AstroNotes October 1972

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AstroNotes

The Newsletter of the Ottawa Centre, RASC

Vol. 11, No. 8 - October, 1972

Editors
Addresses!
Circulation:
A S T R O N O T E S
$2.00 a year
Tom Tothill
Mary Grey
Ted Bean
22 Delong Drive, K1J 7E6
Dom. Observatory, 994-5474
399 McLeod Street, K2P 1A5
EDITORIAL
Mariner 9 pictures of Mars, published this summer,
reveal an astonishing variety of features not hitherto
suspected. Chief among these is the gigantic chasm that
runs for about 90 degrees of longitude roughly along the
parallel of 10 degrees south latitude. This identifies
with the edge of the dark area on visual naps running from
Tithonius Lacus to Margaritifer Sinus. The edge of the
chasm has a pronounced tributary valley system very similar
to water-eroded valleys on earth. However, the feature is
regarded as being geologically young and the eroding liquid
cannot have been water. The feature is twice as deep as
the Grand Canyon and six times as wide.
What kind of an event could have torn this great gash
a quarter of the way around Mars, melting the rock for a
width of 100 miles and causing it to flow into the rift?
Perhaps Mars once had a third satellite which came to a
grazing, catastrophic end.
Two other areas of Mars seen to be differentiated from
the generally cratered terrain. These are the polar regions
where circumferential ridges are the most typical feature,
somewhat akin to a series of terminal moraines pushed up
by the ice - or is it ’dry ice' of the polar caps.
Mars provides some comfort to those who persist in
ascribing to volcanic action the majority of the craters
on Mars or the moon, for there are on Mars some unmistakable
volcanic cones complete with calderas at the summit.
There are also areas on Mars of 'chaotic' terrain all
churned up into lumps and bumps with no identifiable pattern.
This might be evidence of earthquakes on the grand scale.
But most remarkable of all, to those who have looked at
Mars with a telescope, is the fact that the most obvious
visual features, like Syrtis Major, are absent in the
Mariner 9 pictures.OBSERVERS GROUPE MEETINGS - SEPT 8
Cathy Hall
Heare ye! Heare ye! Oure firste meetinge of the newe
season was heretofore heraldeth in by oure goode chairman,
Squire Tothill, at eighte houres and a quarter in the Geo-
physicalle Buildinge.
Kennethe of Hewitt-White, oure mete goode vice-chair­
man, did giveth a recourse with slides on the 1972 Generale
Assemblie in the porte of Vancouver, attendeth by the Stare
Trucke of Miller and faire. Squire Tothill dide maketh
mentionne that ideas for the 1973 Assemblie of Byetowne-on-
Ottawa would be mete rightly appreciatede.
A wanderer has been foundeth in the vaulte of the skie!
The comete, Giacobini-Zinner, is the causor of the specula­
tive aspectes that rightly surroundeth the meteore shower
of the place of Draco, thate ferocious beaste, in Oktober.
Thankes for its (re)diseoverie is dueth to Rolef of Meierie
and Jonathan of Shire Buchane, who dide showeth a slide of
ite for those personnes presente.
Youres trulie did showeth her slides of Stellafane and
the variouse sight-tubes for the skie at the A.T.M. conven-
tionne in the bige towns of Springfield, Vermonte.
Solare eclipse resultes wereth sparse, beinge sorelie
lacking, bute slides cameth through the darkenesse courtesie
of the greate Swami (Ricke of Laverie noe lesse) and Rolef
of Meierie. Et la piece de resistance - Sir Karle of Poiri­
ere and his fulle lengthe (welle, to be truthfulle, two
minutes of the glasse ande more) colourede filme strippe.
Mete goode luoke, or whateth?
Nexteth, Squire Kennethe did mentioneth the newe course
for the beginners in the skie-learninge, followeth by the
greate Sir Fredericke of Lossinge who did showeth to the
masses presents the wonders of the aurorae borealise of the
nite of summer June 17/18 of this yeare. Whate sighte to
eye of thinge most beautifule!
The maine talks was giveth by Misse Joaneth of Hoskin-
son, on the strange artificiale planetaria skie buildeth by
MacMillan of Vancouver Porte in the fairs lande to the weste
of the countrie. Ite was welle greeteth and enjoyemente was
excellente for the slides that dide presente themselves to
views. Thanks youwen!Fulle in mete of closings, Squire Tothill did announ-
eeth that the 29the orn 30the of Sept monthe would houseth
under the dometh of hopethfullie, er hopethfull, cleare
skie, a Stare Partie for to enjoyeth the multifolde wonders
opene to those of the nite ....
* * * * * * * * * * * * *
LIBRARY
Robert Dick
There are a few new additions to the Library, They
were picked up this summer during the voyage of the 'RASC
STAR TRUK'. They are booklets from Mount Palomar and Kitt
Peak Observatories containing pictures and text about each.
Those from Paloma
r have a history of the observatory,
from conception to completion. Accompanying the articles
are photographs of the construction and operation of the
giant reflector. One booklet contains drawings by Russell
Porter, one of the designers of the scope. These were made
before it was built. His skill in translating blueprints
to detailed sketches is unquestionable, as the drawings show.
Other literature obtained was a collection of descrip­
tions of some popular deep-sky objects, complemented by
photographs taken at the Wiison-Palomar observatories.
Only one is from Kitt Peak National Observatory. It
describes the history behind the selection of the site and
its construction. A number of the scopes are described in
detail along with the work that is carried out with them.
The booklet about Kitt Peak was bought by members of
the 'Star Truk' but those from Palomar were donated by Miss
Sherry Miller, a teacher, at a camp on Palomar Mountain.
I would like to thank her for her gift and for the hospi­
tality those of the camp bestowed upon us. They helped
make Mount Palomar the climax of our trip.
Read a good book lately? Talk about it in Astronotes.
* * * * * * * * * * * * *
DR. MORLEY'S TALK TO THE CENTRE
Dr. Lawrence Morley spoke on "Studying the Earth from
Space" on Sept 20, describing Canada's part in ERTS-1 and
showing some of the excellent pictures obtained.HOME-MADE EMULSIONS?
Rick Salmon
Having spent the last few days looking through the
literature in Tololo library, I've come up with something
interesting from a few Kodak pamphlets and other sources -
make your own photographic emulsions - sounds like fun!
If you used a pinhole camera - I've seen some fantastic
pinhole photos (or should I say "keyhole"?) it's possible to
MAKE everything from camera through to final print.
1. Camera. Using a 1/75" pinhole and hole-to-film distance
of 41⁄2 ", ASA 125 film takes 2 see exposure in bright sun.
Pinhole should be easy to make and are amply described
in ATM I, II, and III although they must be made large
enough to avoid serious diffraction problems over a 60 °
field or so.
2. Plates (emulsion). Requires the following to coat about
100 31⁄4 x
plates:
4
1⁄4
10 gm gelatin
32 gm potassium bromide
0.8 gm potassium iodide
40 gm silver nitrate
40 gm gelatin
Water (need not be distilled)
Clinical thermometer
Cheese cloth.
Sufficient clean glass
plates.
Stainless steel recep-
tacle 1-2 quarts.
Glass receptacle, open
and flat, one gallon.
The process itself consists of the following steps and
is rather more exacting and complicated than might first be
expected. Explanations will be given later.
The gelatin used can be either photographic quality
which comes in active and inactive forms, or ordinary 'house­
hold' clear gelatin. It would be well to remember that the
sensitivity of your final emulsion will depend in no small
way on the gelatin used.
The purpose of using a stainless steel container in much
of the procedure is to maintain rapid temperature equaliza­
tion between the emulsion and a water bath used to stabilize
temperatures.
Working in the light,
(a) Dissolve 10 gm gelatin in 12 oz of warm water.
(b) Add and dissolve 32 gm potassium bromide,
0.8 gm potassium iodide.(c) Raise the temperature to 130°F and hold (using a
water bath.)
Working in the darkroom in red light,
(d) Dissolve 40 gm silver nitrate in 400 cc water at
130°F and add to the emulsion at the rate of 20 cc
every 1⁄2 minute, for 10 minutes, stirring constantly,
(e) Hold the emulsion at 130°F for an additional 10
minutes, then let the temperature drop slowly,
(f) Soak the 40 gm gelatin in cold water until thorou-
ghly softened.
(g) Pour off excess water and add the gelatin to the
emulsion.
(h) Mix thoroughly, cool, and allow to set for 2-4 hrs.
(i) Scrape the set emulsion on to a square of cheese­
cloth and fold around it.
(j) Hold ’ball' (of emulsion) under cold water in a
pan and twist, forcing ’noodles' of emulsion
through the cloth. Pour off water.
(k) Onto the shreds or noodles (not your head, fool!)
pour 3 quarts of cold water. Leave 21⁄2 minutes.
Pour off 2 quarts and add 2 quarts more. Repeat
5 times.
(l) Heat the emulsion 15 min at 130 °F and slowly cool
to 104°F.
(m) Pour the emulsion on to a plate of glass and spread
uniformly. (4 cc for a 31⁄4 x 41⁄4 plate).
(n) Place plate on a level chilled metal plate until
set and dry.
Development is in any "high activity" developer such
as Dektol (dilute 1:1), or HC 110 (dilution A),
Plate is about ASA 8 (1/25 sec at f/8 in bright sun).
The procedure followed above, although obviously much
simplified, contains all the essential steps involved in
the making of a photographic emulsion, and together with a
little digging into the literature, helps illustrate the
problems and witchcraft involved in emulsion technology.
In choosing the gelatin, the highly diluted impurities
in the most "pure" gelatins have a decided effect on the
sensitivity of the emulsion. As Kenneth Mees pointed out,
when the quality of an extra-ordinarily sensitive emulsion
is found to result from the type of mustard the cows in a
particular pasture in Bavaria fed on, emulsion technologyseems more witchcraft than science!
The main reason for this 'hard to believe' dependence
is that minute traces of sulphur compounds in the gelatin
react with the silver halide during precipitation and the
latter re-crystallises to produce sensitivity centres on the
minute silver halide crystals. Chief among these "sensi­
tizers" is the thiosulphate ion (like in fixer). It was
Sheppard in 1925 who first pointed to the role of sulphur
in gelatin as a sensitizer, "Sensitization" here refers to
increased 'speed' of the emulsion, without materially affect­
ing its spectral response.
During the first step of making the emulsion it will be
noted that the silver halide is precipitated in the presence
of gelatin. This is essential since gelatin
acts not only
as a support, but as a peptizer
- preventing the coalescence
of the silver halide into large
clumps.
It will also be noted that
a combination of halides
(silver iodide and silver bromide) in solid solution is used
since this combination shows greater sensitivity and better
response characteristics than does either silver halide alone
In steps (d) and (e) the silver halide is formed at a
controlled rate, which in turn controls grain size and degree
of sensitization. This initial "ripening" stage, known as
physical ripening, can proceed in either of two directions:
Ostwald ripening (in which larger crystals grow at the expen­
se of smaller ones), or coalescence,
in which smaller crys­
tals merge to form larger crystals. Each 'physical ripening'
process has its separate effect on the "sensitization” of the
emulsion. The order in which halide and silver salts are
mixed also has dramatic effects on crystal sizes, and eventu­
ally on overall sensitivity characteristics.
The purpose of steps (l), ( j ) , and (k) is to wash the
emulsion of excess potassium bromide, potassium iodide, and
potassium nitrate, but it should be pointed out that complete
washing is neither necessary nor desirable since although
increased bromide ion concentration reduces sensitivity it
is also extremely important as an anti-foggant, leading to
a greatly increased shelf life.
Step (l) in the procedure is another ripening stage
known as chemical ripening, chemical sensitization, or diges-
tion, increasing sensitivity and contrast of the emulsion.It is here that the choice of gelatin is most critical.
Although somewhat unclear, it seems that a reaction with the
thiosulphate ions present in the gelatin produces silver
sulphide and it is the silver sulphide that is directly
responsible for the sensitization. Other methods of sensi­
tizing at this stage depend on the addition of gold salts or
a reducing agent.
* * * * * * * * * * * * *
THE XZ CYGNI PROJECT
Ken Hewitt-White
In the April issue of Astronotes, on page 4, I presen­
ted an article concerning the unusual qualities of an RR
Lyrae star in Cygnus. I have since run a brief set of ob­
servations on this star with the results printed here.
Little work was accomplished in April and Hay and none
at all in the early summer months due to Murphy's mystical
marvels. However in late August and early September, aided
by good skies, and with the help of Rolf Meier and Jon Bucha­
nan, I was able to round up some 112 observations of the var­
iable. The most successful nights' results are reproduced
on the opposite page in the form of light curves assembled
from our combined data. They show clearly the sudden rise
in magnitude that is characteristic of the RR Lyrae varia­
bles. After reaching maximum in this fashion, XZ Cygni
slowly fades to minimum beyond the right hand end of the
graph. One can easily see that most of the light curve is
visible in one night, another characteristic of these stars,
XZ Cygni will complete two periods in 111⁄2 hours so that
with each successive night the observer will see a peak or
some other point on the curve 11⁄2 hours earlier than the
same event the night before. This "phase shift" phenomenon
shows well on the graphs. If one places a ruler along the
slope of the rising magnitude it will be seen that all three
slopes line up perfectly with the ruler's edge. Thus, in
this short series, none of the O - C variations discussed
in the April Astronotes are apparent. Perhaps more obser­
vations over a longer time are needed.
I have sent off the observations we do have to Marvin
Baldwin of the AAVSO for appraisal. If the results are
acceptable then we may continue to work further and perhaps
reveal this unusual feature of XZ Cygni, namely that its
maximum peak is observed progressively earlier than the
predicted time.
It is an easy star, why not give it a go yourself?VARIABLES ( 2 )
Jon Buchanan
A red giant star, wisps of spicules dotting its sur­
face and several long tendrils thrust outwards, writhing
in dense magnetic fields, fighting the pull of gravity. A
faint cloud of condensed hydrogen atoms shrouds this red
giant in a thin cloud, absorbing part of the spectrum of
energy being released. A gasp! The surface slowly begins
to rise, fighting the pull of gravity as internal tempera­
tures and pressures, at a peak now, start to lessen as the
volume continues to swell, and swallows up the cloud of
hydrogen atoms.
Much later, the surface having risen noticeably, the
swelling slows, and hesitates. Matter still streams out­
ward from the star, fighting gravity, and some even starts
to condense and cool. A cooler surface now, internal
pressure relieved and having gone too far, gravity again
starts its pull and the surface starts to contract. Gravity
fighting n uclear reactions in a battle neither can totally
win. Each spicule now, as it breaks the surface, remains
longer above the receding surface, releasing more matter
that is condensing to
f
o
r
m another cloud of gas around the
star. As the volume decreases more, the temperature starts
to climb once more.
Eventually the shrin k in
g of this giant slows, coming
to an unstable position again as o nce more gravity has
pulled in too far and now internal nuclear pressures p ush
outward. One ’heartbeat' of a star!
This, of course, is a variable star. It is a long-
period red variable, or Mira type. This category of stars
is typified by red stars of spectral classes M, R, M, and
S, giants in size and luminosity. With periods from roughly
100 to 1000 days and a range in magnitude of 3, on the
average, they can be observed by even the most casual ob­
server. In fact almost all the variables in the variable
star program for this year are Mira type variables: G Herc,
X Her, W Ori, RX Lep, and I think TX Pisc and RR CrB also
are in this category. Periods for these variables range
from 60 to 200 days, and some have complex variations so
that no period has been determined by the professionals,
who call them Irregular.
The reason for the changes in magnitude of these vari-
ables has to do with the fact that they are, in essence,rather cool stars. The wavelengths of emitted radiation
are dependent on temperature, just as temperature determines
whether a hot metal glows 'red' or 'white'. At maximum
temperature the star emits radiation, some falling in the
visible range, notably the red end of the spectrum. At its
coolest, though the amount of radiation being emitted m y
not have changed noticeably, the wavelengths of the emitted
radiation have been shifted towards the red end of the
spectrum, and as such some of the light falling into the
visible range has been shifted to the infrared region, and
is therefore invisible to the naked eye. This, of course,
results in a more pronounced drop in the visible magnitude
range.
Though the total output of energy of a star may not
change, its temperature, and thus luminosity and wavelength
emission peak, are affected by its size. A small volume
will be hotter due to more energy per unit volume, and thus
will emit more energy at shorter wavelengths (towards the
ultraviolet) while a large volume will be cooler, and emit
more towards the infrared end of the spectrum.
Around some of these stars, from observations of
absorption bands only visible near minimum light, a cooler
cloud envelope must exist. The surface expands faster than
the envelope, indicating, perhaps, hot shells of gas moving
outward.
These variables are found in both populations of the
Galaxy. In Population I, being the galactic disk of the
Milky May, the 12-month or so variables are most commonly
found, while in Population II, the galactic halo, roughly a
sphere surrounding the Milky Way galaxy, the shorter, 6-month
variables are scattered.
Usually the longer the period, the greater the visual
range, the lower the visual luminosity and the later the
spectral type.
Examples of two of these stars are given below. Due to
the nature of these stars being red, the human eye has diffi­
culty in making accurate estimates. This is most obvious
with G Hercules, an M6 star, of period 80 days and a range
of 4 .4 to 6.0. A light curve of this variable from obser­
vations of Ken Hewitt-White appears overleaf. Hobbles of
0.2 to 0.3 magnitude can be expected with such a red star,
and no definite period can be seen, again pointing to thefact that many years of observations are needed to find
such a period as 80 days.
The second graph has been taken from Sky & Telescope
because I have not found a good graph that clearly shows a
period. This is T Hercules, a Mira type variable with a
period of 165 days and a vast range from 14.0 to 8.5. This
was from the July 1971 issue, on page 55, where a finder
chart for this variable may be found for those interested
in trying it, E.H. Mayer observed this with a 6-inch
reflector.
Ernst M . Mayer, Sky & Telescope July 19 72
V o l . 4 2 , N o . 1 , Pg. 5 5PERSEID OBSERVATIONS FROM KINGSTON, ONT.
Peter Ryback
At Kingston, the night of the maximum of the Perseid
meteor shower, Aug 11/12, was cloudy. Nevertheless, both
photographic and visual observations were made on the nights
either side of the maxima. While Bob Baran operated up to
4 cameras, Don Retellack, Paul Brown, Ralph Peter and I made
the visual observations some 15 miles west of Kingston.
Since only two observers, at most, observed visually at one
time, the total count of meteors was not very high. However,
the mean rate of meteors seen was 20 per hour for the two
nights observed.
A total of four meteors were photographed, all on the
first night. Two of these were observed visually. Weak
aurorae, in the fora of small pulsating spots, appeared for
some period during both nights, but were never bright enough
to interfere with meteor observations.
Night 10 -min periods Aug 10/11 30 112 Perseids
51 nons
163 total 2
Aug 12/13 34 98 Perseids
27 nons
125 total 1
Totals
M
eteors
210 Perseids
78 nons
288 total
* * * * * * * * * * * * *
64
VISIT PLANNED TO SOLAR OBSERVATORY
Observers
1.5
Barry Matthews
On Saturday October 14, members and friends will have
the opportunity to see a professional solar telescope. The
scope in question is the new solar observatory at Shirley's
Bay (remember the Quiet Site?), Dr. Vic Gaizauskas will be
on hand from 2 to 5 pm to explain the intricacies of solar
research. Members with oars should meet at the Dominion
Observatory at 1:15 to proceed to the Q.S.
Any further information may be obtained from me by
calling 829-7237.WORK FOR SOLAR OBSERVERS!
Barry Matthews
Robert Pike of the Toronto Centre has requested that
our solar observers aid his in his studies of the Wilson
effect and sunspot motions. To meet this request the foll­
owing information will be required:
(A) Drawings/photos on a daily basis of spots near the
solar limb.
( b ) Full-disk drawings or photos to show spot motion
and activity centres.
I will be in touch with Mr. Pike and will act as collec­
tion agent for the Ottawa area. Some of the older members
will recall the solar patrol and solar dark room that forced
the Centre into a leading solar group. Report forms will be
available for distribution in the near future. Call me if
you are interested.
As sons of you are aware I have been playing around
with solar spectrography, primarily H-Alpha prominences and
will be commencing a series of articles on making and using
spectroscopes. If you have any information on this subject
I would like to see it.
* * * * * * * * * * * * *
ATTENTION BEGINNERS AND NEW MEMBERS!!
Ken Hewitt-White
By popular demand a series of beginning astronomy
courses will begin again this fall. Unlike the spring, this
series, still sponsored by the Observers Group, will run
all winter. The first session will begin at 8:00 pm, Friday
October 20. There will be a meeting on the third Friday of
every month thereafter.
At these meetings we hope to review the fundamentals
of astronomy and telescopy at a level understandable to all.
With more time available at the 7 or 8 meetings we will be
able to cover less at each meeting but be more intensive
and methodical about what we do cover.
Much of what will be taught is covered very nicely in
Sam Brown's "All About Telescopes" and this book will serve
as a basis for our course outline. If you want to follow
along with this book we encourage you to do so but having
a copy is by no means obligatory. Perhaps if there is-14-
sufficient interest we can order copies of the book in bulk
for our 'students'. More likely we will just xerox off any
really important facts or tables that you might need.
These meetings promise to be informal. Bring your
problems and questions. If attendance holds up well,
all the meetings will be in the usual geophysical library,
familiar to us all. See you there!
* * * * * * * * * * * **
THE SCHLOSSING SAGA (15)
Tom Tothill
"How's your fuel now, Red?" said Bedlington Tean.
"Bopping the F."
"You're Go for Synch."
"Sink?
Sink who?"
"Just press the SYNCH button and LONG 90.
will do the rest. It's a cinch."
The System
"Worst punster I know", thought Schlossing and Tean
simultaneously.
"O.K.
Done." said Sehlossing.
"The System will fire on the back side at 4 g's.
your back can stand it?" said Tean.
Think
"It will this time." said Schlossing, leaving Tean with
a puzzled expression. Could weightlessness have had a
therapeutic effect on Schlossing's back? And if so, how did
he know before trying it? But Schlossing would soon be
setting and he didn't take the time to enquire further.
"Next time we talk, you'll be in synchronous orbit,"
he said, "And ready for the payoff."
It was Schlossing's turn for the puzzled expression.
What did Tean mean by the payoff?
Who was getting paid
off? And for what? One thing he was pretty sure of - he
himself wouldn't make a dime out of the whole darn trip.
Could the whole dratted Ground Organization be playing him
for profit?AST RO NOTES
TO
Ms. Rosemary Freeman
National Secretary
The Royal Astronomical
Society of Canada
2S2 College St.,
Toronto 130, Ontario.