AstroNotes 1973 May Vol: 12 issue 05



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Vol. 12, No. 5  A S T R O N O T E S $2.00 a year
May, 1973
Editor: Rolf Meier 77 Meadowlaads Dr.W., K2G 2R9
Addresses: Mary Grey Dom. Observatory, 994-5474
Circulation: Ted Bean 399 McLeod Street, K2P 1A5
If memory serves, I first met Too Tothill on the late afternoon of August 12, 1967. He was a bit depressed on that occassion because he had spent considerable time and effort organizing the Observers Group’s Centenial project a week's camping trip to Point Petrie on Lake Ontario- but no one seemed intent on going. Tom had come out to the Quiet Site to see the meteor bunch and find out if they were coming or not. Just a wide-eyed newcomer at the time, I was interested in anything that was going on. Dave Paterson and I, buddies always, decided we would go even if the others didn't, and if Tom thought it would be worth it. He did. Just the three of us went for the week. Tom had his almost-finished eight-inch with him and with that we toured the sky with fashionable ease. I guess Dave and I spent more time with the sky in that one week than ever before. And we loved it. We found out that the Observers Group of Ottawa was made of admirable stuff- not just of eager young people but of sincere, hard-working adults tooone in particular: Tom Tothill.
Tom has given a kind of effort and polish to his work
that is noticeable in only a few of the best amateurs. His contributions to the Observers Group have been far too many to mention here. His efforts have gone much beyond the many duties he has performed as a Chairman, Vice-Chairman, Editor, and a Co-ordinator. Suffice to say that he has been the kind of avid observer and supporter that our group has often been privileged to enjoy but been rarely worthy of having.
What has Tom taught us, then? He has taught us that you only get back what you put into something. If you love this group, you put a lot into it, and then you make it a success, and then you get the gratifying kickback of more activity and greater fun.
If we want to thank Tom for what he has put into this astronomy group, we might just try by continuing on with the kind of effort he himself has shown since 1965. There are a number of old hands leaving the scene now and we need new effort from both young and old, newcomer and veteran, to keep the group on its feet.
This astronomy group has been pushing forth with staggering success since that August in 1967. Tom Tothill has figured a good deal in that success. Let us wish him all the very best with his new home in Vancouver and show our appreciation to him by keeping this Observers Group great.
Good luck, Tom! # # # # # # # # #
Last month the Observers Group presented a special meeting for the Ottawa Center. There were approximately 95 persons present, including several RASC members in from Montreal.
Mrs. Henderson opened the meeting with announcements concerning a film on the Crab Nebula on the 10th of May, the General Assembly, and the departure of one of our long-time active members, Tom Tothill, for Vancouver. Good luck, Tom, with your Ocean Engineering Center!
The meeting was then turned over to Ken Hewitt-White, the chairman of our Observers Group, who introduced our program. Barry Matthews gave a brief rundown on several projects designed to get members out observing: the keeping of a logbook and a search for Messier objects. He also had copies of the "beginners' package" on sale for those with lots of ambition, but lack of know-how as to how to get into the observing game.
Two of our newer and younger members, Doug Welch and Doug Somers, presented a well-documented slide talk on deep sky objects, as well as samples of their results of asteroid, lunar, and solar observations. Their enthusiasm and resoucefulness were evident from results obtained with hand-guiding.
Next, "Einstein should have been a Greek" or "An epicyclebuilt for two" was the title of a talk given by Karl Poirier. He covered the main astronomical discoveries up to the time of the Greeks Romans, complete with witticisms. (... e.g., Aristothill the Greek)
Finally, a film made by Allen Tiller and crew of the launching of Apollo 17 was shown. The photography was excellent and the soundtrack was put together with a great deal of ingenuity.(an understatement -Ed.) Thanks for a very enjoyable piece of work*.
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M 3, M 53 Rob Dick
These two globular clusters are to be found close to the meridian around mid-May at about 22:00 hours. M 3 is located at...
RA 13h 40m Dec 28° 38'
Also known (by a few) as NGC 5272, it is just inside the constellation of Canes Venatici, (The Hunting Dogs) by the north-west corner of Bootes (The Herdsman), and the northeast corner of the constellation Coma Berenices (Berenices’ Hair). It is about 9' in diameter and shines at about magnitude 6.3. (i.e. fairly bright)
The cluster is 110 light-years in diameter at a distance of almost 40,000 light-years. It appears to be approaching us at 150 km/sec. Of its many stars, 170 are RR Lyra type variables. (see J. Buchanan’s series)
M 53 (NGC 5024) is about 1œ magnitudes dimmer than M 3, at 7.7 with an angular diameter of 3.3’ of arc. It is in Coma Berenices at...
RA 13h 10.5m Dec 18° 26’
and 60,000 light-years away. It is approaching at a speed of 122 km/sec.
It is found just north-east of Alpha Coma Berineces,which is about 1° south and 15° west of Alpha Bootes. (Arcturus) It is slightly oval in shape and, as with many globulars in smaller scopes, has a bright nucleus and nebulous outer region. (unresolved stars)
Since globulars are in the "halo" of the galaxy, theyare usually seen in the higher latitudes of the galactic plane and away from the milky way.
At first glance, there is little to see in a globular but under long, careful scrutiny, the cluster grows as the out-lying stars are glimpsed. Take your time! You'll see it!
With summer presumably coming soon, one would expect to find more observers at North Mountain, probably many new ones who have found the winter too uncomfortable to leave town. To these people then, a note: bring your equipment, no matter how modest! Besides relieving the great pressure otherwise put on the 16", you may discover the potential of say, your 4Œ", under a dark sky.
Also, bring your camera. Any one of the experts who are bound to be there can show you what can be done. They will be only too glad to help you. (remember, all you have to do is ask.)
I never dared to tell this story at the time, but... In the back garden there stands a ring of concrete, circular and level within an eighth of an inch, reinforced one continuous monolithic structure, beautiful to behold.
It carries the floor of the observatory and the rotating building, but not the telescope; that is on a separate pylon.
I measured the hole in the ground and the space between the forms, and worked out the volume by slide rule. It came to 4.8 cubic yards - far too much to mix by hand, so I ordered 5 yards of ready-mix.
The giant truck arrived at 17:30. (we finished levelling the forms at 17:29 and had hoped for a well-earned beer) The driver didn’t mind backing across my lawn provided I took responsibility for the damage.
He backed into the ditch, stuck, tried again, stuck again, and finally made it with a run. On arrival at the hole, he took one look at it and said a yard and a half ought to do it - what did I need 5 for?
I explained that the hole would take 4.8 and I had a step to pour around the front. He looked at me a little quizzically, and promptly offered $100 if we failed to fill the hole.
It took about 20 minutes to fill the lower hole and trowel the top smooth. Then we put on the coping forms and filled that up.
There still seemed to be a little concrete left in the truck, so the driver took the lawn and the ditch with a run (deepening the ruts another 6 inches) and backed into the driveway. We poured the step, and took a barrow load to touch up another step. The driver then asked if I'd like to pour a new floor on the garage.
Visualising a small untidy puddle on the lowest part, I said no, paid him the $80, and he drove off to dump what was left before it set in the barrel of the truck.
I spent half the night smoothing up the concrete as it hardened, and the next day checked my figures very carefully. It came to 4.78 yards.
It finally hit me on the third day. There are twenty-seven cubic feet in a yard - not nine. Somewhere in the concrete plant there is a hole filled with $50.40 worth of my concrete.
And that's serious. # # # # # # # # #
Mr. Houston has written to Tom Tothill as follows:
"Pass on my admiration for your Ottawa bulletin — a very fine publication. Rolf Meier has a neat idea. Heating is the only answer to dew. Hie idea is most original, but I think too complicated. For example, I put a heating coil of flat nichrome wire around the spare socket on my turret eyepiece. After five minutes both the eyepieces in the other sockets are protected. Also I can change occulars easily without changing connections. I use 4 volts AC from a toy transformer.
My finder 2"x8" aluminum tube merely has a heating coil around its middle, but the heat travels to both ends and holds off the dew nicely. The 4" Alvin Clarke has the heater wrapped around a stainless steel dew-cap. The heaters are wired to the main power switch. When I enter the observatory and turn the power on the optical elements are all at thermal equilibrium by the time I have my charts selected and am ready to observe.— -Course at the start, when the heat first goes on, the images do a Richter 9 gyration, but in 4-5 minutes they settle down for the night.
Curiously, the use of heaters sharply improves the images even when there is no dew forming. Get your bright boys to figure that one out."
(— bright boys please step forward— was Tom’s remark)
A CONSTELLATION REVIEW (1) Douglas Somers, Douglas Welch
Cancer is an elusive configuration preceding Leo and trailing Gemini in the spring skies. Although it is not near the Milk Way it has two clusters to its fame. From the city this constellation is dim and we usually forget it is there. We are sure that those who migrate to North Mountain will be able to find it easily. The objects are listed in order of difficulty.
At 8h 37.5m and 19° 52' you will find the open cluster M 44. Otherwise known as the Beehive or sometimes Prae sepe, this cluster is 3.7 mag. Its diameter is 95', making it 1œ times the diameter of the full moon. This cluster, although containing 75 stars, is a better rich field or binocular object since the stars are so widely spread. To locate it, look between Gamma and Delta Cancri and a little to the west. This sparkling group will immediately be seen. The Beehive should be easily seen with the naked eye with fair sky conditions. It will appear as a soft glow. Sky and Tel. says that if it can't be seen with your eyes then rain is on the way. See if this works for you.
Asteroid Euterpe (27) passed through here between the 10th and 17th of April at 12th mag. Did someone secure a photo?
M 67 is the other open cluster in Cancer, due west from Alpha by 12'. If you like using setting circles, it is at 8h 48.3m and 12° 0'. It is a small compact cluster of 65 stars, 15' across at 6.1 mag. Under ideal conditions both M 44 and M 67 should be visible without optical aid. Both are good binocular objects.
The only labeled galaxy in Cancer on the Skalnate Pleso Atlas of the Heavens is NGC 2775. We recommend a 4Œ" or larger scope for this object since it is 10.7 mag. It is almost on the Hydra-Cancer border. Its position is 9h 07.7m by 7° 15' N. The size is 2.1' x 1.5' and it is an Sa spiral with a PA of 150° . You may have seen the Hooker telescope photo of this neat little object.
For those of you with 6"-8'' or larger scopes, here are a few test objects. They are NGC 2672, NGC 2545, and NGC 2608.
The first is on the opposite side of the Gamma-Delta line as shown on the chart. This spiral at 8h 46.6a and 19° 06' N is 12.2 mag. Its dimensions are 0.4' x 0.3' and its PA is 90° . It will probably appear starlike in your scope. (as each of the next 2 will)
To the northwest of M 44 is NGC 2545, another spiral, at 8h 11.3m and 21° 30' N. The visual magnitude of this Sb spiral is 13.0. The dimensions of it are 1.2' x 0.8’. The PA is 56°.
At the far northern reaches of Cancer is NGC 2608. It is at 8h 32.2m and 28° 38’ N. It has a brightness of 12.8 mag. It is an Sa spiral and 1.7' x 0.7'. Its PA is 40°. This is west of Iota Cancri as seen on the finder chart.
We encourage you to make drawings and tell us if you find any of the harder objects.
VARIABLES (8) Jon Buchanan
BOOM/#!#; - & $ $ # " / « ¥ # $ # ! ! ! ! ! ! ! ! ! ! ! ! That’s about the only way I can think of to introduce the subject of novae. Over two hundred of these violent events have occurred in our galaxy, and have been seen! Observations of a nearby galaxy, M 31, has led astronomers to believe that about 25 such events occur every year in our galaxy, but due to interstellar dust we see very few.
A light curve for a typical novae is, as can be seen in the illustration (below), a fast rise in one or two days to several magnitudes below its peak value. It pauses for a short time then quickly reaches its peak, after which it will start to decline, rapidly at first, and then more slowly. After about 3 or 4 magnitudes' decrease it starts to oscillate for a while as it continues to fade. This oscillation eventually stops and the star continues to fade smoothly until it has returned to its former luminosity. Its total rise has been around 12 or 13 magnitudes.
Supernovae. Stars that can at peak light, equal and surpass the total light output of the galaxy they are in! These events are to say the least, rare, and only 3 have been reported down through the ages. With modern techniques some 200 have been observed in other galaxies. These superfireballs may get to -14, and a few ultrasupernovae may climb to -16. These ultras occur about one to every five normal supernovae, with one appearing every century. A distribution of about one supernova for every few thousand novae seems to be the observed ratio.
Needless to say, such a violent explosion removes an appreciable amount of the star’s mass, which will inevitably form a cloud. The three observed novae have such clouds. One is the Crab Nebula, formed from a supernova back in 1054 AD, Unrecorded supernova remnants have also been found, such as the Cygnus loop. All are strong radio emitters.
Several dozen stars, P Cygni types, eject matter continuously at low velocities of about 150 km/sec, as compared to velocities ten times this in nova explosions. These stars are hot and very luminous, about -4 in absolute magnitude.
But there are hotter stars in our galaxy, stars that come at the top of the list, Wolf-Rayet stars, of spectral class W. With absolute magnitudes around -5, these stars spew off gas at 3,000 km/sec. (1% velocity of light!) About 200 are known and are spectrally divided into WC - stars with emission lines of highly ionized carbon and oxygen, but no nitrogen; and WN - stars with highly ionized nitrogen emission lines, but no carbon or oxygen. Many are also binaries.
While the clouds, or shells of matter of these stars are not visible, there is a category of other spherical objects visible in the sky, Planetary nebulae. These coloured discs, green due to emission lines of doubly ionized oxygen, number about 1 ,000. The Ring Nebula in Lyra is one famous example of a planetary. Approximately one star in every million is surrounded by these planetary nebulae, remnants of novae.
The Crab Nebula contains an object that will be taken up next: the pulsar which is thought to be the remnants of the star itself.
Dr. Costain discussed some new techniques in the field of radio astronomy at the March center meeting. He works at the Dominion Radio Astrophysical Observatory at Penticton, British Columbia, where the use of interferometers to suit the size aperture of large effective resolving power has proven very valuable.
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Since Tom Tothill will no longer be in Ottawa, and since his new duties in Vancouver will take up considerable time, it would be difficult for him to have continued as Editor of Astronotes. Despite any previous announcements that have been made, I have now taken over that duty which Tom has been so proficient in during the past few years. This is my first issue but not last, and with your support Astronotes will continue to be great.
Here are some coming events: -a graze of Vesta on May 5. Line passes near NMO.
-toward the end of May there will be an interesting configuration of Mars, Jupiter, and last quarter Moon in the morning sky.
-a newly discovered comet, now 15th mag. in Canis Minor, will reach 1st mag. or better by the end of the year.
-articles for the next issue of Astronotes are due by May 18.
Corollary 1 .1 of Murphy's Law states that the number of scratches on a mirror surface is numerically equal to the degree of correction expressed in percent.
# # # # # # # # # We now continue with what may never end:
The pre-nova star is a subluminous blue star of about absolute magnitude 4. It could become a "fast” nova, brightening to about -8 absolute magnitude, decline quickly to its original magnitude in several years' time, or it could be slow and rise to about -6 absolute magnitude, and slowly decline to original brightness in a century.
Spectral observations of novae can be explained by a series of clouds of matter that expand from the star, each one moving faster than the one before. The first consists of the blown off photosphere which, due to its speed and expansion rate, does not have enough time to cool off that gives, in effect, a larger area of equal energy density to that of the star before. This causes the brightening. Eventually these clouds, or rather shells, become so thin, each having less mass than the previous one, that only the star is visible. These shells, however, are still present and have been observed.
A sub-class of novae is Recurrent Novae, of which about six are known. These stars have fast rises in luminosity of about 8 magnitudes and slow declines. They occur every few decades or so and are hot blue stars, located below and to the left of the main sequence, between it and the white dwarfs. It appears that they may be evolving into white dwarfs through a decline in energy from the loss of mass which they expel at each burst.
The reason behind the explosions' occurrences is still unknown, though there are several theories. One comes from recent observations that a large fraction of these stars are members of close binaries with periods of several hours. Stars orbitting this closely will exert strong tidal forces on each other, with the possible result of mass transfer, mass literally being pulled from one star to the other. In such a case, the extra mass of one star could upset its normal energy production enough for it to blow off its surface layers. This is one explanation based on the assumption that since a number of binary systems exist for novae, that all novae may be members of a binary system. But they may not be, and so the theory is advanced that novae result in the normal life cycles of stars. Here then are two explanations of why novae errupt, one dealing with external causes and one with internal causes. It may be that neither is right.
Let us now move on to bigger (if not better) stars, the
"About-face in thirty minutes. How about a coffee?" said Kerrins through the System.
Schlossing had been studying Planet X through the TwoPoint-Four, marvelling at the colour gradation from green at the receding edge to violet the other side. He thought the rapid spin might have something to do with the fact that he didn’t seem to be able to get a decent focus no matter how hard he tried. The detail visible was practically nil.
Anyway, he had his coffee before going back to the little telescope for a few more minutes. When he did, he at first blinked, then rubbed his eyes, then said"Holy Charisma" a couple of times before collecting his wits and adjusting it to "Qu’est-ce aue c’est que ca?", hurriedly ticking the book and dashing back to the scope.
Planet X was going gibbous as he watched! Well, not exactly, perhaps. It reminded him more of the negative of his lunar eclipse picture, but not quite that either. The fact was, and he had better face it squarely, that he was looking at an utterly new phenomenon and his report had better be accurate and objective. There was Planet X, one quarter gone already, the violet edge having disappeared. The edge of the disappearing part was absolutely hard and sharp; in other words it would reach the poles before it reached the center. Where it fell off the disc there was no rounding whatever, just a hard corner.
Schlossing talked the whole thing into the tape recorder as the darkness spread across the planet slowly, majestically, and inexorably. When only a sliver was left he stated, incredulously, that he could see a star where Planet X ought to be, then two more.
So saying, Planet X flickered out, gone from the face
of the Universe in a green flash. "About-face!", said the System cheerfully.
Ms . Rosemary Freeman
National Secretary
The Royal Astronomical Society of Canada
252 College St., Toronto 130, Ontario.