crystal oscillator, and it should
be adjusted periodically during the first few days of
operation.
An oven may be used for greater stability.
Although not shown on the schematic, all unused CMOS
inputs should be tied to a supply rail.
References
1.
2.
3.
Observer’s Handbook 1981
Motorola CMOS Data, 1978
RCA COS/MOS Integrated Circuits, 1978
*
-4-
*
*AS TR O NOTES
TO
CAST
MS. ROSEMARY FREEMAN
NATIONAL SECRETARY
THE ROYAL ASTRON. SOC. OF CAN.
124 MERTON STREET
TORONTO, ONTARIO
M4 S 2 Z 2