Constellation of the Month - Virgo

Peter Oglivie

Virgo is the second largest constellation in the sky and as one of the zodiac constellations it is the home of the sun from late September to late October, including the equinox on Sept. 23rd, when the sun crosses the celestial equator from north to south. In May however, Virgo is well placed for observing in the evening.

Being well outside the plane of the Milky Way, Virgo contains no open clusters and no nebulae, either diffuse or planetary. There is one distant globular cluster and a few double stars. The primary interest in Virgo is galaxies. There are in fact hundreds of them, because this is the location of the enormous Virgo-Coma cluster of galaxies centred about 60-odd million light years in distance. All my observations were made with a 10-inch telescope on a clear dark night. We'll begin with some stars.

Alpha Virginis (Spica) is a giant blue-white star of spectral class B2, apparent magnitude is 1.2 at 260 light yrs distance. It is also a spectroscopic binary with a period of 4 days.

Gamma (RA 12h 41.7m, Dec -1 deg 27m) at mag. 2.9 is a bright double star. Both components are virtually identical white FO stars each of mag. 3.6 with a period of 172 years. Maximum separation in 1922 was 6 arcseconds and we are approaching a 2005 minimum of only 0.25 arcseconds. The current separation is 1.9 arcseconds. I could still split them at a power of 100X or more. They will be an interesting pair to watch annually as they approach minimum.

Theta (RA 13h 9.9m, Dec -5deg 32 m) An easy binary of magnitudes 4.4 and 9 separated by 7.2 arcseconds, white in colour.

Phi (RA 14h 28.2m, Dec -2deg 13m) A white and orange binary of magnitudes 5 and 10 with a separation of 4.5 seconds.

31 Vir (RA 12h 42.0m, Dec +6deg 48m) Binary, mag. 5.5 with a faint 11.6 companion at 4 seconds.

84 Vir (RA 13h 43.1m, Dec +3deg 32m) Binary, mags 5.6 and 8.2 at 3.2 seconds. Colours are orange and yellow-white.

54 Vir (RA 13h 13.4m, Dec -18deg 50m) Binary, mags 6.3 and 7.3 at 5 seconds, both white.

Situated half-way between mu and iota Virginis is the distant globular cluster NGC 5634 (RA 14h 29.6m, Dec -5deg 59m) estimated to be about 75,000 light yrs away making it comparatively small and dim for a globular, around mag. 10. It is not too hard find but requires a moderately large aperture to resolve any stars.

Now for the galaxies. There are so many visible in a telescope of 10 inches, one becomes lost quite easily. The difficulty lies in being able to identify which one you have in your field of view. It certainly helps if you start with one of the brighter Messier objects near the heart of the galaxy cluster then move around in a measured, methodical manner. I will concentrate mainly on the brighter ones.

Start with the pair of big elliptical galaxies M84 and M86 at the heart of the cluster half-way between the bright stars Beta Leonis (Denebola) and Eta Virginis (Vindemiatrix). The galaxies appear as two very conspicuous ovals within the same view. With a 'scope of 8 inches or more you might also see the fainter, elongated NGC 4388 forming a triangle with the other two. With 10 inches under a dark sky you might even spot the quite faint NGC 4387 sitting neatly in the centre of the triangle. From here, move about 1/2 a degree east to see the close pair 4435 and 4438, the latter distinctly elongated. A photograph and a map of this region appears on the cover of the Herald-Bobroff Astroatlas, showing 4438 to be quite distorted.

Now moving about 1 degree SE we find the massive elliptical M87, quite bright and a little larger than M84/86. Short exposure images at high magnification show a powerful jet shooting from the nucleus, while long exposure, wider-angle images reveal the M87 to be surrounded by a swarm of hundreds and hundreds of globular clusters. Just over 1 deg. E of M87 we find M89 which has a tiny, almost stellar nucleus. Moving 2/3 deg. N and 1/3 E is M90, also showing a tiny nucleus.

From M90 move 1 1/3 deg. S to find M58 next to an 8th magnitude star, then about 1 degree E to M59. Just a nudge further E you will see M60, in the same wide-angle view with M59.

If you're not already lost, then from M59/60 we swing 3 1/2 deg. S, then 3 1/2 deg. W to locate the massive elliptical M49, bright but a little harder to find as it is more isolated. Superimposed on M49 is a star just east of the core. You haven't discovered a supernova. It's just a foreground star. About 1 deg. E from here we find the conspicuous NGC 4526 sitting snuggly between two 7th mag. stars, then 1/2 deg. N to find 4535, a little larger and dimmer.

Moving now about 5 deg. SW to find M61, first locate the 5th mag. star 16 Virginis, and M61 is 1 1/2 deg. NE of that. That almost covers the Messier objects, but I've saved the best until last. Without doubt the showpiece galaxy in Virgo has to be the nearly edge-on spiral M104 (the Sombrero) on the Corvus-Virgo border (RA 12h 40.0m, Dec -11 deg. 37m), 5 deg. N of Eta Corvi then 2 deg. E. Close to a tiny line of 3 faint 9th mag stars, M104 has a relatively high surface brightness for a galaxy due to its orientation combined with a large nucleus. In telescopes of 8 inches or more you can see its dark dust lane along the length of the disk.

From here you could go on and on, as there are many more galaxies within range of moderate apertures. Virgo is a galaxy hunter's paradise.

Resolving Unequal Double Stars

Ross Gould

There are many double stars in the sky, wider than the resolution limit of a telescope, which it has no chance of resolving. The reason is that the stars are faint, or of uneven brightness. The Dawes Limit, commonly quoted, applies only to equally bright stars of about magnitude 6. For uneven pairs, or fainter ones, the numbers change. Most double stars are uneven in brightness, and there are far more faint pairs than bright ones.

Both R.G. Aitken and H.D. Lewis looked at this matter earlier in our century. Aitken's study was based on results from three observers all with the 36-inch Lick refractor - so it has little practical application for amateur observers, because there are too many factors that differ between large and moderate apertures. Most amateurs have telescopes with far less light gathering and potential resolution than the Lick telescope.

More useful was a 1914 study by T. Lewis which looked at a large number of observers with a variety of telescopes, from 4-inch to 36-inch aperture. Lewis's results show a good deal of scatter from one observer to another - but he came up with a set of averages. These are as follows:

• Equal bright pairs (mean mags 5.7 and 6.4) 4.8/a
• Equal faint pairs (8.5 and 9.1) 8.5/a
• Unequal pairs (6.2 and 9.5) 16.5/a
• Very unequal pairs (4.7 and 10.4) 36.0/a

Lewis's figures may be taken as a "safe" estimate of what a good telescope might achieve under steady seeing conditions. Because Lewis's figures are averages, one might expect it would sometimes be possible to better them .

This and other matters were taken up by P.J. Treanor in 1946. Treanor graphed Lewis's results for each observer, and compared these with what diffraction theory might suggest. Of interest is that some of Lewis's observers did achieve or approach the theoretical prediction, thereby exceeding considerably Lewis's averages.

Several factors come into play here. First, one assumes all telescopes to be of high quality - in this regard, it is well for the modern observer to remember that high quality optics are not a recent invention. Second, published measures do not always reflect the limit of what a telescope can do - published measures are subject to selection effects on which pairs are measured.

The Observer

One factor here is the quality of eyesight, which we know varies. More significant is how well the observer can "see through" the flicker and wobble of star images at high magnification. It was said of RTA Innes, one of the notable double star observers, that he could measure a pair which David Gill, one of the great observers, could not even see. William Rutter Dawes was known as the"eagle-eyed" because of his remarkable ability to see obscure details at the telescope. In everyday life he was very short-sighted, but this can be an advantage for telescopic viewing, increasing the effective magnification. Sharpness of sight, combined with an ability to integrate the fleeting moments of clear vision or the fragments of that, make a difference.

Finally, practice helps. My recent experience is of seeing pairs more readily now than I did several years ago, because I have observed so many, some of them difficult or very difficult. Difficult pairs require Hartung's "close attention", and this takes practice. Practice can be conceived of by a musical analogy, as the playing of whole works, rather than going through scales - it becomes a pleasure and gives a sense of achievement.

Surpassing Lewis?

To return to Treanor. Although he rightly points out that Lewis's averages have been improved on by a number of observers, he also suggests that the theoretical limit is unlikely to be achieved for uneven and faint pairs.

I have therefore re-examined Lewis's table of observers, and tabulated individual results from all of these, expressed as Treanor does in multiples of the Dawes limit - for each observer and each type of pair. I have restricted myself to telescopes in the 15-cm to 36-cm range, both because this reflects typical amateur telescope sizes, and because large telescopes are commonly less efficient due to seeing and other factors.

Regarding this - the doubles found and measured by SW Burnham, the famous American double star observer, show the effect of changing aperture. As Louis Bell in The Telescope (1922) puts it, discussing Burnham's discoveries with telescopes of "6, 9.4, 12, 18.5 and 36 inches" - "With the 6-inch aperture Burnham reached in the average 0.53 of Dawes' limit... and he also fell well inside Dawes' limit with the 9.4-inch instrument. With none of the others did he reach it and in fact fell short of it by 15 to 60%. All observations being by the same notably skilled observer and representing discoveries of doubles, so that no aid could have been gained by familiarity, the issue becomes exceedingly plain that size with all its advantages in resolving power brings serious countervailing limitations due to atmosphere."

Recent Observing

Larger telescopes certainly have the advantage in light gathering, and this helps with faint companions. My experience on some doubles viewed with both a 14-inch Celestron and a 7-inch refractor show the benefit of increased light grasp, though in uncertain seeing conditions the greater sensitivity of the larger aperture to the atmosphere reduces the benefit. Even so, four times the light is obvious at the eyepiece.

A good larger instrument in good seeing may show pairs beyond smaller apertures - with the C14 I have for example split:

• Fin 205 Cen: m5.0, 10.3: 2.7" - just split 120x, held steadily at 240x, "difficult but definite".
• HdO 255 Aps: m6.7, 10.7: 2.2" - companion just visible 160x, perhaps better 240x: difficult.
• Rst 2943 Aps: m7.6, 7.9: 0.5" 102 1990 PA dec: just double at 430x.
• I 487 Pup: m6.5, 10.0 - 1.9" 023 1983 relfix
• I 424 Cen: m4.8, 8.4: 1.9" 007 1980 slow PA, dist inc.
• I 147 Eri: m7.5, 10.3: 1.3" 338 1943 relfix - difficult, 240x.

This is close to Lewis's limit, about 1.15" for 14-inch aperture. The seeing that night was middling, not excellent. These show something of the benefits of aperture.

Notice that the near even pair was split at 0.5"; with 2.8 mags difference 1.3" is difficult; with 3.5 magnitudes difference, 1.9" is moderately difficult; at 4 magnitudes, 2.2"; and at 5.3 magnitudes, 2.7" is possible and not a severe test. Lewis's figure for 5 mag difference would give 2.6" as a limit for 14-inch aperture - given the view of Fin 205, I would expect the limit to be closer to 2.0" for 14-inch aperture. Yet this is the most difficult of the pairs in terms of Lewis's parameters.

Based on a selection of observers I have come up with a new set of parameters indicating the likely limits of performance. These parameters are less testing than those based on diffraction theory (Treanor's limit). However to achieve this level of performance requires excellent optics, an experienced eye, and very good seeing. Lewis's figures are closer to what might be readily achieved in good conditions.

Treanor Limits

Based on diffraction theory, if we state separations in DL units (Dawes Limit), then for a given aperture separations for delta-m (magnitude difference) are:

• 1m 1.2 DL
• 2m 1.5 DL
• 3m 1.8 DL
• 4.4m 2.3 DL
• 5.9m 3.24 DL

My preliminary suggested practical-possible limits are:

1. Bright equal stars m6+6 = 1.0 DL
2. Fainter equal stars m8.5+9.0 = 1.8 DL (effectively the same as Lewis)
3. Unequal pairs m6+9 (dm=3) = 2.5 DL (Lewis = 3.5 DL)
4. Very unequal m5+10 (dm=5) = 5 DL (Lewis = 7.9 DL)

I would add another line: for unequal fainter pairs

5. Unequal fainter m8+11 (dm=3) = 2.5 DL (same as brighter unequal pairs).

Because there is less glare effect from a fainter primary star, the fainter secondary remains equally visible in terms of separation. With the 18cm refractor, where the figure for dm=3 is 1.63" arc (2.5 DL), some pairs I have split include:

• I 494 Car 7.5, 10.1 (dm=2.6) 1.9" difficult, 180x
• Slr 16 Vol 7.4, 9.5 (dm=2.1) 1.0" 330x v.difficult
• I 192 Vol 7.5, 10.3 (dm=2.8) 2.0" only moderately difficult, 100x
• Mu Vel 2.9, 6.6 (dm=3.7) 2.1" (1995) - v. difficult at 180x and 330x

Mu Velorum incidentally was discovered by Russell in 1880 at 2.8" and PA 055 - despite a calculated orbit of 116 years, in 1995 the measure was 2.1" at 051, suggesting the period is somewhat longer than that.

I still have some way to go on all this - first a study of all the more difficult pairs I have seen with various telescopes under good conditions; second, looking at the most difficult pairs found at Sydney by Russell's group, with 7.25 and 11.4 inch apertures, and those found by Innes with 18-inches - these are not part of Lewis's study.

Far Away and Long Ago

Ross Gould

A little while ago I offered to write something on the NSW Astronomical Society in its earlier days; recently I was asked to write the next astro-autobiography in our club series. What follows is a combination of the two, with extras.

Beginnings

How to recall one's first interest in astronomy? - somehow it happened, and early memory tells that the sky was a matter of importance, though not why it was. I do know that by age 9 I was reading books on astronomy, and despite the lack of a telescope or even binoculars I watched the parade of celestial objects. My 11th birthday present was Norton's Star Atlas, plus a little book on identifying the southern star groups, by M.A. Orr. My family lived at the time in Lindfield, on Sydney's North Shore, and the bush started at the end of the yard - providing a dark sky. We moved soon after to Hurstville, in Sydney's south.

That year I came upon the Astronomical Society of NSW, in those days still called the Sydney Amateur Astronomers. It had been established about 1955, from some ex-members of the NSW BAA deciding to set up an alternative group. I became a member of the flourishing and populous junior section, which included quite a few girls despite this being pre-feminist days. As well there were adult members who visited to talk about astronomy. Junior meetings were held on Saturday afternoons, and sometimes extended into evening observing.

The Patston family's huge yard at Belfield in Sydney's inner west was the location for meetings, at first in a garage, then in the new clubhouse which the members constructed. Hot summer afternoons, and milder ones, in the garage or beside it, gave way to a more settled existence in the clubhouse. When it was completed, Bart and Priscilla Bok were invited to do the official opening, another highlight. Among junior section experiments was photographing star trails with a fixed camera, an enterprise now overshadowed by David Malin's superlative example. My fondest memory of this endeavour was the young woman in the chemist shop who asked, when I picked up my prints, whether one used a flash to photograph the stars.

Club Telescopes

At the back of the grounds a "moonwatch" fence of small telescopes had been erected, for observing the early artificial satellites of the space age - this survived until the early 1960's. When I joined the group there were regular satellite watching nights, a fence of observers sitting at their little "moonwatch" elbow telescopes. Satellite transits were timed - this allowed better orbit calculations, including knowledge of decaying orbits as low Earth satellites gradually surrendered to drag from the upper atmosphere.

Near the clubhouse was a 10-inch F/8 Newtonian telescope, in those days a considerable instrument. There was also a venerable 4-inch Cooke refractor, sans finder, which had its own pillar near the moonwatch scopes. This instrument had been part of the observatory of Ernst Wunderlich, of the family which had founded the Australian iron and steel industry. Because juniors were rarely allowed to use the club's 10-inch reflector, the 4-inch refractor got a considerable workout - and it convinced various of us that refractors had a special quality, with only a lack of aperture as a disadvantage.

I had already been smitten by the refractor bug because my first impressive views of the sky were at age 12 at Sydney Observatory, through the 11.4-inch refractor. Mars showed dark markings and a polar cap; and Saturn, with nicely open rings, was impressive - the Moon was amazing, and three-dimensional - great mountains and deep craters at 300x - it was the region of Theophilus, Cyrillus, Catherina, on the terminator that night.

The 4-inch didn't quite match this, but was impressive nevertheless. The lack of a finder meant one had to learn to starhop by sighting along the tube. No Telrads in those days to obscure the fainter stars with a red glow. And Sydney light pollution levels were less overwhelming then - the 4-inch showed stars in 47 Tuc, for example.

In the early 60's there was an attempt to build a “coelostat” (not a fossil fish) for solar observing. This included a tunnel under part of the grounds, along which the solar image would be projected. The coelostat was never finished, but was a fascinating diversion for a time.

During the 1960's the NSW Society received the "McNiven Gift", a 6-inch Unitron refractor on an observatory mount. McNiven was a wealthy ice-cream manufacturer who had bought the telescope from Esdaile's (the source for telescopes in Sydney then) to look at yachts in the harbour. EW Esdaile, the firm's founder, proposed instead that McNiven donate it for astronomical use. The telescope was donated and not long after someone broke into the clubhouse and stole the optics.

EW Esdaile meanwhile was feted in the Society, and was talked into writing a reminiscence of the Goondiwindi eclipse expedition in the 1920's. I later found that Esdaile had been part of the NSW BAA at least as far back as 1906, and therefore had begun in the latter end of Tebbutt's era. But there was a great silence in the 60's at Belfield on matters of history - despite Peter Williamson recalling visits to the Tebbutt Observatory (with another society).

Bok and Eggen

Apart from junior meetings, one could go to senior gatherings - and there encounter among others the impressive figure of Bart Bok on those occasions when he was able to visit from far away Canberra, to seduce all listeners with his enthusiasm and larger than life personality. I first came across Bok through his and Priscilla Bok's book The Milky Way - shortly before I encountered the authors in person when they visited Belfield. In those days one also saw Bok on television - he was advocating a large telescope for Australia, at first a 120-inch - an advocacy which led eventually to the AAT at Siding Spring, by then enlarged, as seemed to happen with most things Bart Bok put his enthusiasm behind.

The last time I saw Bok in person was at a very crowded public lecture in Sydney, given at the old Sydney Tech College in Ultimo. He spoke on the Magellanic Clouds. We regretted his departure a little later. His successor was to prove very different - we had all been lulled into a sense of positive relations by Bok - and a feeling that amateurs had a place in the world, could collaborate with professionals. Astronomy was for everyone - and could exist in different forms.

The coming of Olin Eggen as Bok's successor at Stromlo provided "the shock of the new"... it was as if Bok's qualities had been systematically reversed. Eggen spoke against the "ooh, ah! school of astronomy", which seemed to be his description of amateurs. His manner was neither welcoming nor inspiring. Eggen essentially wiped out the previous style, without there being anything to replace it - consequently he became irrelevant to amateur astronomy. Other professionals were cultivated instead, though with a lasting sense of disappointment at the gap created. After Bok, disappointment was inevitable - Eggen's style exaggerated the change.

Getting a Telescope

We juniors were, however, encouraged into telescope making. These were the days of do-it-yourself if you wanted an affordable telescope of reasonable size. Mirror making kits with 5-inch diameter glass were made available. I recall long hours grinding my way through increasingly fine powders in hope of a mirror at the end. I still have the disks, unfinished. At that time I had only an old brass and leather marine telescope, passed on to me after an elderly uncle died when I was fourteen. This hand-held, 40 millimeter aperture beast at least showed what any good finder will - Jupiter's moons, larger lunar craters, some star clusters... anything helped.

I finally solved the desire for a "real telescope" at age 16, when one of the older members died, and his widow put up for sale his two telescopes, a 3-inch refractor and 6-inch reflector. She wanted them to go to "good homes". I bought the 6-inch reflector, with some parental help, and I retain an affectionate feeling for Arthur Thomas, whom I had not known, for the telescope I "inherited" from him. My friend John Gilbert bought the 3-inch refractor. Soon after another of the juniors came by a 5-inch refractor. This had been found under a house in Vaucluse! Yet another with family help acquired a 10-inch F/12 Newtonian - this monster proved difficult to set up and to use. Other junior members had previously resorted to 6-cm refractors, mostly unsatisfactory.

The mounting of my telescope was an equatorial head with setting circles, mounted on a steel pipe loaded with concrete. This my father and I dug up from its previous location, and re-erected in the backyard at Hurstville. A bag over the mounting kept it weatherproof - observing only required carrying outside the tube assembly, no great weight. The mounting was permanently aligned. Despite no drive, it was a useful arrangement.

This telescope stayed with me for quite a few years, and showed many objects in addition to the usual showpieces. Among the highlights of its use was finding a comet, which I hadn't known was about - of course it had been discovered some time before, but I briefly had the experience of independent discovery, as for some reason notice of the comet's reappearance from around the sun had been overlooked in the society. The finding was fortuitous - I've never had the patience to go comet-hunting, and I'm still happy to leave that activity to Vello and Bill Bradfield.

A Comet, Flare Stars and People

The comet served as an introduction to Arthur Hogg, Deputy Director at Mount Stromlo under Bok, who happened to be the guest speaker that month at the SAA. He was positive and encouraging about finding ways into astronomy. Dr Hogg died only a few years later, as acting Director just after Bok's departure from Stromlo.

The 1960's at Belfield were a period of planetary observing and flare stars - planets were in vogue in those pre-Neil Armstrong days, and the new flavour was the flare star program done with CSIRO. Amateurs watched red dwarf stars for long hours at the eyepiece, in the hope of seeing a flare - while radio telescopes "listened" to the same objects. It was an attempt to open two windows simultaneously on the same objects, to correlate radio and optical observations. It also gave some of us our first view of Proxima Centauri, one of the flare stars.

I recall editing a junior section journal for a period, and showing the sky at a variety of "field nights", what we'd now call public nights. In the late sixties I usually operated the 4-inch Cooke. The first field night I went to was held off-site, in Parramatta Park, not far from the remains of Governor Brisbane's Observatory of the 1820's (some masonry pillars). This was long before Parramatta became the geographic centre of Sydney, and gained an overlit football stadium. The experience lingers, including a view of Omega Centauri in a "superfinder" - a 5-inch F/5 someone had constructed around the objective. People came, and the sky was reasonably dark despite half Moon and local lights.

I have said little thus far of club personalities. Gordon Patston was one of the prime movers and shakers in the NSW society of those days, the single most significant person. There are times I feel he was like the larger than life 19th century astronomers, and he certainly brooked opposition as little as Henry Russell had done. He was capable, determined, a good observer, a telescope maker, and one of the "true believers" in astronomy. He also believed strongly in the good work done in the junior section, despite a falling out between him and our first section leader, Laurie Shannon, leading to Laurie's departure. A loss. Laurie's replacement was a young science teacher, who left after a time to take a job with the rather new Parkes Radio-telescope.

End of an Era

In 1969 the Great Schism occurred, and the NSW Society lost its clubhouse and site. There had been an attempt to change the nature of the society, and this was resisted by some members. Personalities had too often loomed overlarge in that group - in 1969 this came to a head, and the society split and became homeless. Not being inclined to politics or fighting, I ceased to be a member.

I joined the Sutherland Astronomical Society, at that time named after Captain James Cook. Then as now it was a friendly group, with an absence of the personality conflicts and politicking that had periodically disturbed the NSW group, even before 1969. Here I found the Belfield 10-inch reflector again - it was lent there, as the NSW Society no longer had a site. Keith Selby, one of its makers at Belfield, was a founding member of Sutherland.

While a member of the Sutherland group I observed a series of mutual events of Jupiter's satellites in 1973. This I found fascinating, particularly the occultations, watching the satellites approach each other, blend and merge, then separate again. On steady nights a six-inch Newtonian allowed satellite disks to be seen, of varying size - though it was not able to show partial occultations as figure-8 shapes. A bigger telescope would have been useful, for better resolution. Even so, my timings were fairly good, and one correlated within a few seconds of a photoelectric series done at Siding Spring.

Who Did What When?

I had developed an interest in the history of astronomy at an early time - came 1972 and I decided to look more closely at Australian astronomical history, an area I knew little about, and on which I could discover few writings. The best of these was Pietro Barracchi's article, revised by Richard Woolley, in the old Australian Encyclopedia. I began to read through the old journals, and discovered a wealth of material lying fallow. In 1973, doing a Dip.Lib. course at NSW University following a degree at Sydney, I made my thesis component of the course an annotated bibliography of Australian astronomy - choosing the period 1820-1920 to keep it manageable.

I spent much of that year in the Public Library of NSW and its Mitchell collections, looking at both published and manuscript materials. Apart from discovering many "forgotten worthies" I was able to wander through papers annotated by John Tebbutt and others, and read some of the correspondence so prolific in pre-telephonic days.

In 1974 I spent two weeks at Sydney Observatory, to check old letterbooks and manuscripts, as well as some publications not available elsewhere. It was a fascinating experience - the thick stone walls of the Observatory eliminated the sounds of Sydney, and it was like stepping back a hundred years. I almost felt that turning a corner I might encounter the irascible Henry Russell, the late 19th century Government Astronomer who was at the observatory for over 40 years until his death in 1907. There were instruments from Governor Brisbane's Parramatta Observatory on display, rescued after that place became victim to white ants in 1848. Some later instruments, no longer in use, were also displayed.

This time gave me acquaintance with Harley Wood, who was to retire later that year. On social occasions - one occurring while I was there, a staff member departing - Harley would be encouraged to tell one of his stories. These dated back to "the old days" - pre-WWI, often 19th century. Harley had apparently got these from James Nangle, who was Government Astronomer when the young Harley came to the Observatory in the Depression years. Nangle went back a long way - born in 1868, he had been a stalwart in the NSW BAA, and was acquainted with Russell, Tebbutt and others of that earlier time.

On that day Harley's story was of Henry Russell. "When I came here in the 30's," he said, "there were still wires running from the Director's office throughout the Observatory, high on the interior stone walls. In Russell's day there had been a bell above each desk. When the Director wished to see someone, he would pull the wire and the bell would ring above the person summoned. One day, Russell wished to see one of his assistants. He rang the bell, but no-one appeared. He rang again, but still no assistant. Russell went looking for the man summoned, and found him at his desk. 'Did you not hear me ring, sir? Why did you not come?' To which the reply, 'I would not summon my dog that way'". The story is very revealing of Russell's character, and of Harley's choice in stories.

I came to think the unidentified assistant was CJ Merfield, a fine mathematician at Sydney Observatory who later moved to Melbourne Observatory. He and Russell got on badly - and I found while there a note from Russell complaining of Mr Merfield, who tried to sneak by under the Director's window when he arrived late for work, "but I saw him". Russell's note made plain this was only one of many faults he had found in Merfield.

The tales of that era are wonderful, but too many of them have been lost. Harley appears not to have recorded them before his death, soon after Sydney Observatory became a museum. The other person who knew them was Bill Robertson, his chief assistant and briefly Government Astronomer after Harley. Robertson died not many years after, as I discovered from his son-in-law who visited the Canberra Observatory while it was still at Dickson. Robertson had been at Sydney Observatory from the early 1940's.

I joined the NSW BAA, and went to some meetings, still held at the Observatory. In mid-1974 I was offered a job at ANU, and left Sydney.

Soon after arriving in Canberra I joined the CAS, which at that time had similarities to its form in more recent years, meeting at the Jaeger Building, and going on graze expeditions. But all that is another story.

It is a curiosity of time in one's memory, that although I have been a member of the CAS for about twice the period I was a member of the SAA/NSW Society, the shorter span of years, being in childhood and youth, seems more busy and eventful than the far longer time in Canberra. The plateau of adult life foreshortens perspective, while the endless days of youth stretch out to the horizon.