Last weekend, 28-29 April 2012, I attended the annual meeting of the Australasian Planetarium Society at Auckland Stardome Planetarium and Observatory in New Zealand. The agenda for the meeting included the showing of many exciting planetarium shows and two talks to which members of the Auckland Astronomical Society (AAS) were also invited. One was a talk by me on the forthcoming transit of Venus and the other was by Dr Grant Christie of Stardome and the president of the AAS on the detection of exoplanets, that is, planets around distant stars.
Here I report on Dr Christie’s fascinating talk that was held in the very comfortable surroundings of the planetarium dome. Of course, any errors in the report are my own and possibly due to those comfortable surroundings.
Astronomers, like almost everyone, else are curious to know if there is life elsewhere in the Universe. Judging by our own situation on Earth, good places to search are on planets around stars other than the Sun. The first step in this quest is to find those planets. Since the mid 1990s many exoplanets have been discovered, initially by looking for a small wobble in the motion of stars due to planets circling around them. More recently, the Kepler spacecraft has been finding numerous candidate planets with the transit method, which is looking for the slight dimming due to a planet moving in front of a star.
There is, however, a third method involving gravitational microlensing, which is particularly useful in finding planets in the Goldilocks or habitable zone, that is, at a distance from its parent star that is neither too hot or too cold for water to exist in liquid form. Liquid water is likely a necessity for life.
Any star can act like a lens increasing the brightness of another star that happens to pass behind it. Such events are, of course, so rare that calculations suggest that the probability of it happening for any star is one in a million. In spite of this low probability, astronomers are finding hundreds of such events a year by monitoring areas near the centre of the galaxy where many millions of stars are bunched together.
If the lensing star is a single star it forms is a symmetrical lens so that it appears to brighten and then fade smoothly. If, however, the lensing star has an orbiting planet there are distortions in the shape of the lens and in the brightness curve as the source star passes behind. Auckland Observatory is part of an international collaboration called MicroFun – Micro Lensing Follow-Up Network – that picks out microlensing events that could be suitable for detecting a planet and then arranges for intensive 24-hour coverage through the various observatories that are part of the network.
Auckland Observatory uses a Meade 40-cm telescope on a solid Paramount mount. Once the observatory receives a request it uses the telescope on every available clear night to continually take images of the target star. At the end of each night of observing the images are sent to Ohio State University, the headquarters of MicroFun, where the images are processed to yield brightness measurements, merged with data from other observatories and the brightness curve is put together.
MicroFun has now detected a number of planets including one in April 2005 with a mass three times that of Jupiter and soon afterwards another with a mass similar to Neptune. This is cutting edge science and it is highly admirable for a small institution like Auckland Stardome, with its relatively small telescope, to have a major involvement.
The northern sky over Anzac Cove at 3:00 am EET on 25 April 1915. Calculated with the Stellarium planetarium program
On 25 April each year in Australia we commemorate the landing by Australian and New Zealand troops at Anzac Cove in Turkey. To try to gain some advantage of surprise over the enemy the landing had to be carefully coordinated with the time of moonset and sunrise. Here we look at how those times matched the events of the landing.
All calculated times are in Eastern European Time (EET) which is two hours east of Greenwich. That is the appropriate time zone and, as far as I can ascertain, that is the time zone used by the military for the landing. Note though that back in 1915 watches were not coordinated amongst the navy and army personnel and, in any case, would not necessarily be running exactly on time.
That night the Moon was gibbous, two and a half days after first quarter phase, so it was fairly bright. It set at 2:57 am.
The first report on the landings was by war correspondent Ellis Ashmead-Bartlett. It appeared in the Hobart Mercury on 12 May 1915. Here are a few extracts with inserted comments in square brackets:
“As the moon waned [he meant was setting], the boats were swung out. The Australians received their last instructions, and these men, who only six months ago were living peaceful, civilian lives, began to disembark on a strange, unknown shore, and in a strange land to attack an enemy of a different race.”
“At 3 o’clock it was quite dark [the Moon had set], and a start was made towards the shore with suppressed excitement. Would the enemy be surprised, or be on the alert?”
“Not a sound was heard, not a light seen, and it appeared as if the enemy had been surprised. In our nervy state the stars were often mistaken for lights ashore.”
No wonder that the stars were mistaken for lights as they would have been unfamiliar constellations and stars for the Australians. As indicated in the diagram above, in the northern sky they could see Ursa Minor or the Little Bear as well as Ursa Major or the Great Bear plus the ‘W’ of Cassiopeia. These are all well-known star groups in the northern hemisphere, but either not seen or not seen well from Australia.
Nautical twilight – that is the time when the horizon starts becoming visible – began at 4:21 am. Civil twilight – when lights can be switched off for outdoor activities and possibly dawn in this context – was at 4:55 am. The Sun rose at 5:24 am. Thus the opportunity for surprise only lasted until shortly after 4:00 am though at the same time the light started becoming sufficient for the landing.
“The progress of the boats was slow, and dawn was rapidly breaking at 4.50 when the enemy showed alarm for a light which had flashed for ten minutes then disappeared. The boats appeared almost like one on the beach. Seven torpedo-boat destroyers then glided noiselessly towards the shore.”
You can read more of Ashmead-Bartlett’s report here. We will finish with an extract from Laurence Binyen’s famous poem:
They shall grow not old, as we that are left grow old:
Age shall not weary them, nor the years condemn.
At the going down of the sun and in the morning,
We will remember them.
Sunspot group AR11429 first appeared at the sun’s east limb on March 3 (2012) as a compact “Island Delta” group that, much evolved, finally passed behind the western limb on the 15th – after strong flaring. At the time we noted that “Island Delta” groups were the most active sunspots – but were also short-lived ones. Would it return at the east limb in late March?
During its two weeks behind the sun several CME’s erupted at the spot‘s location – suggesting it might reappear. March 30 showed bright faculae at the east limb – but no spots. March 31 however, showed more faculae at the site (now 30º onto the disc) and two dark filaments stretching N-S through it. Finally, with high magnification, two tiny spots were detected (Fig 1, LHS). AR 11429 had survived a full rotation of the sun – but only just! NOAA promptly dubbed the returnee AR 11451.
Filaments: While the tiny spots were gone by April 3, the filaments had grown into the most striking feature on the disc (Fig1, RHS), compared to the other small groups present (not shown).
For amateurs, filaments are only visible in H-alpha (and in satellite EUV bands). They are magnetic “channels” between surface fields of opposite polarity where cooler material collects; they come in two kinds: active region filaments and quiet region filaments. This filament was a mixture of both!
Helio freeware sited the darkest part of the big filament between +20º, 302 and +11º, 311 with a “tail” northwards. These points were very close (~5º) to the inversion line that bisected spot group AR11429 a month before: the stage was set for spotless flares (Zirin, H. “Astrophysics of the Sun” PP 221 and 333).
AR11429 had been (briefly) an “Island Delta” class with mixed and reversed polarities in one penumbra, but when it evolved into a larger simpler group it remained fully reversed. Mt Wilson’s daily magnetogram (Fig 2) now showed that regions of reversed polarity persisted at the old sunspot site, little changed from the previous rotation (Fig2. Black line is the filament site). And the low power fields still showed concentrations of stronger field where the main spots had been during the previous transit.
Although now spotless, the old AR11429 site did have more flares – but not big ones, mostly along the filament channel that a month earlier had separated the spot group’s opposite polarities.
The magnetogram also showed that the whole active area now stretched across 45º of longitude with three attached active regions; new “normal polarity” groups AR 11450 and AR 11452 (both small), with reversed AR11451 (old 11429) in between. Some unusual coronal links between new and old spots were seen in SDO EUV images of the region.
Filament Ejection: A small ejection at the south end of the big filament erupted on April 3rd. While stable from 21:48 to 22:56, at 23:02 a small globule ejected that was only seen ‘off central band’ H-alpha (Fig1, detail). This was tracked as it moved westwards– always ‘off band’, and invisible ‘on band’. This was likely part of the large filament that, while showing small lateral motion (6º in total, and dividing at b, 23:16UT), was ejecting along the line-of-sight at high velocity. The filter’s tuning range is stated to be ~10Å; assuming a -5Å shift the ejection velocity was 250km/s in approach. Meanwhile, the big filament remained stable. Since it seems to be the product of active and quiet region fields the potential is for a big ejection of this filament – spectacularly at the limb perhaps. Here’s hoping!
AR11429 (aka 11451) was by now only a ghostly manifestation of its younger self – with no spots, just the wraith-like filament and its recurrent flares – yet there in the magnetogram were signs of the once majestic spot group: the largest reversed group yet of SC24.
Harry Roberts is a Sun and Moon observer, a regular contributor to the Sydney Observatory blog and a member of the Sydney City Skywatchers
As a young postgraduate student I gave my first professional talk on the possible origins of the Moon. At that time there were three main possibilities: the fission theory that somehow the still molten Earth split into two and the Moon flew off; the twin planets theory that the Earth and the Moon somehow formed separately at the same time and at the same place; and the capture theory that the Earth captured a passing asteroid that became the Moon. All of these theories had difficulties in matching the observed facts. For instance, to capture a passing body a huge amount of energy would have to be dissipated. I spent much of the talk arguing, probably unconvincingly, that the energy dissipation could happen under some very special and improbable circumstances.
Since 1975 a new theory has superseded the previous ones, solved most of their problems and has been widely accepted by the scientific community. According to this theory in the early days of the solar system there were still many Mars-size objects circling the Sun and one of those struck the Earth. This impact would explain the relatively fast spin of the Earth as well as its tilt of 23½° that is responsible for the seasons. In recent years the impactor has acquired the name Thea.
During the impact Thea’s metal core would have merged with that of Earth while the outer layers (mantles) of both objects would have been thrown into orbit around the Earth. Over a time of less than a century and possibly much quicker, this material would then have coalesced to form the Moon. This scenario would explain the Moon’s lack of the extensive iron core that most other similar and larger objects in the solar system possess.
Recently, a few problems have arisen with the current version of the impact theory. Calculations suggest that over 40% of the Moon’s material would have come from Thea, yet there are indications based on examining the oxygen in samples brought from the Moon that the lunar material is identical to that on Earth. To make the comparison scientists examined the ratios of different versions or isotopes of oxygen in lunar material and found that the ratios are identical to those from Earth.
Another study looking using titanium isotopes this time was published in Nature Geoscience on 25 March 2012. In a paper titled The proto-Earth as a significant source of lunar material five authors led by Junjun Zhang of the University of Chicago find that the titanium isotope ratios that they examined from lunar samples were the same as those from Earth to four parts per million. All this suggests that either that the Earth was the Moon’s sole parent and it was formed only from Earth material or that the material from Thea was so thoroughly mixed with that of the young Earth that it is now indistinguishable.
These results create problems for the current version of the impact theory. The theory is not dead, but scientists will clearly need to modify it considerably in the light of these new and intriguing results.
A rare picture of William John MacDonnell sitting in front of his newly installed 4¾-inch (12.1-cm) lens telescope by Parkes of Birmingham on 15 December 1907. Picture courtesy Powerhouse Museum
The amateur group associated with Sydney Observatory, the Sydney City Skywatchers, has a significant lens telescope that is associated with two significant people. The telescope was donated to the group under its original name, the New South Wales Branch of the British Astronomical Association in 1924 by Ernest Henry Charles Wunderlich. Hence today the telescope is known as the Wunderlich Telescope.
Photograph of Mr Ernest Wunderlich in 1909. Picture courtesy of the Powerhouse Museum
Ernest Wunderlich did not just donate the telescope, but his entire observatory and its contents including a small transit instrument and a chronometer. At the time the Sydney Morning Herald called the donation, ‘a munificent gift’:
Mr. Ernest Wunderlich, F.R.A.S., founder and chairman of directors of Wunderlich, Ltd., has given to the New South Wales branch of the British Astronomical Association, of which he is vice-presldent, his private observatory, as well as the building Itself, for the use of amateur astronomers in Australia.
It is a munificent gift in the cause of science.
The Herald article refers to the telescope as a ‘Cooke telescope’. This maybe because James Parkes & Son of Birmingham did not manufacture the lenses of their telescopes and the lens for this telescope may have been made by T Cooke & Sons.
Wunderlich was a successful businessman who had arrived in Sydney in 1885 at the age of 26. In 1908, together with his two brothers, he founded Wunderlich Ltd that made pressed metal ceilings and terracotta tiles. The firm continued to operate until 1969 when it was taken over by Colonial Sugar Refining Co. The Powerhouse Museum has a large collection of items and records from the firm’s old works at Redfern in Sydney.
Ernest had many interests outside his business including music and he helped to found the New South Wales State Conservatorium of Music as well as being president of the trustees of the Australian Museum at one stage. By 1915 Ernest had caught the ‘astronomical fever’ and became involved in astronomy. To provide himself with suitable instruments, he purchased the telescope and observatory that had belonged to the amateur astronomer William Macdonnell and set up the observatory at his holiday home at Gunnamatta Bay, Port Hacking. After using the equipment for a few years he must have wanted more time to pursue his other interests and hence donated it all to amateur astronomers.
William John Macdonnell, whose equipment was purchased after his death by Ernest Wunderlich, was a leading amateur astronomer of his time. He was a banker by profession and in 1882 he was promoted to branch manager at Port Macquarie in NSW. In 1874 he was one of the astronomers involved in observing the transit of Venus under the direction of Henry Chamberlain Russell of Sydney Observatory.
At one stage of Macdonnell’s life he had to sell his main telescope, but he replaced it between August and November 1907 with the 4¾-inch (12.1-cm) Parkes telescope. This telescope was mounted equatorially so that it could follow the motion of stars and it had a clock drive that was locally made by a local instrument maker E Esdaile.
We know of a number of observations that Macdonnell made with this telescope: on 11 January 1908 he observed Saturn’s rings as they were almost edge-on. On 6 April 1909 with his wife he observed an occultation and eclipse of Jupiter’s satellite Ganymede. On 19 April 1909 he observed Comet Morehouse and on 1 December of that year he had his first view of Comet Halley. On 4 November in 1909 he observed Mars and saw a white spot about 25° from the south pole of the planet.
William McDonnell could not make further observations with his new telescope as he died in September 1910 aged 67.
The Wunderlich Telescope in its long history has had connections with a leading Australian amateur astronomer and a highly successful Australian industrialist. The telescope is thus of great historical significance and it is to be hoped that its current custodians the Sydney City Skywatchers will find a suitable permanent depository for the telescope.
Orchiston, W., ‘William John Macdonnell and the development of astronomy in New South Wales’, Journal of the British Astronomical Association, 111, 1, pp13-25 (2001)
The paths of Mars and the Earth around the Sun with the positions of the 2012 and 2003 oppositions indicated. Drawing Nick Lomb
Every two years or so the red planet Mars is at opposition, when it is on the opposite side of the Earth to the Sun. At such times the planet is relatively close, but some oppositions are more favourable than others. The coming opposition in early March 2012 is a particularly unfavourable one, yet it is still worth looking for Mars with the unaided eye or examining it through a telescope.
The changing distance between Mars and Earth at oppositions is mainly due to the oval-shaped path of Mars around the Sun. The spectacular Mars opposition of August 2003 when the red planet was only 56 million km from Earth took place when Mars was near perihelion, its closest distance to the Sun. Conversely, at the current opposition the distance of Mars from Earth will be 101 million km, almost twice the distance in 2003, as Mars is near its aphelion, its furthest distance from the Sun.
Mars is at opposition on Sunday 4 March at 7:10 am. Interestingly, Mars is not at its closest to Earth until two days later on Tuesday 6 March at 4:00 am when it has moved about 60 000 km closer to Earth. The time difference between opposition and when Mars is actually at its closest is again due to the oval shape of the path of Mars around the Sun.
Favourable oppositions of Mars take place in a cycle of around 17 years. The last favourable one was in 2003 and the next one will be in October 2020. The best known favourable opposition of Mars was in September 1877. That opposition allowed American astronomer Asaph Hall to discover the two tiny satellites circling Mars using the large 26-inch (66-cm) lens telescope at the US Naval Observatory in Washington DC. He named the two moons Phobos meaning Fear and Deimos meaning Flight.
Another observer in 1877 was the Italian astronomer Giovanni Virginio Schiaparelli who made careful observations of the planet during the opposition in order to draw a a new map of its surface features. On his map he included some linear features that he called ‘canali’, which in Italian can mean natural features. However, the word was translated as ‘canals’ in English and so began a whole culture of belief in intelligent beings on Mars or Martians.
Oppositions of Mars are useful not just to provide the best times to examine the surface of the planet, but they also provide opportunities to launch spacecraft towards it with the minimum expenditure of energy and so fuel. Spacecraft to Mars are launched into a Hohmann Transfer Orbit before opposition and reach Mars eight and a half months later.
Finding chart for Mars in the eastern sky calculated for 9:30 pm on 5 March 2012 as seen from Sydney. Drawing Nick Lomb
Although the March 2012 opposition of Mars in not a favourable one it is still worth looking for it in the night sky. As indicated in the diagram above in the early evening Mars is low in the eastern sky near the bright sky Regulus. It is the brightest object in that part of the sky and with its red colour is quite unmistakeable. Through a telescope some features including its north polar cap should be visible. Good observing!
The ‘Leviathan of Ballarat’, now known as ‘The Baker’, is a 66-cm (26-inch) reflecting telescope completed in 1888. Photo Nick Lomb
Recently, on 10 February 2012, I visited the Ballarat Municipal Observatory at Mt Pleasant, Ballarat to give a talk on the transit of Venus. At the start of the visit Judith Bailey, the director, showed me around the observatory and I was amazed at the number of telescopes that are there and still in operation.
Looking into the tube of ‘The Baker’ towards the 66-cm mirror. Photo Nick Lomb
Ballarat Observatory opened on 11 May 1886 thanks to the generosity of the successful local businessman James Oddie and ‘Captain’ Henry Baker became the first director. At the time Baker was already 70 years old, but his telescope making skills, as shown by a prize-winning telescope he had exhibited at the Melbourne Exhibition in 1873, were such that he was the obvious choice for the post.
Baker had been a seaman who, like many at the time, came to try his luck on the Victorian gold fields in the 1850s. Although he did try prospecting for gold, with his technical skills he also manufactured mining machinery.
Despite his age Baker justified his appointment by embarking on a project to make a 66-cm (26-inch) reflecting telescope. He shaped the mirror in the observatory’s workshop using a grinding machine that he had designed and even the original tube and mounting were produced in a foundry at the observatory. When the telescope was completed in 1888 it was the second largest telescope in the country and was only eclipsed by the 122-cm (48-inch) Great Melbourne Telescope.
After producing this large size telescope Baker did not rest on his laurels for the metal mirror of the GMT needed repolishing. Robert Ellery, the director of Melbourne Observatory, invited him to assist and Baker spent October 1888 polishing the giant mirror. He returned in March and October 1889, but was unsuccessful in the tricky effort to bring the brittle metal to the correct smooth shape. Sadly Baker died the next year.
The original purpose of Ballarat Observatory was public education and this is still the task for the observatory today. In maintaining the telescopes the director is assisted by an active group of amateurs, the Ballarat Astronomical Society.
The Federation Telescope, a 41-cm (16-inch) telescope with a fixed eyepiece. Photo Nick Lomb
Telescope making is still happening at the observatory. In 2000, with the help of a Commonwealth Federation Community Projects Program Grant, a 41-cm (16-inch) telescope was added to the Observatory’s telescope menagerie. Designed by Barry Adcock, the current president of the Astronomical Society of Victoria, this Federation telescope has an unusual design with a stationary eyepiece. This feature makes the telescope usable by people in wheelchairs or by people who otherwise lack mobility.
The dome of the Jelbart telescope. Photo Nick Lomb
During my visit the locals complained of light pollution affecting the sky. They did say, however, that the Magellanic clouds are still visible. For those of us living in cities where the Milky Way and the Magellanic clouds are now a distant memory, that makes the location a relatively dark site.
The Jelbart Telescope is a 12.5-cm (5-inch) lens telescope that was donated to Ballarat Observatory in 1918 by the local firm, Jelbart Brothers. Photo Nick Lomb
Ballarat Observatory is open on Friday and Saturday evenings. As well as viewing through the telescopes when the sky is clear, there are 3D movies available and even meals and supper on occasion. For anyone visiting the area, possibly with the main aim of going to the Sovereign Hill, open-air museum, the observatory is definitely worth a visit.
References
Features of the Ballarat Municipal Observatory, Ballaarat [old spelling] Astronomical Society, 2001
Amateur Telescope Making in Australia, an historical perspective, Wayne Orchiston, ATM Journal 15, 2000 pp10-26
In this photograph from the early 1900s, the stone survey marker in front of Sydney Observatory is surrounded by what appears to be an uncompleted wooden platform. The white thermometer shed is adjacent to the survey marker while the Observatory’s meteorological instruments can be seen on the lawn behind it. The large structure on the left is the dome for the astrographic telescope that was still standing, although the telescope itself had been moved to Pennant Hills. Photo Powerhouse Museum
The historic stone pyramid that stands in front of the Observatory is a survey marker or trig station. It is marked as the latter in an 1880 plan of the Observatory drawn up by its then director, Henry Chamberlain Russell. In the plan the trig marker is drawn as circular suggesting that the timber platform seen in the image above was a permanent structure.
A detail from Henry Chamberlain Russell’s 1880 map of Sydney Observatory and its surroundings. The survey marker is denoted as Trig Statn and is drawn as circular. Powerhouse Museum
The marker stands on the Sydney meridian, which is the line passing through the Observatory’s Transit Circle Telescope and running north-south. By observing stars, astronomers using the Transit Circle could establish both its longitude – how many degrees it was located to the east of Greenwich Observatory – and its latitude – how many degrees it was to the south of the equator. Thus the longitude of the survey marker was precisely known and its latitude could be easily calculated from the slight offset in distance from the telescope just inside the building.
This stone marker with its highly accurate position would have been essential for 19th century surveyors to use in any surveys of Sydney. The accurate position of the marker would have ensured that their surveys for property boundaries or sewage lines were also accurate.
The platform with steps leading up to it suggests that surveyors would climb to the top of the marker with their theodolites and measure angles to landmarks that were visible. With these angles they could use triangulation or trigonometry to draw up their maps.
The small triangular marker for Trig Station E that was on top of the tower of Sydney Observatory. Powerhouse Museum
As the area around the Observatory became built up in the late 19th and early 20th centuries, gradually the view of distant church steeples and other landmarks would have been lost. Presumably this explains why a new survey marker was placed on the top of the Time Ball Tower, from where surveyors had excellent views over most of Sydney. It is not known when Trig E was first placed on top of the tower, but the existing marker in the collection of the Powerhouse Museum is inscribed: REFIXED/SUR. RICHMOND/[1927]/TRIG STN./E.
Surveyors were still using Trig E in the late 1970s and early 80s. They would have to haul their theodolites up the steep stairs to the top of the tower. The main concern of the Government Astronomer in charge of the Observatory was that the spikes at the bottom of their theodolite tripods could damage the flat roof of the tower and the surveyors had to promise to ensure that that did not happen.
In the 1980s surveyors stopped using Trig E and the marker was removed during a subsequent refurbishment of the roof of the tower.
Recently, at the request of the Observatory, staff from the NSW Department of Lands replaced the survey marker on top of the tower and re-established its position with the latest GPS techniques. Now known as Observatory E, its coordinates are:
Latitude 33° 50′ 55” S
Longitude 151° 12′ 4” E
Buried deep in the archives of Sydney Observatory and the NSW Department of Lands there is probably much more information on the stone survey marker than outlined here. In the meantime though if there are any surveyors out there who know more of the story, or used Trig E in the past, please make a comment on this post or contact Sydney Observatory. Any information would be much appreciated.
An Australian Post Office film about the arrival of the first automatic speaking clocks in Sydney and Melbourne in 1954. Thank you to vk3ase for finding and posting this film on YouTube
Today everything is small and electronic. Our watches with their quartz crystals keep the time to a few seconds a day and we can obtain the time to even greater accuracy using smart phones. These devices provide convenience and functionality, but we have lost the wonderful and complex ingenuity of the past. Mechanical watches with their escapements and moving balance wheels were treasured items of beautiful intricacy. Unlike the situation today, with a little application their workings could be understood and admired.
The time provided on the telephone by ringing 1194 is today all electronic, although wonderfully it appears to be the same voice as back in 1954. As shown in the video above, that year saw the arrival and installation of the automatic Speaking Clock, affectionally known as George, in Australia’s two main cities, Sydney and Melbourne . This clock was a marvel of engineering that synthetised the time from three different optical discs. Sound tracks were recorded like in movie films as brightness fluctions on the discs. In use the discs were ‘read’ by using photoelectric cells that converted the brightness variations to voltage fluctuations. Australian actor Gordon Gow recorded the sound on the discs.
The Sydney clocks were housed in the GPO in Martin Place; there were two – one operating and the other serving as backup. When they were retired and replaced in 1990, one of them came to the Powerhouse Museum after restoration by a technician in his spare time. For a number of years George the Speaking Clock was on display at Sydney Observatory as an interactive exhibit. Visitors could press buttons to hear the fully synthetised time or only part of the sound track.
The door of the speaking clock room at the old GPO in Martin Place is also part of the Museum’s collection. Courtesy Powerhouse Museum
George is now carefully stored at the Powerhouse Discovery Centre at Castle Hill and is shown occasionally on open days. Hopefully, in a few years, there will be suitable exhibition at the Museum and visitors once again will be able to admire the clock’s wonderful ingenuity.
Toner Stevenson, Manager Sydney Observatory, reports from Western Australia.
My recent visit to Perth included visiting the Observatory at Bickley. Not only was I treated to a fabulous lunch prepared by and shared with all the observatory staff, there was the opportunity to go behind the scenes with acting Director, Ralph Martin, astronomer Dr. Andrew Williams and education manager Greg Lowe.
Perth Observatory, the 1896 foundation stone is on the lower right side. Photo T. Stevenson, 2011
On approach up the long driveway that separates Perth Observatory from Bickley’s suburban sprawl the first thing I noticed was the foundation stone dated 1896 in front of a clearly 1960s modernist building. This stone, laid by John Forrest, marks the first Perth Observatory building established in Kings Park, close to what is now the city. Like Sydney Observatory during the late 1800s, the observatory was the colonial centre for astronomy, timekeeping, meteorology and surveying, covering the vast state of WA. Over time these functions were mostly removed or reduced significantly, and in 1965 Perth Observatory was relocated to the suburb of Bickley, about 40 minutes outside Perth. Fortunately more than the original foundation stone was relocated from the city site as I soon discovered. Many significant items of a past era shared with Sydney Observatory have been carefully kept and some were still in use. From the minute I stepped through the door I sensed the strong ties between Perth and Sydney Observatories re-connecting, it felt like catching up with a dear friend.
William Earnest Cooke (seated left) Director of Perth Observatory, pictured with Yeates, Curlewis, Ackland and Jocelyne in front of Old Perth Observatory, 1901. Courtesy Perth Observatory Collection.
The astronomer and meteorologist William Earnest Cooke was the first Western Australian Government astronomer (1896 to 1912) and in 1912 he accepted the Directorship of Sydney Observatory. It was through Cooke’s initiatives that in 1900 Perth Observatory undertook work on the Astrographic Catalogue and Carte du Ciel. Both Sydney and Melbourne observatories had already begun work on this ambitious international project to catalogue and chart the entire sky. Like Sydney, Perth Observatory has an active public day and night tour program , publishes an annual astronomy almanac and supports its heritage work through an adopt a star program, drawing on its own catalogue of stars also providing recipients the opportunity to view their star.
Perth’s astrographic telescope by renowned Irish instrument maker Howard Grubb is in impressive working order and Greg Lowe showed me how this is demonstrated as part of the regular night tour. Designed to photograph the stars, this telescope was the standard chosen for use by the British Observatories participating in the Astrographic Catalogue. Sydney Observatory’s ‘star camera’, a unique telescope design by Henry Chamberlain Russell, had only the lens supplied by Grubb. But the Melbourne Astrographic telescope, moved to Sydney Observatory in 1948, appears almost identical to the one in Perth. These instruments are in the Castle-Hill store pending conservation. The original Perth Astrographic dome was removed from the 1896 building and relocated to Bickley. It is one of a number of telescope domes, some of which are made accessible to the public. This restored 1910 Calver (Newtonian) telescope can be compared to the view through the contemporary 40cm MEADE Schmidt Cassegrain.
Acting Director, Ralph Martin with the 1910 Calver (Newtonian) telescope used during night tours. Photo T. Stevenson, 2011
This site is a living astronomy archive with a comprehensive astronomy library, extensive glass plate negative collection, heritage instruments and a complete set of Astrographic Catalogues. An exhibition displays some of the treasures from their collection and is well worth a visit. At night you can experience the night sky from a relatively dark sky environment through telescopes.
Perth Observatory is the only State-run Observatory still equipped and staffed for research and as such the public are also able to witness science in action. High up on a 15metre tower is the primary research telescope and largest dome on the site. The Perth-Lowell automated telescope is operated remotely and has a sensor that closes the dome in wet weather. Ralph Martin spoke about the partnerships Perth Observatory has formed with Universities, major projects such as ICRAR (International Centre for Radio Astronomy Research) and Perth Observatory’s gravitational micro-lensing work which has led to the discovery of smaller planets rotating around distant stars. You can take a virtual tour of the Perth-Lowell observatory without climbing all the stairs.
Astronomer Dr. Andrew Williams with the Perth-Lowell telescope. Photo T. Stevenson.
I also visited the Old Perth Observatory, a grand residence for the Government Astronomer. With 2012 the centenary of W.E. Cooke’s departure from Perth to the Directorship of Sydney Observatory expect other blogs to follow throughout the year.
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The 'Observations' blog is run by the staff of Sydney Observatory which is located at Observatory Hill, The Rocks, in Sydney, Australia.
This site is for discussion purposes only and does not represent the official views of Sydney Observatory. Any views expressed on this website are those of the individual post author only. Sydney Observatory accepts no liability for the content of this site.
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