The Astronomical Society of Edinburgh

Journal 41 - April 2000

Cover picture - Lorna McCalman

Lorna McCalman - President

From the President - Lorna McCalman 2
A Note from the Secretary 3
Science Festival 3
Observations 3
Book Review - "Collins Wild Guide - Night Sky" by Storm Dunlop 4
A 16th Century French Poet on Astronomy - Graham Rule 5
The Moon Illusion Explained? - Steuart Campbell 8
The Society's Library 9
Where Have All the Stars Gone? - Grant Wilson 10
Book Review - "Patrick Moore's Millennium Yearbook" by Patrick Moore and Allan Chapman 11
Scottish Astronomers' Group Meeting 11
Scottish Astronomy Weekend 12
The Shuttle Over Edinburgh - Dorothy Mackie 12
Professor Hermann Brück 13
Mr J I Dodds & Mr J D Weir 14
Crossword - Dave Gavine 15
Why Not Name A Star? (Advertisment) 16
Observing Variable Stars - Ron Livesey 18

 

Published by
The Astronomical Society of Edinburgh
City Observatory, Calton Hill, Edinburgh
for circulation to members

Editor: Dr Dave Gavine
29 Coillesdene Crescent, Edinburgh
Assistant Editor: Graham Rule
Website: http://www.roe.ac.uk/asewww/

From the President

From April Fool's Day the Council of the Society elected at the AGM took office and there have been more than the usual number of changes in its composition. Alan Ellis has handed over the President's medallion after caring for it, and the Society, over a busy two years. Jim Nisbet has handed over the Treasurer's cheque book after nine years looking after the Society's money. Johnnie Bradley has stepped down as Vice President. I am sure that members will join me in thanking them for all the work they have done. But we have not seen the last of them as they are all continuing as Councillors and I am sure that those who have stepped into their places will look forward to benefitting from their experience. Of the Officers only Graham Rule is continuing in the same post as nobody else seems particularly eager to displace him.

The new Council comprises:

President: Mrs Lorna McCalman  
Vice Presidents: Dr Duncan Hale-Sutton Mr Charlie Gleed  
Secretary: Mr Graham Rule    
Treasurer: Dr George Grant    
Councillors: Mr Johnnie Bradley Mr Alan Ellis Mr Ray Fenoulhet
  Mr Peter MacDonald Mr Jim Nisbet Mr Adrian Weatherhead

The Society's Council is there to 'manage the property, proceedings and affairs of the Society' and, as such, has to make any decisions regarding how the Society works. But that is not to say that we are not open to suggestions or that the Society's activities are only those done by Council Members. We have to thank Jim Douglas and Kenny Laidlaw for doing a great deal with our Earlyburn observing site. Neil Grubb has sparked off interest in a new group dealing with CCD Imaging which has met on a couple of occasions at the Observatory and we hope to get some of their results on the Society's web site soon. So you don't have to be on the Council to boost the Society's activities - we are always open to suggestions!

Volunteers from the Council open the Observatory every Friday night (even when there isn't a meeting planned - and even when it is cloudy). We welcome members and visitors who want to pop in for a chat or a look through the Cooke telescope. But it is sometimes difficult for the Council Members present to operate the telescope, show people around, and get on with managing the Society. Part of the problem is that only a few members actually know how to use the Cooke telescope and I have asked Graham Rule and George Grant to write some notes on using it. Members who would like to be taught the (fairly simple) controls and procedures should speak to me, George or Graham. We would particularly welcome members who could not just use the telescope but conduct visitors around the observatory and the sky.

Once again there are a number of events related to Astronomy in the Science Festival. Of particular interest are the Open Days at the Royal Observatory on April 14 (6pm - 9pm) and April 15 (2pm - 6pm).

Our Summer programme starts with Neil Grubb speaking about CCD Imaging (April 7) and Brian Kelly (May 5) who will talk about sunspots. The Scottish Astronomers' Group meets at the Observatory on May 20 (see later in this Journal). The Summer Syllabus Card should be available soon and Graham tells me that he is doing what he can to finalise its content.

Please remember that the Officers and Council of the Society are elected to look after the interests of all the members but we cannot do everything ourselves. If you can help in any way (no matter how small) please volunteer your services.

Lorna McCalman

A Note from the Secretary

As semi-official archivist/historian for the Society I would like to take this opportunity to note that Lorna is the first ever Lady President of the Society. We have had ladies on the Council of the Society on a number of occasions (including the Founding Council in 1924) but have never managed to persuade them to take on the task of trying to keep the Council running smoothly, preside at meetings and all the other things the President does behind the scenes. (Lorna might well suggest that 'persuade' should be replaced with 'bully' in that last sentence.) I am sure that members will offer our congratulations to Lorna in her new post.

Graham Rule


Science Festival

There are a number of events in the Science Festival this year which may be of interest to members. Here is a short selection:

Mars - the Once and Future World
Heather Cooper
Royal Museum, Saturday 8th April, 6pm
Astrophysics and Cosmology of
the 21st Century
Professor Malcolm Longair
Royal Museum, Saturday 6th April, 8pm
Life of the Cosmos
Professor Lee Smolin
Royal Museum, Sunday 9th April, 8pm
Sunshine, Solar Storms and Us
Professor John Brown
David Hume Tower (Lecture Theatre B), Monday 10th April, 5:45pm
Celestial Real Estate
Professor Ian Stewart
Royal Museum, Monday 10th April, 6pm
Cosmic Natural Disasters - Friend or Foe?
David Hume Tower (Lecture Theatre B), Tuesday 11th April, 5:45pm
Professor John Brown
The Physics of Star Trek
Professor Lawrence Krauss
George Square Theatre, Wednesday 12th April, 7pm
The Creation of the Universe
Professor Joseph Silk
George Square Theatre, Thursday 13th April, 6:30pm
Origins of Our Universe
Professor Malcolm Longair
Royal Museum, Friday 14th April, 6pm
Volcanoes, Meteorites and Megadeath
Dr Sue Rigby
David Hume Tower (Lecture Theatre B), Sunday 16th April, 6:30pm
Royal Observatory Open Day
Friday 14th April, 6pm - 9pm
Royal Observatory Open Day
Saturday 15th April, 2pm - 6pm

Observations

Despite the obviously active Sun and a lot of flare- and mass- ejection reports from NOAA and other sources, the Big Aurora has still to happen. Comparing this year with ones before solar maxima in the past, e.g. 1978, it should all be happening. An active rayed display was visible on January 22/23 but only just - it was swamped by bright moonlight. A weak diffuse rayed band was seen very low at Joppa on February 5/6. The total eclipse of the Moon on January 20/21 was well seen in a perfect sky, and made the local and national papers. Lorna successfully timed the occultation by the Moon of zeta Geminorum on March 14. Meteors: Dave Gavine saw 31 Geminids, none of them very bright, in one hour in the early morning of Dec 13/14 through thin cloud, then on Jan 3/4 he got only 13 Quadrantids in ¾ hour in a rapidly deteriorating sky (and Ron Livesey saw 7 under the same conditions). Unfortunately later this year all the major showers. except the Taurids, will be affected by bright moonlight.

Front cover of book

Collins Wild Guide - Night Sky
Storm Dunlop & Wil Tirion

Collins Natural History (HarperCollins), London, 1999;
255 pages
ISBN 0-00-220127-5
£7.99

First impressions on picking up this book are that it's a good 'handy' (inside coat pocket-sized) introduction to practical astronomy, aimed at the enthusiastic amateur like myself. However, on closer inspection (on a trip at the end of last year out to a beautiful light-pollution free clear sky area of France), I quickly realised that this was a bit more than your average guide, and indeed I feel this book should be a required buy for many of us!

Much time and thought has gone into its format, and it has a sewn binding and hard-wearing protective plastic cover which is 'must' for any modern hand-book intended for field use.

Inside, Storm Dunlop has given the reader an excellent practical introduction to the night sky with good advice and tips for the newcomer, including an invaluable section on choosing and buying a set of binoculars. Now, while wandering around car boot sales, I find myself looking at binoculars to try out Storm's simple tests assessing alignment and quality of the optics just for fun! Clear teaching of the 'star-hopping method' for learning your way around the sky is followed by Wil Tirion's excellent monthly sky charts. These are cleverly combined with photographs of the major constellations, which allows the frequently cloud-bound Edinburgh reader to practise observation from the comfort of an armchair while awaiting that important parting of the clouds!

Once you have learnt your way around the sky, more detailed charts show every major constellation on a page-by-page basis. These are combined with individual fact-files to point you to all the objects of interest in the region worth observing, such as nebulae, open and globular clusters, double and variable stars and galaxies. This is an invaluable reference section for even the more experienced amateur.

Moving on to observation of the planets, clear charts are again used together with diagrams of where they appear with respect to the horizon to assist location. Planet positions are shown for up to and including year 2003.

The real gem of a section though, is that devoted to introducing the moon and the delights of selenography (the study of the moon). Superbly detailed 2/3 page photographs show the moon as it moves through its phases, and the accompanying maps allow you to easily find your way around our closest and much admired space neighbour. In my opinion, this in itself is worth buying the book for, as the photos are realistic to the scale seen through a good pair of binoculars.

Finally, details of forthcoming astronomical events are tabulated together with good general descriptions of other atmospheric phenomena. A few of the photos in this section will be easily recognised, as they are by Dr Dave Gavine.

In conclusion, this book is an excellent value-for-money buy for any of you budding amateurs out there who want a sturdy, well-written and practical introduction to the night sky. For those of you who feel you already know the sky well, it should also be considered as a handy no-nonsense field guide, to be taken out to Earlyburn with a challenge to view and identify not only the fainter astronomical beauties, but also the gegenschein (see the book!).

Will B. Joy

A 16th Century French Poet On Astronomy

The "Divine Weeks and Works of Guillaume de Saluste, Sieur du Bartas" was published in 1592 (in Shakespeare's heyday) was a collection and translation of Du Bartas' writings by John Sylvester (1562?-1621). Du Bartas was a protestant Gascon who, in 1579, wrote an epic 'sacred' poem about the first seven days from the book of Genesis. Readers may be interested in some of his thoughts about the fourth day in which (according to Genesis):

And God said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days, and years: And let them be for lights in the firmament of the heaven to give light upon the earth: and it was so. And God made two great lights; the greater light to rule the day, and the lesser light to rule the night: he made the stars also. And God set them in the firmament of the heaven to give light upon the earth, And to rule over the day and over the night, and to divide the light from the darkness: and God saw that it was good. And the evening and the morning were the fourth day.

Genesis I, 14-19

The Moon and Eclipses

Du Bartas has a long section addressed to the Moon in which he recognises that it does not really change in size through the month and that it is "Round as any ball" that reflects light from the Sun. There is a somewhat romantic description of the Moon's changes as it gets closer to the Sun and then moves away from it. But he is clear that half of the Moon is always lit up - it is just that sometimes the lit part faces the heavens rather than the Earth.

O second honour of the Lampes supernall,
Sure Kalender of Festivals eternall,
Seas Sov'raintesse, sleepe-bringer, Pilgrims guide,
Peace-loving Queene: what shall I say beside?
What shall I say, of thine inconstant brow,
Which makes my braine waver I woat not how?
But, if by th'eye, a mans intelligence
May guesse of things distant so farre from hence,
I thinke thy body, Round as any Ball,
Whose superfice nigh equall over all,
As a pure Glasse, now up, and downe anon,
Reflects the bright beames, of thy spouse, the Sunne.
For as a Husbands Noblesse doth illuster
A mean-borne wife: so doth the glorious lustre
Of radiant Titan, with his beames em-bright
Thy gloomie Front, that selfly hath no Light.

Yet 'tis not alwaies after one selfe sort,
For, for thy Carr doth swifter thee transport
Then doth thy brothers, diversly thou shinest
As more or lesse thou from his sight declinest.
Thearfore each month, when Hymen blest, above
In both your bodies kindles ardent love;
And that the Starres-King all inamour'd on thee,
Full of desire, shines downe direct upon-thee,
Thy neather halfe-Globe toward th'Earthly Ball,
After it's Nature, is obscured all.
But, him a-side thou hast no sooner got,
But on thy side a silver file we noat,
A halfe-bent Bow, which swells, the lesse thy Coach
Doth the bright Chariot of thy spouse approach,
And Fils his Circle, when th'Imperiall Starre
Beholds thee just in one Diameter.
Then, by degrees thy Full face falls away,
And by degrees Westward thy Hornes display:
Till fall'n againe betwixt thy Lovers armes,
Thou wink'st againe, vanquisht with pleasures charmes.

Thus doost thou Waxe and Waine, thee oft renuing;
Delighting change: and mortall things ensuing
(As subject to thee) thy selfes transmutation,
Feele th'unfelt force of secret alteration.

Not, but that Phoebus alwaies with his shine
Cleeres halfe (at least) of thine aspect devine;
But 't seemes not so: because we see but heere
Of thy round Globe the lower Hemisphear:
Through waxing us-ward, Heav'n-ward thou dost waine
And waening us-ward, Heav'n-ward grow'st againe.

 

Most of us have seen a lunar eclipse. Often the Moon turns a dark red as it is lit by a ring of sunsets and sunrises around the Earth. We don't get lunar eclipses every month because the lunar orbit is slightly tilted to the ecliptic. Only when a full Moon coincides with it crossing the ecliptic does it pass into the Earth's shadow.

Yet it befalles, even when thy face is Full,
When at the highest thy pale Coursers pull,
When no thicke maske of Clouds can hide away
From living eyes, thy broad, round, glist'ring ray,
Thy light is darkned, and thine eyes are seeld,
Cov'red with shadow of a rustie shield.
For, thy Full face, in his oblique designe
Confronting Phoebus in th'Ecliptike ligne,
And th'Earth betweene; thou loosest for a space
Thy splendor borrowed of thy Brothers grace:

Du Bartas then describes solar eclipses in which the Moon gets its own back on the Earth for cutting off the sunlight. The Moon places itself between the Sun and the Earth making the Sun appear to be 'light-les'. Of course, the Sun itself isn't really changed at all. So lunar and solar eclipses are completely different in character.

But, to revenge thee on the Earth, for this
Fore-stalling thee of thy kinde Lovers kisse,
Sometimes thy thicke Orbe thou doo'st inter-blend
Twixt Sol and us, toward thy later end:
And then, because his splendor cannot passe
Or pierce the thicknes of thy gloomie Masse,
The Sunne, as subject to Deaths pangs, us sees not,
But seemes all Light-les, though indeed he is-not.


 

 

Thearfore, farre diff'ring your Eclipses are;
For thine is often, and thy Brothers rare:
Thine doth indeed deface thy beautie bright,
His doth not him, but us bereave of Light:
It is the Earth, that thy defect procures,
It is thy shadow, that the Sunne obscures:
East-ward, thy front beginneth first to lacke;
West-ward, his browes begin their frowning blacke:
Thine, at thy Full, when thy most glorie shines,
His, in thy Waine, when beautie most declines:
Thine's generall, towards Heav'n and Earth together;
His, but to Earth, nor to all Places neither.

For Astrology

While his knowlege of astronomy is reasonably good for his time Du Bartas does reflect the comtemporary astrological views. For example, he equates eclipses with disasters and the phases of the Moon with "our mindes and humours" along with various influences of stars and constellations.

Against Copernicus

He rejects the Copernican world view, describing its supporters as "Brain-sick". He shows some good reasons for this. After all, the Earth doesn't feel as though it is moving or turning. Copernicus was only one of many who came up with models that tried to 'save the appearances' and match apparent motion of the heavenly bodies to a theory. (The translation mentions Copernicus by name while Du Bartas only says "ce docte Germain".)

As th'Ague-sicke upon his shiv'ring pallet,
Delays his health oft to delight his palate;
When wilfully his taste-les taste delights
In things unsavorie to sound Appetites:
Even so some Brain-sicks live thear now-adaies,
That lose themselves still in contrarie waies;
Preposterous Wits that cannot row at ease,
On the smooth Channell of our common Seas.
And such are those (in my conceit at least)
Those Clarkes that thinke (thinke how absurd a jest)
That neither Heav'ns, nor Starres doo turne at all,
Nor daunce about this great round Earthly Ball;
But th'Earth it selfe, this massie Globe of ours
Turnes round-about once everie twice-twelve howers:
And we resemble Land-bred novices
New brought aboard to venture on the Seas,
Who, at first launching from the shoare, suppose
The ship stands still, and that the ground it goes.

 

So, twinckling Tapers that Heav'ns Arches fill,
Equally distant should continue still.
So, never should an Arrow Shot upright,
In the same place upon the shooter light:
But would doo (rather) as at Sea, a stone
Aboord a Ship upward uprightly throwne,
Which not within-boord falles, but in the Flood
A-stern the Ship, if so the wind be good.
So, should the Foules that take their nimble flight
From Westerne Marshes toward Mornings Light,
And Zephirus, that in the Summer-time
Deliglits to visit Eurus in his clime,
And Bullets thund'red from the Canons throat,
(Whose roaring drownes the Heav'nly thunders note)
Should seeme recoyle: sithens the quicke careere,
That our round Earth should daily gallop heere,
Must needs exceed a hundred-fold for swift,
Birds, Bullets, Winds; their wings, their force, their drift.

Arm'd with these reasons, t'were superfluous
T'assaile the reasons of Copernicus,
Who, to salve better, of the Stars th'apparance,
Unto the Earth a three-fold motion warrants:
Making the Sun the Center of this All,
Moone, Earth, and Water, in one onely Ball.
But sithens heere, nor time nor place doth sute,
His Paradox at length to prosecute:
I will proceed, grounding my next discourse
On the Heav'ns motions, and their constant course.

Conclusion

While there is a lot in his writing that seems odd nowadays I hope that readers will agree with me in supporting Du Bartas when he says:

I oft admire Greatnes of mightie Hills,
And pleasant beautie of the flowerie Fields,
And count-les number of the Oceans sand
And secret force of sacred Adamant:
But much-much more (the more I marke their course)
Stars glistering greatnes, beautie, number, force.

J'admire la grandeur d'une haute montagne,
L'agreable bonté d'une verte campagne,
Le nombre du sablon de l'ondeux element,
Et l'attrayant pouvoir de la pierre d'eymant;
Mais plus des astres clairs j'admire, où plus j'y pense,
La grandeur, la beauté, le nombre, la puissance.

Thanks to Storm Dunlop for bringing Du Bartas to my attention. Storm is currently working on "Glorious Eclipses" which will be published by Cambridge University Press (expected in November 2000)

Graham Rule

Sources

The Divine Weeks and Works of Guillaume du Saluste, Sieur du Bartas
by Joshua Sylvester, edited with introduction and commentary by Susan Snyder
Oxford University Press, 1971 (ISBN 0-19-812717-0) (Volume I)
The Works of Guillaume De Salluste, Sueur du Bartas
by Holmes, Lyons & Linkder
Chapel Hill, The University of North Carolina Press, 1938 (Volume II)

The Moon Illusion Explained?

I last wrote about the "Moon Illusion" in ASE Journal 19 (July 1988), mainly describing the theory of Patrick Rizzo from New York who appears to have been the first to suggest the relative-size hypothesis (as the area of sky round the Moon decreases, it appears larger, usually 2.5 to 3.5 times larger). This hypothesis was adopted by psychologist Frank Restle.

The conventional explanation (see the Editor's comments in Journal 11 and my subsequent article in Journal 14) is that distance cues at the horizon make the Moon seem further away and therefore larger (because we know that if an object of constant angular size is further away it must be larger). However this hypothesis fails to explain why the big low-lying Moon looks closer, not further away. In the 1960s psychologists explained this by suggesting that the eyes tend to focus on foreground objects when viewing a horizon Moon, but relax towards infinite focus when looking at the Moon in an empty sky. The brain interprets the relaxed focus as meaning that the Moon is very distant - and because the most distant objects look small, perceives the Moon also as being small.

Now an article in New Scientist ('Moon magic' 15 January 2000) reports a claim (in Proceedings of the National Academy of Sciences vol. 97 p.500) that the matter has finally been settled in what is described as 'a very decisive and convincing experiment'. Psychologist Lloyd Kaufman and his son James took five volunteers up a hill with a broad view of the horizon. They stood them in front of a large semi-reflecting mirror through which they could see the horizon. In the mirror they could also see the reflected images of four fake moons from a projector. When the volunteers focussed through the mirror onto the horizon, the four moons merged into two, creating two apparently three-dimensional moons. In one set of trials, the two moons appeared on the horizon; in the others they were high in the sky. By pressing a computer key, the volunteers could make one moon of the pair appear to move closer or further away. The computer actually shifted one of the four projected images slightly sideways. This created an apparent change in the distance without changing the size of the image on the retina. For each trial, the volunteers adjusted the position of the moveable moon until it appeared to be halfway between them and the fixed moon.

The result was that they placed the horizon moon 'further away' than the elevated moon. On average they took the horizon moons to be four times as distant as the elevated moons. Lloyd Kaufman concluded that the visual system responds to the horizon Moon as if it were further away than the elevated Moon, just as the conventional hypothesis claims. But this still demands an explanation as to why the horizon Moon appears closer. Aries Arditi, a vision researcher at Lighthouse International in New York City, claims that this stems from a logical thought process that occurs long after our unconcious mind has estimated the Moon's distance, and hence its size. Because the Moon looks bigger, it must be closer. He says 'We can register apparent distance unconsciously in direct contradiction to our conscious experience'.

All this appears to falsify Rizzo's relative size hypothesis. Apparently we see the horizon Moon as further away because all objects on the horizon are known to be at a great distance. Then (Arditi failed to mention this) because our minds know the Moon to be a constant size, they magnify its image to compensate for the perceived greater distance. Then, because it has been magnified, we conclude that it must be closer. Confused?

In a subsequent issue of New Scientist (29 January 2000, Opinion), A. R. Constable claimed that it is easy to remove the signals from the brain by closing one eye and viewing the Moon with the other eye through a small hole, such as that formed with the root of the thumb and the first finger 'When you look at the Moon in this way it suddenly returns to its normal, smaller size and distance'. He went on to describe 'a more interesting and less well-known phenomenon, keep one eye looking through the small hole and then open the other eye to look directly at the Moon.' He claims that the effect is dramatic and that one sees two entirely different sized Moons simultaneously and that, by going cross-eyed, one can play with the two Moons, sliding them together or separating them at will. He claimed that, whatever tricks the brain is playing to create the illusion of a large Moon, it can, at one and the same time, discard them. He strongly urged readers who have not seen this 'extraordinary phenomenon' to look for it within a few days of a Full Moon.

I have not tried this experiment, although I referred to a similar one (looking at the Moon through a tube) in Journal 19. Perhaps readers could try it and let the Editor know how they fare.

[And the Editor will try it too. He is used to being cross-eyed, a useful method of studying pairs of photographs to spot asteroids or novae without a blink-microscope, or to look at stereo pairs. Steuart was one of the unfortunate eclipse chasers in August, being clouded out in France. He points out that Graham Young (last Journal) has slipped up in saying that it was the last eclipse of the Millennium]

Steuart Campbell


The Society's Library

As members will know, the Society's Library has been in a rather disorganised state since it had to be moved from the Playfair Building to the City Dome when dry rot was found in some of the shelves. I have been trying to rectify this situation and hope that by the time this edition of the Journal appears I will have completed the first stage of reorganisation.

Most of the books are in a single sequence sorted alphabetically by surname of (first named) author. The majority of these are available for borrowing by members although a few are marked as being for reference only. There are also a couple of glass-fronted cabinets containing other books which should not be removed from the Observatory.

I have produced a list of our books on my computer and have printed extracts of this to form Author and Title catalogues. These will be kept along with the books so should come in useful if you want to check whether the Society has a particular title.

As part of the computerisation each volume has been given a six character identifier (eg ABCD01) and I have stuck a 'postit' note inside each book. If you are borrowing something that has such a note then please copy this code into the borrowing book. (Please try not to lose the postit when you have the book out.)

The next phase of the reorganisation is for me to finish adding Dewey Decimal classification into the computer after which I will be able to print more permanent labels and mark the spines with the classification. Then I will re-order the books on the shelves by classification (and hence by subject) and print a Subject catalogue to join the others.

Hopefully I will get this done before another three years are over.

By the way, I still do not know when the City might get around to doing the repairs in the Playfair Building that have been planned for so long. I will let members know as soon as I have anything to tell them.

Graham Rule

Where have all the stars gone?

Olbers' Paradox Explained

In 1826 Heinrich Olbers posed the question "why is the sky dark at night?"

Olbers assumed that the Universe in which we live is infinite in size, populated by an infinite number of stars that are evenly dispersed and static. From this model of the Universe it is assumed that when looking into the night sky, no matter which direction you choose to look, your line of sight would meet a star.

If this is the case, where are all the other stars?

Lets look at this another way - Isn't light from a distant star harder to detect than a nearer one? Surely this would explain the paradox?

True, light received from a distant star is harder to detect, but in Olbers' model of the universe there are more stars at the greater distance. Therefore, although the light received from a distant star is less than a closer one, this is compensated by there being more stars at larger distances.

But the sky is still dark!

What about interstellar dust - wouldn't this absorb starlight and therefore obscure all but the brightest or closest stars?

Yes, dust does absorb light, and in so doing obscure stars, but over a long period of time this absorption will cause the dust to heat up. Were it not for the fact that it will evaporate, we could expect it to continue to heat up until it, too, begins to shine as brightly as the stars that it obscures.

But the sky is still dark!

To resolve this paradox we must leave behind this 19th century view of the Universe and look to 20th century cosmology.

We know from observations of redshifts that all galaxies are moving away from us. The farther away a galaxy is from us, the faster it recedes from us.

Now if we look at the Universe in reverse, we would see all the galaxies rushing towards each other until they all arrive at the same place at the same time in a Big Crunch. From this we know the Universe began from a single point, and has been expanding ever since.

This rate of expansion proves useful as from it we can estimate the age of the Universe, which is thought to be between 10-17 billion years.

So how does this resolve the paradox? Well, we know the Universe has a finite age and rather than being static, is in fact expanding. Light travelling to us from these distant stars becomes redshifted. That is to say the photons travelling to us lose energy, resulting in the light from the star not being as bright as when it was emitted.

As the Universe is not infinitely old, the maximum distance that light could have travelled to us is about 15 billion light years. Any object that lies outside this radius is outside the observable Universe. Therefore, when someone on Earth looks up into the night sky, his or her line of sight may meet a star, but should that star lie beyond the observable Universe, its light has yet to reach us, leaving that part of the sky dark.

Grant Wilson

Patrick Moore's Millennium Yearbook
by Patrick Moore and Allan Chapman

Springer Verlag, London, 2000;
Paperback, pp.99;
ISBN 1-85233-619-6;
£9.95

Much has been written and argued about the Millennium was it or wasn't it. This delightful book is different. It is about the last Millennium, i.e. the year AD 1000, or if you prefer it, 1001. The authors have compiled an amusing compendium on the state of Astronomy at that time, and there are many interesting nuggets of information hidden amongst the fun. Most of all I like the clear explanation of how the Astrolabe worked. Most writings on this medieval device are lengthy and abstruse. We are shown maps of the night sky for the year 1000, as seen from Ethelred II's capital, Winchester, then a collection of reports in the chronicles of "marvels" seen in the heavens, eclipses, the aurora (fiery dragons) and comets - the hairy stars warning of disaster. Then we are given an account of the Ptolemaic system of the Universe and of the properties of light as known then, and a review of the contemporary instrumentation: sighting devices, sundials and the rudimentary clock. The authors conclude by contemplating on what the next thousand years might bring.

Front cover of book

Ptolemy, Al Sufi, Alhazen, Abul Wafa and other learned men of the time appear, but there are some other dodgy characters in the text. Allan Chapman himself appears as "Allanus Salfordiensis" and his wife Rachel (who supplied many of the sketches) is "Prioress Rachaela Eruditissima" of the House of the Consecrated Virgins of Norwich. Allan informs me that he has "used" some of his relatives for other persons who float in and out of the scene although it is not clear if the privy cleaner "Brother Daniel Cloacinus" is one of these, or idle "Simon Stultus" another. I'm not sure which one identifies Patrick Moore.

It is quite a small book but very attractive in layout, especially the cover. It is printed on yellow paper, presumably to simulate "age", full of illustrations and is entirely in Gothic script which some may find rather tiring to read although it gives me no problem. Just read it in small doses - and enjoy it.

Dave Gavine.


Scottish Astronomers' Group Meeting

The next meeting of the SAG will take place at the City Observatory on Saturday 20th May. Doors will open at 1pm and the meeting will kick off at 1:30pm.

In addition to the usual reports from Societies, Neil Grubb will be speaking about CCD Imaging. We hope to have another speaker as well and any update will be posted on the ASE website.

All members of the ASE are welcome to attend.

Scottish Astronomy Weekend 2000

The 14th Scottish Astronomy Weekend will be hosted by the Astronomical Society of Glasgow, on September 15-17. All activities, and accommodation, will be at the splendid Kelvin Conference Centre at Maryhill, near the Glasgow University Observatory. The main speaker will be the ever-popular Dr Allan Chapman of Wadham College, Oxford, whose theme will be "The Victorian Grand Amateur Astronomers". An interesting and varied programme is promised.

Our Edinburgh Society has always been a major supporter of the Weekends, so hopefully we'll have another good contingent. But please note that Dave Gavine is not the Organiser of this one. For information and booking arrangements please contact

Mr Robert Hughes,
Flat 1/2,
986 Crow Road,
GLASGOW G13 1JN.
Telephone: 0141 581 4322

 


Dorothy Mackie Spots the Shuttle Over Edinburgh

Friday 11 February 2000: The weather man at lunch time had said that if you looked west at about 5.50 pm you might see the Shuttle. Alastair, my son (who might still be ASE's youngest member) and I were at Harry Ramsdens, Newhaven harbour. I had parked facing west. A bright light came towards us from the direction of the Forth Bridges and passed overhead. It was very high, moving fast and too big for an aircraft or satellite. This might have been Endeavour accompanied by its large external tank (orange in colour). It was surrounded by a cloud of vapour or fuel. It was launched from Florida just 20 minutes earlier. According to the NASA web site target launch time was 1230 Eastern Standard Time and actual launch time was 1243 EST.

To make certain this was the Shuttle we had seen, the man to ask was Russell Eberst who has made hundreds of thousands of observations (this puts some of us in the shade, doesn't it!). He confirmed it to be the Endeavour as he also had seen it. Russell said 'In fact, Scotland is the first piece of land that the Shuttle passes over, when on a 57 degree inclination mission as this one was'. Endeavour was on the Radar Topography mission, to map the world. The mission would produce topographic maps of Earth 30 times as precise as the best global maps in use today. The benefits of the information gathered include ground collision avoidance systems for aircraft, better civil engineering, more precise land-use planning, better co-ordinated disaster recovery efforts, and communications improvements for cell phones.

Dorothy Mackie

[Editor: I wonder how many UFO sightings it set off! - Graham Rule has reported two phone calls to the observatory to report UFOs over Corstorphine Hill!]

Professor Hermann Brück

Recently members were saddened to hear of the death at the age of 94 of Prof. Hermann Alexander Brück, CBE, GCSG, DPhil, PhD, Hon DSc, FRAS, FRSE, Hon FRSSA, MRIA

His father was a Prussian Officer who died in 1914 when Hermann was still a young boy. He had his early education at the prestigious Kaiserin Augusta Gymnasium in Charlottenburgh which gave him a sound grounding in the Classics.

His university education was at the Universities of Bonn, Keil, and later Munich where he gained his DPhil in theoretical physics in 1928. He was invited to participate in the Potsdam Astrophysical Observatory physics seminars alongside the Nobel prizewinners Max von Laue, Erwin Schrödinger and Albert Einstein.

The growing power of the Nazis led to him moving to Italy in 1936 where he was received into the Roman Catholic Church. He worked for a year at the Vatican Observatory before joining Cambridge University Observatory under Sir Arthur Eddington.

In 1947 he was invited by Mr de Valera, the Taoiseach, to become director of the Dunsink Observatory in Eire and a senior professor at the Dublin Institute of Advanced Studies. His old friend Erwin Schrödinger was Professor of Theoretical Physics at the institute and Prof. Brück spend a happy 10 years there.

De Valera hoped to see the rejuvination of the observatory, which had fallen into disuse and Prof. Brück obliged and established close collaboration with the Armagh Observatory. Brück established the Boyden Observatory in South Africa and later handed it over to the joint management of the two Irish observatories.

In 1957, at the instigation of Sir Edward Appleton (another Nobel laureate and Principal of the University), Prof. Brück came to Edinburgh University as Regius Professor of Astronomy and Astronomer Royal for Scotland.

When the Royal Observatory was at the Calton Hill the Astronomer Royal had three assistants but there had hardly been any growth after the move to the Blackford Hill. When Brück arrived the full complement of staff was only eight but he set about transforming the Observatory and his University department into world leaders.

A century earlier, Charles Piazzi Smyth had suggested that observatories should be placed on mountain tops rather in cities. Prof. Brück encouraged the development of instrumentation to extend the usefulness of such observatories. Measurement of photographic plates was automated and the range of wavelengths detected widened. When he retired in 1975, the ROE had over 100 staff and was on the firm footing that has led to the establishment at the Blackford Hill of the UK Astronomy Technology Center.

In retirement Prof. Brück was not idle. Along with his wife, Dr Mary Brück, he enjoyed studying the history of astronomy. In 1983 he produced "The Story of Astronomy in Edinburgh" and followed this in 1988 with "The Peripatetic Astronomer" (co-authored with Dr Brück).

Prof. Brück had become a Member of the Pontifcal Academy of Sciences in 1955 and served as a member of its Council well into his retirement. When he became too frail to journey to Rome for meetings representatives visited him in Penicuik to get his views. On his 90th birthday he received an honour to rival the Royal Warrant appointing him Astronomer Royal for Scotland. Pope John Paul conferred on him the Knight Grand Cross of the Order of St Gregory.

Our Society has always invited the Astronomer Royal for Scotland to be our Honorary President and Prof. Brück served in this capacity during his time at the Blackford Hill and later became an Honorary Member.

We extend our condolences to Dr Mary Brück who devoted herself to caring for "the Professor" when he was in declining health.

 

On a personal note I would like to record my own appreciation of Prof. Brück. He was my head of department in my first job on leaving school and was always very encouraging.

I remember using one of the telescopes at the Blackford Hill with the University AstroSoc and having to keep the noise down in order to avoid disturbing the Brücks - he was the last incumbent to live in the official residence at the Observatory.

In an interview in a newspaper a few years ago I was fascinated to read of a run-in that the Professor had with Hitler when still in Germany.

I knew of Prof. Brück's connection with the Church but had not realised the esteem in which he was held. His requiem mass was celebrated by Archbishop O'Brien who read a personal message from the Pope. Astronomy has lost a great character who I wish I had known better.

The Society was represented at the funeral by Alan Ellis and myself.

Graham Rule


Mr J I Dodds & Mr J D Weir

Since the last edition of the Journal the Society has also heard of the deaths of two other members, Mr J I Dodds & Mr J D Weir.

Mr Dodds was a member of our Council in the 1970s and Vice President in 1981. He first visited the Observatory before the Society took over running it in 1938 - to be tested on star recognition for a Scout badge.

As far as I know, Mr Weir never held office in the Society but was a long-standing member. He had a great interest in "archeo-astronomy" and wrote "The Venus Tablets of Ammizaduga" (1972) and "The Venus Tablets : A Fresh Approach" (1982) discussing the (17th Century BC?) records of Babylonian astronomers.

We extend our sympathy to their families.

Graham Rule


Crossword

We haven't had a Journal crossword for a while (nearly 20 years!) Try this one. The clues are mostly astronomical, but not all. Sorry, no prizes such as a week's luxury holiday in Bonnybridge, and the answers will be in the next issue (or from the Editor if you are really desperate.)

Across

crossword table

1. 'When beggars die there are no ..... seen' (Julius Caesar). 2. The bright bits of Saturn's rings which stick out like handles. 8. German orbiting X-ray observatory. 9. He was boss on the Enterprise. 10. Constituent of comet's blue tail. 11. Dutchman's moon. 12. Earth science co-operation over 1957-58. 14. Moved to Sussex, then Cambridge, then closed down. 15. Extensive land-mass on a planet. 16. (& 19 Down) End product of enormous stellar demise. 18. (& 25 Down) There's a cat and a computer called Holly. 20. Silicate mineral in meteorites and deep Earth rocks. 22. St Lawrence weeps in August. 23. A proponent of the Steady State Theory. 27. Not old. 28. Our beloved Society. 30. See 26 Down. 31. Bradley's Aberration star.

Down

1. Essential part of Schmidt optical system. 2. He was looking for comets but made a different list. 3. Fairy moon of the Herschel planet. 4. Near-earth asteroid, one of a family. 5. Early research rocket. 6. E.g. 21st March. 7. They say lots of UFOs appear here. 13. Watch R CrB in case of a sudden 17. A refractor needs this. 19. See 16 Across. 20. The East. 21. Namely a crude 'adult' comic. 24. A start or an attack. 25. See 18 Across. 26. (& 29 Across) Our lately abdicated Leader but he's still around. 29. Piping around Saturn?

Dave Gavine

 

ADVERTISMENT

Are you looking for the perfect present? Something that will outlast even diamonds?

Why not
NAME A STAR

Whether it is for that special person in your life or as a lasting memorial to a dear one now departed you can name a star for them.

For only a few hundred pounds we will register the name of your choice in the records of Edinburgh's Calton Hill Observatory. This observatory has been a centre for astronomy since the 18th Century and was granted the title of 'The Royal Observatory of His Majesty, King George IV' in 1822.

Just send us the name of the constellation from which you want our astronomers to select a star, together with a cheque for £200, and within days you will receive a certified extract from our records and a Star Chart showing where your star may be seen in the sky. [1]

For our deluxe service, costing only £50 extra, you can pick anywhere in the world and we will send a listing of the rise and set times of your star. [2]

For added security, your choice of name and the details of registration will be recorded with the National Library of Scotland and with the British Library. Please ask for details of our special arrangements to include registration with the US Library of Congress. [3]

So what are you waiting for? Contact us now and NAME YOUR STAR.


Acceptance subject to status. In the event of your star becoming faulty within 100 years of registration we will replace it free of charge with one of equal or greater value.

1) A 12" telescope may be required in order to see your star - a list of suppliers of these will be included if requested in advance.

2) For geometric reasons this service is not available for the North or South poles and may limit your choice of constellations.

3) Registration with government authorities is updated every 6 months so there may be some delay before you can see the name of your choice in these libraries.

 

 

Have you ever been tempted by an advertisment like this? Or do you know someone who has? Recently the Society has been contacted by a number of people who wanted to 'name a star' and I've noticed a number of web searches going on for organisations that sell this service.

While our advert is not meant to be taken seriously, as far as I can tell, there would be nothing illegal in placing it in a newspaper and running our own star naming service.

 

The information about the observatory is factually correct - if a little incomplete in that it doesn't mention that the Royal Observatory moved out a little over 100 years ago. There is no technical difficulty in producing a list of stars and assigning names to them. After all, naming stars has been going on for thousands of years.

We could provide charts showing the stars - either from a computer planetarium program or (if someone is paying a lot we can afford to be generous) with charts cut out of a copy of Norton's Star Atlas.

I suppose that we wouldn't 'register' the star names until the cheques had cleared.

Since all publications have to be sent to the Copyright Libraries all we need to do is publish our 'register' (as a seriously limited edition book or as a supplement to our Journal) every six months. (Our Journal is in the National Library in Causewayside.) Not that anyone is likely to notice the names we register. The holding of a publication in these libraries doesn't imply any endorsement of the content by these official bodies. Similar regulations apply in the USA with the Library of Congress so we would probably need to 'publish' something over there to get it into that library.

So, given that there is no Government endorsement of the entries on our register, does that mean that only astronomers would use the names so carefully paid for by our customers? No, not even that will happen. Names of celestial bodies are assigned by the International Astronomical Union according to strict rules. They do not 'sell' names. And the names they assign are only used on this one tiny little planet - what about all the Interplanetary Astronomical Unions scattered around the cosmos?

The names in our register are meaningless. Why would anyone pay for them?

Now it might be that our customers would be happy to pay quite a lot for a certificate and a star chart (more if they want to know when 'their' star rises and sets). And, if the price was low enough, this isn't a bad 'novelty' idea. As long as the customer knows that this is all it is.

There is an IAU note about naming stars on the web at http://www.iau.org/starnames.html which states that ... the IAU dissociates itself entirely from the commercial practice of "selling" fictitious names of stars.

The Royal Astronomical Society issued a press release when, in 1996, John Major 'named' a star in memory of the victims of the Dunblane massacre.

If you hear of someone wanting to 'name a star', why not encourage them to learn more about all the stars. Even if they can't buy one for their exclusive use they can learn how stars work, how the appearance of the night sky changes throughout the year, what the planets are like, and get a whole new perspective on the universe.

If they come up to the Observatory on a clear Friday night we can let them see real stars and planets when they are visible. If they are not from the Edinburgh Area get them to contact their local Astronomical Society (see the lists in the Federation of Astronomical Societies handbook. Suggest that they lend their support to their local society or perhaps to the Campaign for Dark Skies so that the stars can be seen at night.

There is so much more they could do with their money than give it to an organisation that will 'name a star' for them.

Overall I think I've talked myself out of setting up a Star Registry. So what else can I try? I know...


 

Ever wanted to have a large bridge between Edinburgh and Fife named after you?
Choose between road or rail bridges and send your cheque to ....

Graham Rule

Observing Variable Stars

The observation of Variable Stars is one branch of amateur astronomy in which the participant can make a serious contribution to science. Although a small percentage of amateurs are armed with higher orders of technology incorporating photometers and other gadgets any observer owning a pair of binoculars or small telescope can find a programme of work suitable to his or her circumstances.

Many stars vary in brightness cyclically or irregularly due to internal instabilities or to the effects of one member of a binary pair of stars either eclipsing the other or by exchanges of matter between the two. Observations by amateurs of these variations are of value to professional astronomers in their theoretical studies of stellar constitutions. The professional observer has little time to monitor stars continually while his observatories are usually booked for years ahead on short-term specific study programmes. The amateur can act as lookout and warn the professional of unusual occurrences that demand his immediate attention.

The British Astronomical Association (BAA), the American Association of Variable Star Observers (AAVSO), the Webb Society, The Astronomer (TA) and the Society for Popular Astronomy (SPA) all involve amateurs and the first two issue charts of the sky surrounding each variable that they wish to have studied. Each chart depicts the stars in the immediate neighbourhood of the variable giving the magnitudes of certain stars calibrated usually by a professional observatory and not thought to be variable themselves.

The amateur observer estimates which companion star is immediately brighter than the variable, and a second star immediately fainter than it. The observer then estimates the difference in brightness between the variable and its companion stars. This is known as the Fractional method, as follows

Let the variable star W Cygni lie in brightness between comparison stars F (mag 5.54) and A (6.12) so that it appears to be 1 "step" down from F and 2 "steps" up from A:

observation: F(1) V (2)A No. of steps = 3
6.12 - 5.54 = 0.58
0.58 / 3 = 0.19

Therefore estimated mag. of variable = 5.54 + 0.19 = 5.73, or approx 5.7. (remember that the fainter the star the larger the magnitude number.)

The experienced observer can train the eye to detect differences in brightness in terms of tenths of a magnitude and make estimates of the variable brighter or fainter than a single comparison star. This is known as the Pogson method and can be useful in certain circumstances.

Dave Gavine, Lorna McCalman and myself are presently engaged in programmes of variable star observing. Dave uses 7 x 50 and 11 x 80 binoculars, Lorna employs 15 x 80 binoculars and I observe with a 65 mm Russian-made Alcor reflecting telescope on an altazimuth mounting. The team are generally observing the same stars with variations in individual programmes. My own list is UU Aur; V377, V465, TU & WX Cas; CH, SS & W Cyg; U & EU Del; R Gem; V566 Her; BQ Ori; S & X Per; BU Tau.

Ron Livesey

Dave Gavine adds: There are a number of good variable stars for the beginner. Most of them are of the type SR (semi-regular) which vary over weeks or months by a magnitude or two but tend to do unexpected things like varying in period or amplitude so their observations are useful. Browse the Internet, especially the BAA pages (home page http://www.ast.cam.ac.uk/baa ) which will get you onto subsequent Variable Star Section pages. Here you can find lists of stars with their identification charts and recent light-curves. Ron, Lorna and I "discovered" all this recently and it's a goldmine of information. Examples of these stars are shown. I chose these because four of them are nearly circumpolar - you can observe them nearly all year. U Monocerotis, however, is a striking variable of shorter period - a few weeks, is easy to spot and is surrounded by easy guide stars with which to compare it. Unfortunately it is low in the southern sky and is with us only in winter and early spring. For these stars it is best to use binoculars - big ones, of at least 10 X 50, and observe every few days. Sometimes there will be gaps in your programme, during a bright moonlit spell, bad weather or the midsummer twilight. Then plot your results as I have done, as a light curve, and you can compare it with the BAA or TA results. Those BAA members who gain confidence may then like to join their VS team and contribute regular observations.

Star chart for variable star AF Cyg

E 6.3
G 6.8
J 7.1
L 7.2
N 7.5
Q 7.6
R 8.2
S 8.4


Star chart for variable star V465 Cas

P 5.7
C 6.3
A 6.6
P 7.0
B 7.4

 

Some light curves of variables