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Vol. 12, No. 6 $2.00 a year October, 1973
Editor: Rolf Meier 77 Meadowlands Dr. W., K2G 2R9
Addresses: Mary Grey Dominion Observatory, 994-5474
Circulation: Ted Bean 399 McLeod Street, K2P 1A5
DEEP SKY WEEKEND AT NORTH MOUNTAIN OBSERVATORY
The weekend of October 20 will provide an opportunity for everyone to become familiar with North Mountain Observatory. Here we have our 16-inch telescope. Many members may not be aware of it, but they are welcome to use the 16-inch and bring out their own telescopes almost anytime. There is also space available for overnight camping. This particular weekend will be used to introduce our new members to this fine observing site. All members are encouraged to come, so that astronomical experience can be shared in an informal session at the telescopes. It is expected that most people will come out late afternoon of Friday, October
19. There should be time allowed to set up tents and telescopes in daylight. The Friday night will be an observing session, and it is expected that there will be plenty of telescopes to look through. Among the objects sure to be scrutinized are Mars, near opposition, and Comet Kohoutek, by then visible in binoculars. Saturday can be spent talking to other members about their telescopes. It will be shown how the 15-inch works, and how it is used for photography. Saturday night again will be an observational session. It is hoped that many people will take advantage of this dual star night. Of course, we cannot guarantee clear weather, but in case of cloud, the event will be put off to the next weekend. It will be cold camping at this time of year, but warm blankets will solve that problem. Among the advantages
of overnight camping are that it avoids driving home late at
night, tired, and leaving the observatory with headlights disturbing everyone still there. The younger members may have problems in getting transportation or tenting accomodation for the weekend. Please call Barry Matthews (829-7237) or Rolf Meier (224-1200) and tell us your needs or how you can help in any way. We would ask, however, that you supply your own food and water. Maps on how to find the observatory will be available at the Observers Group meeting on October 5 and at the Center meeting on October 17. A complete announcement will take place at the observers Group meeting and details will be discussed. We hope to make this an annual event, to coincide with the date of the official opening of the observatory, October 22, 1971.
OBSERVERS GROUP MEETING- SEPT. 7 Cathy Hall
Did you know that there were 64 people at this meeting, with 66% members? Compare this to last year at this time when there were 47 people, 70% members. We've grown, and were attracting more new people too!
Ted Bean opened the meeting, followed by Karl Poirier with suggestions for a trend towards more active beginner participation, more informative talks, and elimination of inactive coordinators.
By the way, our meteor coordinator, for the present at least, will be Les MacDonald, one of the original members of the meteor team of 1961. Phone 225-1140 if you'd like to really get some observing in. Transportation can be provided.
Photographic results of the total solar eclipse of June 30 were shown by Allen Miller, Rob Dick, and yours truly. Each of us took different ships to Africa to view this specatcle. Allen aimed for prominence shots, while Rob and I were after the whole thing. They all turned out very well indeed.
Following this, progress on the radio telescope at Quiet Site was described by Karl, with slides taken there recently. Rolf Meier showed several deep sky shots taken at North Mountain Observatory of the Andromeda Galaxy, the Dumbell Nebula, and the Omega Nebula. They were absolutely beautiful.
The team of Welch and Somers, (Doug and Doug) talked briefly on asteroid searching and offered position coordinates to all interested. Phone 829-2547.
Lastly, a library notice by Barry Matthews: books may be borrowed from the main RASC library in Toronto by mail. Talk to Barry for information on this service, free to all paid-up members.
All those who wish to give a presentation at the next Observers Group meetingshould contact the Vice Chairman, Karl Poirier (835-2848), two weeks before the meeting. He will call you 5 days before to tell you how you fit in.
PHOTOGRAPHIC PAPERS FOR ASTRONOMY Doug Beaton
It is impossible to determine the perfect paper for each type of astronomical photograph, but I would like to mention a few I have tried with good results.
Auroras rquire high contrast and I have found that Agfa BH1-5, in addition to providing high contrast, gives the sky background a richly toned black that cannot be found on other papers.
Mars prints well on Agfa BN or BW112 papers. These papers seem to give a tone somewhat similar to the appearance of the planet through the telescope. Jupiter and Saturn usually require high contrast to preserve their surface detail and since grain is a problem I usually stick to Kodabromide E-4. If you prefer a glossy print then F-4 or Ilford IB4.1P work well.
Lunar shots should always be on glossy papers of medium contrast like F-3 or IB3.1P.
By far the best paper for extended nebulae is Ilfords IB4.24K. The contrast is there if you need it and the semimatte surface is very pleasing to look at.
Stellar or asteroid photographs work best on Agfa BEH1-6. Its extreme contrast helps to preserve those fainter magnitudes while giving the background a very black
The most frequent mistake made on astronomical prints is that of overexposure. An extreme overexposure will give the print an overall greyish tone and sometimes a grey mottled pattern in it. If this happens to you then reduce your exposure by a third or a half. Let the print stay in the developer 2 minutes or a bit longer if you have to. Always make sure that the developer isn't exhausted and remember that proper tray agitation is very important to ensure consistent results.
I think that people enjoy the picture more if it is either printed on double weight paper or else mounted on cardboard. If you do not prefer this added cost then at least use print flattener. About $1.80 will give you a two year supply.
I have always used Kodak D-11 for my prints but D-8 and D-19 work equally well.
THE COLORS OF MARS Rolf Meier
Most of the planets are constantly covered with clouds. We have never seen the surface of Venus, Jupiter, Saturn, Uranus, or Neptune. Mercury and Mars are the only planets we have ever seen surface features on. Mercury is rarely, and then only briefly and poorly observable. Mars is the only planet whose surface has been consistently observed from Earth, and in some detail.
Earth-based mapping has been replaced by detailed Mariner mapping. Even so, Mariner close-ups do not reveal the different colored areas which are so clearly visible from Earth.
There are 3 basic color areas on Mars. The most dominant is the salmon-colored "background" which gives Mars the hue which is visible to the unaided eye. The polar caps are visible in any small telescope. They are brilliant white. The dark areas on Mars need a good telescope to be seen in detail. The color of these areas is questionable. I have always maintained that they are grey, with a shade of dark brown. At no time have I seen green, although this is what many observers report. I believe this is just an optical illusion, caused by seeing a neutral color (grey)
next to a brilliant color. The reddish background would cause the complimentary color, green, to be seen on the grey surface. Thus the effect would even be seen looking at a photograph.
There is a large depressed area on Mars, the Hellas region. In a telescope it appears as a light color, somewhat the same shade as the background. It looks like a featureless desert, both in Earth telescopes and in Mariner shots.
Occassionaly there are dust storms and clouds of some kind on Mars. They are sometimes yellowish, but during the widespread dust storms of 1971, the color of Mars was a uniform salmon color.
The colors of Martian features are our only clue as to the materials of the surface. The background looks like it may be some kind of oxide. For those of you who have polished telescope mirrors, try to remeber how close the color or Barnesite or Cerium Oxide matched the color of the Martian background.
The darker areas may be terrain stripped of dust, so that the baren rock surface show through. I think it resembles iron ore, or just plain rust.
It is hard to reproduce on paper exactly the colors one sees through a telescope. It is somewhat like adjusting a color television for flesh tones by holding your hand next to the screen. An exact match is difficult because your hand is reflecting incident light while the television set is producing light of its own.
A good start is to study the apparent color very carefully. Then, with oil paint, or water color, or colored pencil, recreate the color on a small disc. Place this on a dark background. Make several with various shades so you can pick the best one.
The comparison test at the telescope is difficult. Mars is being lit by sunlight, while the colors you have on your piece of paper are being lit by a flashlight. The flashlight looks white at night, but in the daytime it is yellowish. The problem is in getting a natural source of light, most like sunlight, or the color you pick as a match will appear different under natural lighting.
The best source of light may be a small fluorescent tube, with a small opening to let out a little light. Dark adaptation is not essential because Mars is quite bright. Compare the color you pick with that kind of light, and a choice made by tungsten lamp, or flashlight.
One idea worth trying is to use moonlight, which closely resembles sunlight in color. Even a full Moon is not brilliant enough to show colors clearly, but some brilliant amateur may think of a way to use mirrors and lenses to concentrate moonlight enough to be useful.
Once you put down on paper what the true colors of Mars are, you can investigate what earthly substances are similar. Go around your neighbourhood, comparing the colors on your little discs to all the rocks you can find. Try to discover the actual surface materials of Kars before they send a rocket to the surface.
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A CONSTELLATION REVIEW (3 ) Doug Welch and Doug Somers
This month we are offering you the constellation of Aquarius. Up to the 21 hour line, all the objects have been described very well by Ken Hewitt-White and Allen Miller in their excellent book, "A Midsummer-Night's Dream" so we will not bother with them here. Fortunately, only 2 objects are missing because of that.
Moving eastward, we immediately come to NGC 7009, alias the Saturn Nebula. In an 8-inch telescope this planetary shows no Saturn effect. In the 16-inch spikes can be seen on a good night. At visual magnitude 8.4, it can be seen in binoculars, though a higher powered scope is needed to show a disc. It is about 30" in diameter so look closely and you can't miss it. The coordinates for it are, RA 21h 01.5m, Dec 11° 34 S.
NGC 7171 is located at RA 21h 58.3m, Dec 13° 31 S. This is a very faint galaxy that should be within range of an 8-inch, from my experiences with this type of faint galaxy. I have not been able to observe it but I hope to have a result for November. Its magnitude is 13.1 and its size is 2.1' by 0.9'.
NGC 7184, at RA 21h 59.9m, Dec 21° 04 S, is much the same case as 7171 in that it has not been observed yet. Its surface brightness is about the same. It is 12.0 mag. but elongated, its size being 5.1' by 0.9'.
NGC 7218, 7252, and 7377 are all due for next month.
NGC 7293, the Helix Nebula is next. This planetary, the largest in the sky, spans Œ degree. Its integrated mag. is 6.5, but this is deceiving. It is possible to see it with 50 mm binoculars under country skies. My 8-inch shows the hole in it at low power but with high power it vanishes. The position is RA 22h 27.0m, Dec 21° 06' S. Look for something fuzzy.
NGG 7309 is a galaxy located at RA 22h 31.6m, Dec 10° 3 7 ' S. With an 8-inch 'scope it is visible at high power. It is fairly round, being 1.4 by 1.1'.
NGC 7371 is nearby at 22h 43.4m, Dec 11° 16 S. This is much more easily seen than 7309. High power should be used although it was seen dimly at low. Averted vision helps. It is round, 1 in diameter.
NGC 7377 couldnt be found. NGC 7392 was seen faintly at RA 22h 45.1m, Dec 22° 35 S.
NGC 7492 is an impossible globular, and anybody I know that has tried to find it has failed. Forget about it and you will save your sanity. I have tried repeatedly and to no avail.
NGC 7585 is at RA 23h 15.4m, Dec 4° 56 S. This galaxy was fairly dim. My notes show that high power was best. It was also round.
NGC 7600 is located at RA 23h 16.3m, Dec 7° 52' S and was easier than 7585. Notes show that high power and averted vision show it much more clearly. It seemed ever so slightly elongated.
NGC 7606 is probably the best galaxy in Aquarius. Notes show it to be "fairly bright, extended, easy at low power, starish core, no detail". In fact, this galaxy is 11.5 mag. and 4.4 by 1.5. City viewers may not get a glimpse of it though it is not impossible. Find this sight at RA 23h 16.5m, Dec 8° 46. NGC 7721 will be in next month.
NGC 7727 and 7723 were both quite easily seen. A finder chart from Webb's for all objects would be much more help than Dougs chart which just gives their rough locations.
On the night of Sept. 21, the author of this article and myself looked for this object with the 16-inch. The transparency was good, but we looked a long time for this object. Finally, I examined the charts very carefully and pinpointed the exact spot in the star field where this globular ought to be. At 125-power, it was indeed there, possibly at the limit of detectability. It is extremely faint for its size. There is no indication of a starry
core, just a faint, round smudge of light about 3 ' in diameter. -Ed.
COMET KOHOUTEK 1973 f Jon Buchanan
The following information is for your help in finding the comet. Table headings are: DATE (this one is obvious); RA - right ascention in hours h and minutes m; DEC - declination of the comet in degrees and minutes; Ml is one estimate of the comet's brightness and MS is a different one (one or the other may be correct, depending on how the comet behaves); NUC - the magnitude of the nucleus; ALT - the approximate height of the comet above the horizon in degrees at the start of twilight at the time shown. MT and ET refer to morning and evening twilight, when the comet will not be visible in a dark sky. Figures are from the ALPO
Ephemeris for Comet Kohoutek, Comets Section, July 19, 1973.
X-RAYS IN THE SKY Mark Mongeau
Ten years have passed since the discovery of the first
celestial object, other than the sun, known to emit
x-rays, A total of 120 objects have been discovered which
give out x-rays. These have been studied in great detail.
The nature of the experimental results has startled many
x-ray astronomers. Some of these objects are compact while
others involve galaxies. The large and small clouds of
Magellan are included. Unfortunately most of these x-ray
objects are not or have not been related with any light or
radio emitting objects.
A group of astronomers at the Naval Research Lab in
West Virginia observed the Crab Nebula as the moon eclipsed
it and found the x-ray emitting area was 1 min. of arc
across. This year an orbital space station was sent up,
to join others of its kind, in observing x-ray regions.
From these experiments will come answers to questions and
more questions for future generations to answer.
The 39th Stellafane Convention was held on Saturday, August 4, 1973, near Springfield, Vermont. About 20 people from Ottawa attended this year's event. The Friday evening program consisted of a monitored slide session under the tent to "provide an opportunity for you to share your astronomical experiences and slide pictures with those present". Unfortunately, too many of the showings were repetetive desert shots and boat shots and poor eclipse photos, between long periods of disorganization. However, the talk given by Fred Lossing on behalf of the work done at North
Mountain Observatory was very well received.
On Saturday the judging of the telescopes took place. Among the Canadian winners was a compound telescope built by a Montreal member of the RASC. His telescope was also on display at our General Assembly. Saturday night was an observational night, and many fine objects were viewed under clear Vermont skies.
Next year Ottawa is again expected to produce several unique telescope entries.
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DEEP SKY Rubber Duck
During my trip to see the solar eclipse off Africa I tried to take advantage of those southern latitudes (about 20° north) to photograph and draw some of the star fields and objects. For this reason I took along my 8-inch f/5 reflector. But as luck would have it, the further south we steamed the higher the haze on the horizon rose.
When we were about 30° north, I scanned the southern horizon with a pair of borrowed binoculars, hoping to see constellations such as Ara and Norma.(seen from Kitt Peak last summer) Haze blackened up to 25° above the horizon. The only really noticible object there was my old. friend M-7 (NGC 6475), at RA 17h 50.7m, Dec 34° 48 S.
It consists of about 100 stars as seen in binos, 50' in diameter and shining at magnitude 5. M-7 is the acclaimed cluster on the eastern border of Scorpio just north-east of the Scorpions tail. Its distance is 800 l.y., or twice as far as the Pleiades.
Two "smaller" objects on the edge of the cluster are NGC 6453 and H-18. 6453 is a globular cluster on the northwest edge. (it was not resolved in an 8-inch f/8 , KHW & Miller) H-18 is a sparse cluster on the south-east edge. Just 3 degrees south at 37° S is an object that wasnt seen at all, NGC 6400. It is a 6 diameter open cluster, magnitude 9.
FOR SALE: 6-inch Criterion "Dynascope", original cost $300,
asking $210, call Barry Matthews at 829-7237.
SOME LATE NEWS: The 1973 General Assembly of the Royal
Astronomical Society of Canada was held in Ottawa on the campus of Carleton University on the weekend of May 26-27 of this year. Among memorable events are the showing of the Apollo 17 movie, an increase in RASC membership fees, tours of North Mountain Observatory, an excellent dinner speech at the annual banquet, and the activities in room 901. There were also many unique displays set up in the Tory Building. Next years GA will be held in Winnipeg.
DICHROIC FOG Doug Beaton
If you notice that your negatives have a purplish color to them, then they suffer from a condition called dichroic fog.
When the negative is placed in the sodium thiosulphate solution (fixer) during development procedures, the undeveloped silver halide used in the emulsion is converted into colorless salts called argentothiosulphates. If any active developer is present, either in the film or in the fixer solution, then this developer converts these salts into silver.
The grains of the excess collodial silver are about the size of the wavelengths of visible light. They form a uniform deposit over the negative and hence give it that purplish color. This silver deposit may be wiped off to some extent from the wet negative but once allowed to dry it may be fairly permanent and it will degrade the final print somewhat.
The answer to the fogging is to make sure that the fixer is not contaminated. Use a stop bath, always making sure it is of the proper concentration. Give this solution time to work but do not use toexcess. Also, be sure that the fixer is not past its recommended capacity.
To test for excess silver, take 25 cc of your fixer and add 1 cc of a 5% potassium iodide solution. If the mixture turns milky and remains so upon shaking then it is time to discard that fixer.
The new yearly fee structure as determined at the
General Assembly's business meeting is as follows:
18 and under as of Oct. 1,1973....$7.50
And now, back by popular demand
THE SCHLOSSING SAGA (23) Tom Tothill
Red Schlossing did not perform the One-Eighty as instructed, but only a Ninety, for his eagle eye had caught a glimpse of something in the direction of the vanished Planet X that he wanted to get a better view of, broadside on.
At first he thought he had been mistaken, for there was nothing there - just a pattern of stars. Then one of them winked out, and another. Then some more winked on away over to his left. Then he realized, incredulously, that a whole great field of stars was moving slowly, left to right, against the surrounding stellar background. Moreover, the constellations in the moving field were unrecognizable until Sagittarius sailed in with the handle
of the teapot on the right!
"But Sagittarius ought to be behind me, not in front", he mused, "And anyway, its hidden in the black hole." But he couldn't deny that there it was ahead, seemingly larger than life-size though not too sharp, and most definitely backwards "As if I was seeing it in a mirror."
"Holy Shenanigans!" he exclaimed,"It is a mirror!", for now he could make out the outline of a huge ellipse in the sky. The moving stars were all within the ellipse, and the familiar, proper stars were all outside it. The ellipse was rapidly elongating in the vertical direction and closing up cross-wise. Schlossing hastily completed his One-Eighty for fear of hitting it, and watched dumbfounded as it came edge-on, the last stars racing across the narrowing slit as he passed by. On the back were
mechanisms, clusters of thrusters maybe, and frameworks, and levers, and cables. The whole thing was gigantic - thousands of miles of aperture, he guessed. Wow! How would that rate at Stellafane, he wondered.
Now if that were an ellipsoidal mirror, with means of adjusting its curvature a trifle, one could take an image of a planet like the Earth and throw it to a focus somewhere else.
"But Who", mused Schlossing, Would need to keep an eye on the back side of the earth as well?"
* A r t i c l e s d u e O c t . 1 9 - E d . *
Ms . Rosemary Freeman
The Royal Astronomical
Society of Canada
252 Colege St.,
Toronto 130, Ontario .