Canopus
April 1997

The Monthly Journal
of the Johannesburg Centre of the
Astronomical Society of Southern Africa
Box 93145 Yeoville 2143 - 18a Gill Street Observatory

Monthly Meeting

Notice is hereby given that the monthly meeting of the Johannesburg Centre will take place at the Johannesburg Planetarium on Wednesday, 9 April 1997 at 8pm sharp. Please note that this meeting will be held in the PLANETARIUM and not at the Sir Herbert Baker Library. Tom Budge will talk about Constellation Recognition.

Beginner’s Course

Tom Budge will host a special beginner’s course in the Planetarium at 7pm sharp.

Future Topics

MAY - Measuring the Mass of the Sun by Eben van Zyl.

JUNE - A History of the Universe by Basil Payne.

JULY - Annual General Meeting

 

Events

5 JULY - Weekend Star-party in Swinbourne organised by Ed Finlay. This is a repeat of the famous and most enjoyable weekend held some years ago. Many will remember it as the coldest viewing session of all times with night-time temperatures around minus eight degrees Celsius! Prices and other details will be published in due course.

POSSIBLE FUTURE - Visit to SAAO (South African Astronomical Observatory) at Sutherland to be organised by Trevor Gould.

Diaries of an Astro-amateur

by John Maher at jmaher@icon.co.za

Firstly apologies, The map I sent in last month of the HALE-BOPP comet positions were for this month, not last month, and you should be looking North West. Well, what a lousy month for star gazing. The sky was almost permanently filled with that white and Grey fluffy stuff that seems to accumulate in front of new telescopes. Murphy’s law of course states that the chance of cloud covering the sky when you want to look at the stars, is proportional to the cost of the telescope and how long you have had it.

So I didn’t get much opportunity to see the heavens , therefore I will recount a titbit of information I came across about Tycho Brahe, I found this info in a Readers Digest publication, and I have paraphrased it a bit.

Tycho Brahe was a Danish Nobleman who was born in 1546. He could never accept the idea that the earth moved around the sun and intended his lifelong work to prove the Ptolemaic theory correct. Despite this flaw in his thinking, he became the greatest observational astronomer since Aristarchus. When Tycho was 30, the King of Denmark made him landlord of his own island in the Baltic called Hven. From this lonely base and using only a giant quadrant (a monstrous protractor), he made a 20 year long study of the heavens, and produced a wondrous star catalogue, with thousands of accurate fixes on the changing positions of the planets against their background of the stars. Tycho allowed nothing to interfere with his work , particularly a shortage of cash. To ensure that the islanders paid their taxes, he had a prison built into the observatory, and anyone who threatened to default on payment of his taxes, was promptly locked up.

Eventually the constant protest of the Hven islanders about the threat of prison prompted the Danish King to withdraw his support, and Tycho went to live in Prague where he engaged a new assistant called Kepler.

Now, wouldn’t it be great if our government could fund a bit of astronomical research in this manner.

Give us an island or something.

Well hopefully next month will be better astro-wise, I still want to see if I can see the UFO that is hiding behind HALE-BOPP <GRIN>.

Observing Adventure

by Basil Payne

It was a dark and stormy night. This was Johannesburg.

About a month ago Casper Labuschaigne was going to visit family in the Free State and suggested we use the opportunity to do some star viewing.

Before we left on Friday at about 6 pm, we telephoned ahead and were told that the sky was clearing rapidly (and we believed it!). Our viewing destination was Clarens, about 20 kms from the Golden Gate Highlands National Park.

The journey was uneventful, except that the only lights we could see came from the traffic and not from the sky. However, when we arrived at about 9 pm, there was a definite clearing in the sky and all looked good. We had planned to stay up as late as possible to make as much use of the opportunity of clear skies.

There are two establishments in Clarens, next to each other, which offer a bar, dining and accommodation. In order to properly prepare for the evening’s viewing, we started with the bar at the first establishment and then proceeded to the other for dinner. Now to the viewing spot! This was just outside the National Park, but after entering the accommodation area. It was a high spot and the roads winds forever before you reach the top. From this vantage point we could see the cloud cover as it was lit by the lights in the accommodation area (I think). Unfortunately the cloud cover was moving rapidly and filling with more and more cloud and showing no sign of clearing. If anything it was getting worse and a wind had come up. After waiting for about 45 minutes we gave up and headed back to Clarens. We checked into one of the establishments and decided to give it to 12:30 am for the sky to clear. Every ten minutes or so we surveyed the sky. There would be the occasional clear patch, but it would close up again. Suddenly at midnight, the sky started clearing rapidly. We headed out of Clarens and as soon as the town lights had disappeared, we drove off the main road onto a farm road and then parked on the side of the road.

It was a moonless night.

By the time I had set up my 8 inch Celestron Schmidt-Cassegrain, the sky was perfectly clear. It took some time to come to terms with a sky which had no light pollution and you could see the incredibly bright milky way right down to the horizon. Just after the sky cleared, the stars were twinkling at an enormous rate and the seeing was very bad. As time passed, the seeing improved and details were much easier to make out.

We looked at a number of familiar objects and some new ones. For the first time I saw the Tarantula nebula in the Large Megellanic cloud and the coal sack was also clearly visible. Mars was quite high in the sky and very bright. Unfortunately the seeing did not help and Mars only appeared as a red ball. Before we gave up at about 3 am we decided to look at the great nebula in Orion. By this time Orion had almost set and was very close to the horizon. Nevertheless, it was far brighter than I had ever seen it from Johannesburg.

The moral of the story? For those of you who have never seen a really dark sky it is certainly worth the effort.

Planetary Systems

from Nature 386, 17 (1997)

Many very young stars are surrounded by dusty disks, perhaps the beginnings of planetary systems. Until now, only one such disk has been found around a main-sequence star (a star that has reached the stage of stable hydrogen fusion in its core). Now another candidate has been found, around a massive binary pair of stars. So planets may be able to form in binary systems too.

Structures in the Mirror Universe

from THE ASTROPHYSICAL JOURNAL, 478:2938, 1997 March 20

The idea that our present universe may have a mirror partner evolving with identical or very similar matter and force content has been invoked for various reasons from time to time during the past 30 years. The continuing interest in such models was revived in the late eighties by the observation that the superstring theories lead naturally to such a picture where the known particles are accompanied by a duplicate set, but in which the two sets have little or no interaction except for that of gravitation. Most recently this idea has emerged from attempts to understand the experimental observations relating to the mass of neutrinos.

One such model, the weak asymmetric mirror model, has features of particular astrophysical interest:

no mirror element, except hydrogen, is stable; the mirror proton mass is similar to that of the normal proton; and the mirror electron mass is perhaps 10 -100 times heavier than that of the normal electron, while the value of mirror electric charge is the same as for normal matter. If mirror matter exits, it might be detected by lensing or other gravitational phenomena, based on the mirror structures that might form, such as supermassive mirror black holes. These ideas are still very speculative and depend on the outcome of future neutrino experiments. However, given the current data, the mass of the mirror electron can be no greater the 50 times the mass of the normal electron.

Time to trap an Ytterbium Ion

from Nature 386, 225 (1997)

We may soon have vastly more accurate atomic clocks. One atomic transition in ionised ytterbium has a natural lifetime of ten years, making the photons it emits on decay perhaps the most nearly monochromatic in the visible range (according Heisenberg’s uncertainty principle relating time and energy). Its frequency is being pinned down by researchers who have trapped a single ytterbium ion, and excite it into making the transition by scanning a laser beam across the range of frequencies where the line is expected. A clock based on this transition could be accurate to one part in 1018, 1,000 times better than modern caesium atomic clocks.

Farsighted Gravity Lens sees Stars

from Science 1997

Most stars are so distant that, even through the largest telescopes, they look like simple points of light. Now, by using the gravity of one star as a magnifying glass, a multinational team of astronomers has been able to pick out features on the face of a second star 30,000 light-years from Earth.

Quotes on the Nature of the Universe

from an e-mail message by Dave West

Carl Zwanzig: "Duct tape is like the Force. It has a light side, a dark side, and it holds the universe together...."

Douglas Adams: "There is a theory which states that if ever anybody discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened."

Albert Einstein: "Only two things are infinite, the universe and human stupidity, and I’m not sure about the former."

Unknown: "Astronomers say the universe is finite, which is a comforting thought for those people who can’t remember where they leave things."

Edward P. Tryon: "In answer to the question of why it happened, I offer the modest proposal that our Universe is simply one of those things which happen from time to time."

John Andrew Holmes: "It is well to remember that the entire universe, with one trifling exception, is composed of others."

Max Frisch: "Technology is a way of organizing the universe so that man doesn’t have to experience it."

Kilgore Trout: "The universe is a big place, perhaps the biggest."

Woody Allen: "I’m astounded by people who want to `know’ the universe when it’s hard enough to find your way around Chinatown."

Douglas Adams: "In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move."

William J. Broad: "The crux... is that the vast majority of the mass of the universe seems to be missing."

Rich Cook: "Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning."

Fred Hoyle: "There is a coherent plan in the universe, though I don’t know what it’s a plan for."

Ray Bradbury: "We are an impossibility in an impossible universe."

Christopher Morley: "My theology, briefly, is that the universe was dictated but not signed."

Edward Chilton: "I’m worried that the universe will soon need replacing. It’s not holding a charge."

Calvin and Hobbes (Bill Watterson): "The surest sign that intelligent life exists elsewhere in the universe is that it has never tried to contact us."

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Rudolf Graspointner
Geyerstr. 11
D-80469 Munich
GERMANY
24.03.1997

Hi Thomas,

On my visit to JHB last August we only briefly met and I commented that my telescope would come onto the market. This is now the offer for anyone interested and hope that it will be posted on the club’s notice board or in the newsletter. I have little idea of the current prices there, but should you feel that the price is low I have nothing against the equipment being resold by the society, or being raffled, at a profit.

My offer is this:

CELESTRON C8 CLASSIC TELESCOPE & ACCESSORIES

. telescope f10 lens / 8-inch / fl 00mm

. heavy-duty adjustable tripod

. equatorial-mount with motor-drive

. three eye-pieces ( 9mm, 18mm, 25mm )

.12V car-adapter

. three camera adapters ( OLYMPUS, Mi-alpha-7000, TPS )

. piggy-back camera mount

. instruction manual

. GOOD CONDITION

. FULLY OPERATIONAL

. ONLY 9 YEARS OLD

. ONLY ONE USER

SALE PRICE: R 6 500 + GST or best counter-offer

(new price around R15000?)

ON VIEW AT: "CAS CAMERA"

6 Progress House
Corner Maxwell Ave. & Bordeaux Drive
RANDBURG

Ask for "Chris" or "Mrs. Cas"
Tel: (011) 789-2720

The same offer can be made country-wide next month (if needed).

I am available at tel: (0949-172) 3425656
or (094989) 2011161 (after-hours)
although CAS CAMERA have full authority to sell

Regards to all from Munich and good viewing