AstroNotes 1982 March Vol: 21 issue 03

Pages: 

14

Download PDF version: 

ASTRONOTES ISSN 0048-8682
The Newsletter Magazine of the Ottawa Centre of the RASC
Vol. 21, No. 3 $5.00 a year March, 1982
Editor....... Rolf Meier....... 4-A Arnold Dr......820-5784
Addresses....Art Fraser....... 11-860 Cahill Dr.. .737-4110
Circulation...Barry Matthews... 2237 Iris St....... 225-6600
OBSERVER'S GRO UP MEETING - JANUARY 8 Cave Fedosiewich
Vice-Chairman Rob McCallum opened the meeting of 61
people with an invitation to present members to renew their
memberships. With the increase in the postal rates again
(to A cents), Rob urged everyone in attendance to pick up
friends' copies of Astronotes to reduce the costs. Also,
anyone who has not renewed their membership fee will not
receive Astronotes until they do so.
Our solar coordinator, Rob Dick, was up next with some
news about a flare that had taken place the day before the
meeting. Rob's correlations of solar observations at
optical and radio wavelengths up to mid-January showed
average activity on the sun over the past few months. Rob
also displayed his first attempts at photography in H-alpha
light using the Daystar filter mounted to a 6-inch
refractor. Several filaments were apparent on the disc,
and as Rob noted, were always in the immediate vicinity of
a sunspot group. He also requested some white-light
observations to compare with his H-alpha observations and
Ken Tapping's radio observations.
For those with little bravery for the cold in Canada's
great white north, Jack Horwood had the answer if your
interest was in meteors. First of all, Jack described his
"meteor receiver", which consists of an fm receiver
connected to an 11-element Yagi antenna. A chart recorder
and tape deck were hooked to the receiver's output to
produce a hard copy of his observations and a taping for
later analysis. Jack then picked a blank spot on the fm
band at 89.3 MHz and listened. Every few minutes, a
station would fight its way through the noise and remain
for a second or two. Jack explained that this phenomenon
was due to a distant radio station's signal bouncing off a
meteor's ionized trail, sometimes from a station's as
-1 -distant as 1000 miles. As the peak of the Quadrantid
shower on January 3rd approached, Jack recorded a marked
increase in activity on the frequency he was monitoring,
and several chart recordings were displayed and showed some
convincing results.
With a more physical analysis of meteors in general,
our meteor coordinator Dave Lauzon presented a talk dealing
with the origin and major characteristics of meteors and
meteoroid streams. He explained how these streams, in
elliptical orbits around the sun, are built up from the
continuous passage of periodic comets as they scatter
debris from their nuclei. Dave also explained the reason
behind the great Leonid showers which take place every 33
years; this is due to the remnants of a comet's nucleus
passing directly through the earth's orbital plane. John
Hache broke in to tell the group about a bright meteor he
had observed in late December, which took a rather peculiar
turn as it passed through Orion. A loose discussion
ensued.
Robin Molson informed us that there will be no plowing
of the road past the farmer's house leading to the
observatory. Visitors are asked to park their cars in the
parking area near the house, and not in the driveway, since
this w ould present a safety risk in case of fire or
accident. If parking is not available in this area, then
your next best bet is the highway at the entrance to the
driveway, since there is usually plenty of room on the
shoulders.
A final announcement was supplied by Peter MacKinnon,
who has large photographic plates and emulsion available
for anyone interested.
Chairman McCallum adjourned the meeting at 9:59 pm
EST.
* * *
OBSERVER'S GROUP MEETING - FEBRUARY 5 Dave Fedosiewich
Chairman R olf Meier opened the meeting at 8 :14 pm with
51 people in attendance, 36 of whom were members. Rolf
gave a description of the Observer's Group to initiate
prospective members to the Society.
Brian Burke was up to tell the group about hopefull
lunar grazes for 1982. Of special interest is a graze that
passes right through Ottawa, and across Landsdowne Park!
Tickets for this and other events will be on sale when
-2 -Brian updates us later on in the year.
Philip Forsythe, our lunar and planetary coordinator,
gave us a resume of the positions of the planets for
February. Philip stressed that he would like to see
amateurs observe the "old favourites"; these are Venus,
Mars, Jupiter, and Saturn. He would like to see same
drawings of Jupiter and its moons as it will be at
opposition this spring.
Jamie Black gave a small talk on heliocentric
longitudes, which has to do with the position of the
planets as seen by an observer in the sun. Jamie explained
this system of identifying the positions of the planets,
and their non-importance to amateur astronomers.
Cave Fedosiewich (yours truly) presented some
information and statistics on the scarcity of observable
comets in 1981. This year looks more promising already,
with 3 periodic somets returning to perihelion. The
recovery of Halley's Comet is also a possibility by late
this year.
Gary Susick had so me slides courtesy of Celestron
International. Included in the set were shots of the
Horsehead Nebula, the Double Cluster, M 57 (the Ring
Nebula), M 42, the Rosette Nebula, and others, taken
through Celestron 'scopes or Celestron Schmidt cameras.
Our solar coordinator, Rob Dick, showed us his plot of
solar activity containing all recorded data up to the
beginning of February. He commented on several displays of
aurora for late January and early February that correlate
quite closely with the increase in sunspots and flares over
the same period of time. Rob also displayed his new
H-alpha filter, made in California, but modified to
withstand the grueling winter in the great white north.
Dave Lauzon displayed some slides of recent aurora
activity, all being photographed from within Ottawa. He
also displayed some prints taken with Tri-X pan film using
short exposures.
Rolf closed the meeting at 10:10 pm.
* * *
SOLAR ACTIVITY Rob Dick
The accompanying plots show the activity of the sun at
435 MHz for the last 5 months. The crosses just above the
abscissa indicate aurora observations that have been
reported. The limited time the sun is "visible" in Ken
-3 -Tapping's radio telescope restricts observations to less
than a few hours centred on mid-day. This prevented him
from picking up a flare which was observed visually and
photographically in H-alpha on February 10, 1982.
At 09:12:20 EST, a light meandering line was noticed
slightly west of a group of sunspots located near the
centre of the disc. It increased in brightness for about
10 minute. This was the first time I had seen a flare in
progress! Figure 1 shows the shape of the flare. A
portion of the flare was resolved into two parallel
filaments. Photographs of the flare did not show this twin
nature very well but several knots along the length were
resolved photographically.
At the same time this flare was observed another flare
was observed on the west limb extending about 2° along the
limb. It appeared to be composed of many bright, large
spicules jutting up from the surface.
Meanwhile, another flare was erupting on the east
limb. When the observing session began at 09:12 EST, it
was seen as a bump on the limb. Over the next 5 to 10
minutes it rose up and slowly faded from view over the next
10 minutes (see the sketches in figure 2). This fading was
perhaps due to the Doppler shift of the wavelength towards
the red and out of the passband of my H-alpha filter.
Three nights later (February 13/14), Rolf Meier noticed an
aurora over 2/10 of the sky.
I would appreciate hearing from other observers that
have been watching for aurora or have photographed a
display. When photographs of the sun are shown at
meetings, white light drawings or photographs of the solar
disc would help orient the audience. If you have pictures
of aurora or the sun, let me know, and bring them to the
Observer's Group meetings. I would like to see them. I am
most interested in detail drawings of the sunspot groups,
and how they evolve.
* * *
STOP PRESS! A large aurora display was observed on the
night of February 21/22 beginning shortly after sunset. At
times the aurora covered 7/10 of the sky, extending into
Orion. Green rays and a red glow were noted. A fine
corona developed. Later on the aurora pulsated. -Ed.
* * *
-4 -F I G U R E 1 - F L A R E S O F F EB 10/82
N
D E TAIL O F CENTRAL FLARE
-5 -Secretary: President:
C. R. Molson
225-3082
996-0845
ROYAL ASTRONOMICAL SOCIETY OF CANADA
Ottawa Centre - Lecture Meetings
K. F. Tapping
593-6060
684-1186
Wednesday, March 10
Dr. Paul Feldman, Herzberg Institute of Astrophysics
The Jupiter (Non-) Effect
Eight years ago two ex-Cambridge University theoretical astronomers
revived the notion that planetary tides generate sunspots, but this
time with a new (and odd) twist; they claimed that sunspots,
through a series of complex and unproven connections, trigger major
earthquakes. John Gribbin and Stephen Plagemann’s book "The Jupiter
Effect has provoked more public concern than any other astronomically related issue of the last decade (according to the Griffith
Planetarium Observer). On 10 March 1982 the heliocentric sector
containing the nine planets of our solar system will be at a
relative minimum of 95 (the so-called "Superconjunction of 1982"),
and this has led to doomsday predictions by various Jupiter-Effect
cults. Spend this "special" evening with an astronomer who will
set your mind at ease; there is no reason to believe that the
supposed line-up of the planets poses any threat to humanity.
Wednesday, March 24 , 8:15 p .m.
A Film Show: "Beyond the Milky Way"
April: Date to be Announced
Speaker: Dr. Henry Matthews, Herzberg Institute of Astrophysics
Title: "Galactic Radio Astronomy"
Speaker:
Title:
May: Date to be Announced
Speaker: Dr. Don Smelley
Title: "The Solar Corona"
All meetings are held in the Auditorium of the National Research Council, 100 Sussex
Drive. The starting time is 8:15 p.m.
Admission is free, and an invitation is extended to members and non-members.S o l a r Ac t iv it y
6FIG U R E 2 .
* * *
END OF MARCH LUNAR GRAZE Brian Burke
There will be a lunar grazing occultation on Sunday,
March 28, visible from a location about 30 km north of
Ottawa. This graze is a few kilometers past the site of
last December's graze (expedition cancelled due to
snowstorm). The driving time is less than 30 minutes. The
key information for the graze is as follows:
date: March 28
time: 20:22 EST
star: X 4666
magnitude: 8.1
limb: north, bright
moon: 16% sunlit
type: marginal
We will meet in the NRC parking lot at 18:45. If you
would like to participate in this graze expedition, give me
a call at 521-8856. This will be a very difficult graze to
observe since the star is 8th magnitude and it grazes on
the bright limb of the moon. Anyone willing to lend
equipment such as telescopes, tape recorders, and CHU
receivers, please let me know.
* * *
- 7 -THE COMET REPORT Dav e Fedosiew ich
If one word could best describe cometary activity for
the year 1981, I would certainly pick the word "dead". Of
the 12 comets discovered or recovered in the past year, not
one has come within reach of an amateur telescope. Veteran
comet hunter Rolf Meier commented: "I guess things can't
get much worse that they've been in 1981. The way things
are going, we may have to rely on the periodic comets for a
while until this comet drought dies off."
With 3 fairly bright periodic comets due for
perihelion this year, things could start to pick up as
interest in these comets materializes. P/Grigg-Skjellerup
should become visible in early May at magnitude 11.4.
P/D'Arrest will follow at the beginning of August and
brighten in September to magnitude 10.5. The third oomet,
P/Churyumov-Gerasimenko, has not been observed since its
discovery passage in 1969, when it was found on a
photographic plate. With its apparition this year being an
extremely favourable one, the information acquired through
observations should permit better orbital elements to be
calculated, and a revised ephemeris should ensue.
The ephemerides for these comets are in the Observer's
Handbook 1982.
On a final note, this could be the year that Garnet
Halley is recovered. At the moment, a number of
astronomers have begun the search, including M.V.P.
astronomer Charles Kowal, who has been responsible for the
majority of recoveries for the past few years. Early this
year, the comet is predicted to be about magnitude 24 in
Canis Minor. With the development of new image-recording
techniques, chances are good that Comet Halley will be
found by December.
That's all for now.
* * *
CALCULATING SIDEREAL TIME Frank Roy
It is sometimes necessary to calculate local sidereal
time. Although there are several ways in which one can
achieve this goal, I found the method described in the
Observer's Handbook 1981 to be quick and straightforward.
In setting the digital sidereal clock I built for IRO ,
I found it necessary to calculate the local sidereal time
-8 -over the course of a few minutes. A program I wrote for my
HP 33E calculator now does this calculation in a few
seconds. Any HP programmable scientific calculator can run
this program.
line keystroke display remarks
00 f PRGM 00 clear program
01 STO 0 23 0 enter GST in h, m, s
02 R/S 74 run
03 STO 1 23 1 enter day of month, decimal
04 R/S 74 run
05 STO 2 23 2 enter time of day, decimal
06 R/S 74 run
07 STO 3 23 3 enter long. in dec. hrs.
08 RCL 0 24 0 after last entry, recall GST
09 g H 15 6 convert to decimal hours
10 STO 0 23 0 store new number
11 RCL 1 24 1 recall day of month
12 ENTER 31 move up stack to y register
13 73
14 0 0
15 6 6
16 5 5
17 7 7
18 X 61 multiply day of month
19 STO 1 23 1 store new number
20 RCL 2 24 2 recall time of day
21 ENTER 31 move up stack to y register
22 1 1
23 • 73
24 0 0
25 0 0
26 2 2
27 7 7
28 X 61 multiply time of day
29 RCL 0 24 0 recall hours
30 + 51 add to time of day
31 RCL 1 24 1 recall day of month
32 + 51 add to previous answer
33 RCL 3 24 3 recall longitude
34 - 41 subtract or add
35 g X 70 15 51 is result positive?
36 G TO 40 13 40 if yes go to 40
37 2 2
38 4 4
-9 -39 + 51 if no add 24
40 2 2 enter in x register
41 4 4 y register is last result
42 X-Y 21 exchange x for y
43 f X-Y 14 41 is answer smaller than 24?
44 G TO 46 13 46 if yes go to 46
45 - 41 if no subtract 24
46 f H.MS 14 6 convert to h, m, s
47 G TO 00 13 00 ready for new data
48 display will show LST in
49 hours, minutes, seconds with
the decimal point separating
the hours and minutes
This program does wo r k and the answer will always be
between 0 and 23h 59m 59s . In this calculation it is
important to know your longitude to the nearest few seconds
of arc if you want the answer to be accurate to a few
seconds of time.
Note that longitude is usually expressed in degrees,
but the calculation requires time.
Example: Calculate the local sidereal time for IRO on
January 8, 1982 at 20:00:00 EST.
Solution:
EST to UT = 01h January 9, 1982
longitude = 76° 15' 38.9" = 5h 05m 02.6s
d = 8
t = 01
GST = 06h 37m 18s (from Handbook)
Enter program and return to line 00. The answer on
the display is 3.0559, or 3h 05m 59s .
* * *
-10-c/o Herzberg Institute of Astrophysics
National Research Council of Canada
100 Sussex Drive
Ottawa Canada
K 1A 0R6
MS. rosemary freeman cast
NATIONAL SECRETARY
THE ROYAL ASTRON. SOC. OF CAN.
124 MERTON STREET
TORONTO, ONTARIO M4S 2Z