PERTH OBSERVATORY NEWSLETTER
EDITOR'S NOTE by James Chesters June 2021 Welcome to the Winter Solstice edition of the Perth Observatory newsletter. We're thoroughly into the season of Makuru, undoubtedly the coldest and wettest time of the year. Luckily, our amateur astronomers are wrapping up warm to show you what's in the starry southern sky through our telescopes.
PERTH OBSERVATORY 337 Walnut Rd Bickley WA 6076
Learn what's where and when in the night sky from the master Matt Woods. Read on and find out what's up every month – including two meteor showers, the beautiful double star Albireo and various galaxies and nebulas. Elsewhere in this edition, CSIRO welcomes us for a visit to the European Space Agency's deep space ground station, Carol Wolf (Perth Observatory's librarian and archivist) talks about preserving over 100 years of historic paper-based records, and Paul Wadham updates us on projects at Perth Observatory. And on the subject of our amazing volunteers, we're recruiting now for both School Day Tours and Administration help – so get in touch if you want to join the team at Perth's oldest observatory! Perth Observatory Volunteer Group acknowledges we operate on the traditional lands of the WhadjukNoongar people. Kalamunda has been an important meeting place for Noongar people, from pre-contact to the present day, and our local area contains significant campsites and spiritual sites. POVG pay our respects to these Elders past, present.
CONTACT US Perth Observatory PO Box 179 Kalamunda WA 6926 (08) 9293 8255 newsletter@povg.org.au www.perthobservatory.com.au
CONTRIBUTORS
Contents
Editor-in-Chief
Trifid And Lagoon Nebulas
James Chesters
Contributors Carol Wolf Colin Armstrong Jay Chesters Julie Matthews Matt Woods Paul Wadham
This July, see the Trifid Nebula and Lagoon Nebula in our starry southern skies.
WA Calling jupiter We visit the New Norcia Deep Space Ground Tracking Station.
zodiacal light season begins
As the Sun approaches the September Equinox, the Zodiacal light season begins on September 1.
Subscribe Click below to subscribe to the newsletter.
perth observatory's fairy doors
Visit us to find the six magical fairy doors on the grounds of Perth Observatory.
Come on, Get Social
POVG CHAIR DR COLIN ARMSTRONG Winter is one of the best times for stargazing in our great southern land! Thank you to Matt Woods for sharing with us in this Newsletter the many sights to see in the sky over the next few months. After last year's lockdown, not to mention a couple this year, it's heartening to regularly welcome so many visitors to Perth Observatory. On top of our Winter Night Tours three times a week, every Sunday we greet dozens of eager visitors to Perth Hills for our daytime guided tours. As well as showing off our majestic Meridian, Astrograph and Calver Telescopes, visitors take in our beautiful surroundings and our various imaginative fairy doors. There's no need to book to join us on a day tour every Sunday for stories of the observatory from our Mt Eliza days, our move to Bickley in 1966, what we’ve been doing since then, and what's in the pipeline for Perth Observatory. You read in the last edition of the Newsletter that the State Government promised the observatory $1.6m funding to support our general operations and expand our STEM education programs. Since then the real work has begun!
The POVG board is busy consulting stakeholders, consolidating identified needs and preparing budgets for the 1st Year’s Budget Submission. Our STEM work doesn't end with astronomy, either! We're currently conducting a Bird Census of the Perth Observatory site. The first of these 20-minute observations identified 11 species and recognises many others that will be identified over time. We'll make collected data from this bird census available through our website, as will other data including the results of a reptile census. There's always a lot happening at Perth Observatory! Thank you for supporting Perth's oldest observatory, I hope we'll see you soon.
PERTH OBSERVATORY
WINTER NIGHT TOURS
The best time for viewing our southern skies is during winter. Perth Observatory's passionate volunteers brave the cold to show you planets, and the galactic centre passing overhead revealing many deep-sky treasures that you can’t see in Summer. Read Matt Woods' expertly researched articles to find out 'What's Up in the Sky' or just pick a night to join us! Alpha Centauri is highest from March to September, and Omega Centauri is easily seen from April through September. Our night sky tours often sell out, so book yours in advance. Find out more and check availability here: perthobservatory.com.au/night-tours/winter-night-tours
BOOK NOW
STAR ADOPTION TOURS Perth Observatory's unique star adoption program includes a gift certificate and private viewing tour as a way to recognise a family member or friend. All available stars in the adoption program range between the magnitudes -1 and 4.9 (visible to the naked eye) or 5.0 and 7.9 (visible in binoculars). All stars are visible in the Southern Hemisphere. Your individual star adoption package includes: A certificate (suitable for framing) with your adopted star's name and coordinates, and the duration and purpose of the adoption. A private star and night sky viewing tour for the recipient and three guests within 12 months. This includes viewing your adopted star, along with several other night sky objects. The tour is scheduled when your chosen star is available at a suitable time for viewing A planisphere (a device to show what constellations and stars are in the sky at any given time) Star charts and coordinates showing where to find your star in the night sky, as well instruction on how to use these on your star viewing night Please note: Perth Observatory's Star Adoption program doesn't offer international naming rights to your adopted star because there are no internationally-recognised naming rights. The Perth Observatory Volunteer Group Inc runs the star adoption program, and proceeds go towards the observatory's not for profit public outreach program.
FIND OUT MORE
WHAT'S IN
JULY'S NIGHT SKIES by Matt Woods
Mercury is visible very low in the eastern sky until mid-July, appearing in the constellation of Taurus (The Bull). Reaching its greatest elongation in the east on July 5, Mercury moves into Gemini (the Twins) as it makes its way back towards the Sun and disappears in the Sun's glare. Venus and Mars are low in the western sky during July. Both planets start the month in Cancer (the Crab) but move into Leo (The Lion) as we move through July. At the start of the month, Venus sets at 19:19 (AWST) and Mars sets at 19:52, and by the end of July, Venus is setting at 20:12, and Mars at 19:23.
Jupiter rises at 21:21 at the beginning of July, and Saturn rises at 19:48. By the end of July, Jupiter is rising at 19:11, and Saturn is rising before sunset. Uranus is in Aries in the early morning this month, rising at 03:02 at the beginning of July. By the end of the month, Uranus is rising at 01:08. Neptune is viewable in the early morning this month, between Aquarius and Pisces. Neptune rises at 23:00 at the start of July, and by the end of the month, it is rising at 21:01.
Jupiter and Saturn are in the east in the late evening sky this month, Jupiter is in Aquarius (the Water Bearer), while Saturn is in Capricornus (The Sea-Goat) throughout July.
All images credit: Stellarium
Mercury on 15/07/21 at 06:30
Mercury's greatest elongation in the east on 17/05/2021
Venus and Mars on 15/07/21 at 18:00
Jupiter and Saturn on 15/07/21 at 11:00
Uranus and Neptune on 15/07/21 at 05:00
Trifid and Lagoon Nebulas. Image Credit: Perth Observatory Volunteer Andrew Lockwood
OBJECT OF THE MONTH
by Matt Woods
TRIFID AND LAGOON NEBULAS
The Trifid Nebula (M20 & NGC 6514) and Lagoon Nebula (M8 & NGC 6523) appear close together in the constellation of Sagittarius. Approximately 2,660 light-years away and 15 light-years across, the Trifid Nebula is an emission (pink) and reflection (blue) nebula, with an open star cluster. The Trifid (meaning "divided into three lobes") comes from the three-pronged dark lanes (dark nebulae) through the nebula that blocks off the light behind. Hot young stars in the central star formation "nursery" power the emission nebulae, and infrared telescopes show around 30 embryonic and 120 newborn stars. The new stars are very young, around 400,000 years old, and not yet bright enough to emit light theatvisible light part of the light spectrum. The central star onin15/04/21 the atnebula is a cluster of Mars on in 15/04/21 19:00 Jupiter, Saturn and Neptune 05:00 four-star systems, two of which are close binary stars, so there are six stars altogether. The Lagoon Nebula is, sometimes called the "Hourglass Nebula" (not to be confused with the true "Hourglass Nebula" in the constellation of Musca), is a very young nebula, perhaps less than 10,000 years old. Further away than the Trifid Nebula, the Lagoon Nebula is 4,100 light-years away, and it's a lot bigger: about 100 light-years across and 50 light-years high. The Lagoon Nebula is one of the finest and brightest star-forming regions in the sky and contains many "Bok globules", dense cosmic dust and gas from which star formation may occur. The nebula's central emission area is energised by a bright ultraviolet "O4" class star, making it a relatively easy find for amateur astronomers.
A meteor from the Delta Aquarids. Image Credit: David S. Brown
ASTRONOMICAL EVENTS | JULY
DELTA AQUARIIDS METEOR SHOWER by Matt Woods The Southern Delta Aquariids meteor shower peaks on July 27/28, favouring the Southern Hemisphere, including Perth. Active every year from mid-July to August 23 in 2021, the Last Quarter Moon is near the constellation of Aquarius, so expect to see a reduced hourly rate (meteors per hour) for the Delta Aquariids meteor shower this year. The good news is that the Moon is waning during the first week of August 2021, so some Delta Aquariid meteors will intermix with the Perseid meteor shower. Radiating from the constellation of Aquarius, astronomers believe the sungrazing comet 96P/Machholz 1 is the source of the Delta Aquariids. Named after American amateur astronomer Donald Machholz, the comet's orbit carries it around the sun once about every five years. The peak of the Delta Aquariids meteor shower is from 20:00 on July 27, but the best viewing is around 03:00 on July 28.
The Delta Aquarids on 28/07/21 at 05:00. Image Credit: Stellarium
JULY
VIRTUAL STAR PARTIES hosted by Matt Woods
Tune in this July as the marvellous Matt Woods presents a livestream from one of our telescopes, showing off our amazing Southern sky. Join us! The virtual start party starts 20:00 (AWST). Click the links below and sign up. Lynds Dark Nebula 1251 Image Credit & Copyright: Ara Jerahian
Perth Observatory's Virtual Star Party
Wednesday, 3 July 2021 Register here - free!
Comet NEOWISE over Stonehenge Image Credit & Copyright: Declan Deval
Perth Observatory's Virtual Star Party
Wednesday, 14 July 2021 Register here - free!
JULY'S CONJUNCTIONS Conjunctions involve object(s) in the Solar System and/or more distant objects, such as a star. It’s an apparent phenomenon in which the observer’s perspective causes multiple objects that aren’t close together to appear close in the sky. This month you can see conjunctions between Venus and Mars, Venus and Regulus, and Mars and Regulus. Venus & Mars on 13/07/21 at 18:30
Venus & Regulus on 22/07/21 at 18:30
Mars & Regulus on 29/07/21 at 18:30
Astronomer Michael Candy: Director, Perth Observatory 1984-1993
BEHIND THE SCENES
PROJECT UPDATES by Paul Wadham, projects manager
After almost five years our Photographic Glass Plates Preservation Project is now finally complete. A huge thank you to everyone involved! As part of this epic program, we have scanned 22,872 plates. The project has preserved the analogue data saved on single copies of 6-inch square (16 x 16 cm) as well as 6-inch by 3.5-inch (16 x 6cm) photographic glass plates. Produced primarily during the period from 1901 to 1999 by the Perth Sir Howard Grubb Astrographic standard telescope, built in 1897 and installed in 1899, the plates have an image scale of 60mm per degree. The crew who started scanning in April 2018 were Mike Meyers, Suzanne Knight, Zoe Fraussen, Carol Korb, Alison Sampey, and myself, with Dr Craig Bowers as the project manager and Geoff Scott Tech support.
You'll remember from our last newsletter in March that these are needed to support the restored museum's restored clocks and timepieces.
Work has also commenced on the museum's walls, preparing them for painting. Kitchen renovation Back in March, we reported that our kitchen upgrade project was almost complete -- and I'm pleased to share that renovations are now complete! After months of hard work and dedication, the kitchen now has a new floor, and a replaced operable wall between the kitchen and the lecture theatre. That's not all, the kitchen now has a new dishwasher, and we've installed additional power sockets after needing to relocate the fridge and construct new cupboards to house the dishwasher and bins.
Congratulations and thank you to everyone who helped with the new kitchen!
Now the glass plates scanning is complete; the rest of the project is recording all the paper records associated with the plates, including metadata relating to the image recorded on the plate envelopes and in a series of observing books. Museum upgrade Work continues on the Perth Observatory museum upgrade, and I can share with you now that the underfloor concrete plinths are now in place. Underfloor concrete plinths in place in the museum
Inside the New Norcia Deep Space Ground Station Image credit: Jay Chesters
WA CALLING JUPITER by Jay Chesters The Jupiter Icy Moons Explorer (JUICE) will reach the gas giant in 2029 – with help from WA. 120km outside of Perth, I visit the unassuming New Norcia Deep Space Ground Station that sits quietly near the monastic town of the same name. Operated by CSIRO, the European Space Agency's station is equipped with one 35-metre dish and a sibling 4.5-metre dish for communicating with spacecraft after launch, in low earth orbit, in geostationary orbit and in deep space. Deep space Receiving signals across billions of kilometres of space, New Norcia supports ESA missions including Rosetta, the Mercury mission BepiColombo, and Mars Express – with more are on the way. A second 35-metre dish is already under construction at New Norcia. Super-cooled to almost absolute zero, the 620tonne antenna will provide ESA with crucial communication links to its growing fleet of deep space missions, including the Jupiter Icy Moons Explorer, as well as the Hera mission for planetary defence, and the Solar Orbiter (SolO) mission. Because spacecraft like Rosetta and JUICE have limited antennas, deep space missions require big antennas – all the better for receiving large amounts of data.
New Norcia's 35-meter dish NNO-1 Image credit: Jay Chesters www.AstroPhotography.com.au © Roger Groom
New Norcia's 35-meter dish NNO-1 Image credit: Jay Chesters
New Norcia's antenna is one of the largest in the world, with most of NASA's Deep Space Stations using paltry 34metre dishes. The farther out a spacecraft is, the bigger the dish needs to be. Suzy Jackson, Officer in Charge at the New Norcia Deep Space Ground Station, says the 35m antenna will be up and running before JUICE gets to Jupiter. JUICE launches June 2022. After 88 months of travel and a little help from five different gravity assists (where a spacecraft uses the relative movement and gravity of a planet to accelerate) the spacecraft will reach Jupiter around October 2029. "A lot of observation is needed in weeks before gravity assists," Jackson says, "they're very precise maneuvers."
Accuracy Jackson says the New Norcia Deep Space Ground Station uses its smaller, 4.5-m diameter antenna, NNO-2, to support Ariane, Soyuz and Vega launchers lifting off from ESA's spaceport at Kourou, French Guiana. After launch, a spacecraft is tracked by various ground stations before it comes into range for New Norcia. This can be terrifying. 90 minutes before launch, New Norcia switch from mains power to their enormous back up diesel generators, so there can be no risk of interruption. A spacecraft crosses the horizon in about 15 minutes – so there's no room for mistakes. JUICE will enter orbit around Jupiter's moon Ganymede in 2032, becoming the first spacecraft to orbit a moon other than Earth's. Keep watching the skies for JUICE's launch next year, and remember WA's important role in the mission.
Artist's impression of JUICE | Credit: ESA/AOES CC BY-SA IGO 3.0
www.AstroPhotography.com.au © Roger Groom
WHAT'S IN
AUGUST'S NIGHT SKIES by Matt Woods Mercury is visible very low in the western early evening sky from mid-August appearing in the constellation of Leo (The Lion) before quickly moving into the constellation of Virgo (The Virgin) and joining Venus. Venus and Mars are both visible low in the western early evening sky this August. The pair start the month in Leo, but go their separate ways as we move through August. Venus moves into Virgo while Mars stays in Leo and in mid-August enters the Sun’s glare.
Both Jupiter and Saturn are viewable throughout the night and reach opposition in August, with Saturn reaching opposition on August 2 and Jupiter on August 20. Uranus is in Aries (the Ram) in the late evening. At the beginning of August, Uranus rises at 01:04, and by the end of the month, it's rising at 23:03. Neptune is also viewable in the late evening between Aquarius and Pisces (The Fish). At the start of August, Neptune is rising at 20:57 and by the end of the month, it will rise at 18:55.
Jupiter and Saturn are in the eastern sky this August. Jupiter is in Aquarius (The WaterBearer) while Saturn is in Capricornus (The Sea-Goat) during August.
All Images credit: Stellarium
Mercury, Venus and Mars on 15/08/21 at 06:30
Uranus and Neptune on 15/08/21 at 03:00
Jupiter and Saturn on 15/08/21 at 08:30
Albireo. Image Credit: Palomar Observatory/STScI/WikiSky
OBJECT OF THE MONTH
ALBIREO by Matt Woods
Albireo is a double star 390 light-years away from us and is the "beak star" in the constellation of Cygnus, the Swan. The star takes its name from misunderstandings and mistranslations of Arabic, Greek and Latin. Although appearing as a single star to the naked eye, with even low-magnification telescopes Albireo resolves it into its two components, making it ideal for viewing with modest telescopes. Albireo is a good wide double star with strong colour contrast. The primary star, Albireo Aa, is bright yellow/amber in colour, its companion, Albireo B, is blue/green. Albireo Aa is also a close binary; however, it's too close and faint to detect without very large telescopes and excellent observing conditions. The two stars revolve around one another in about ~100,000 years. Albireo Aa is ~5 times the mass and ~1,200 times brighter than the Sun but has a cooler surface temperature of ~4,100K. The secondary star is ~3.2 times our Sun's mass and is hotter than Albireo Aa and the Sun combined, an average surface temperature of around 13,200K. Albireo appears low in the northern sky for only a few months during late winter and spring.
Albireo on 15/08/21 at 21:00. Image Credit: Stellarium
A meteor from the Delta Aquarids. Image Credit: David S. Brown
ASTRONOMICAL EVENTS | AUGUST
PERSEIDS METEOR SHOWER by Matt Woods The Perseids meteor shower peaks August 12/13. Connected with Comet Swift-Tuttle, orbiting the sun every 133 years, people have observed this meteor shower has for at least 2,000 years. Every August, Earth passes through the chunks of ice and dust left by the comet's tail, some parts over 1,000 years old. Around August 12 and 13, more than 100 meteors an hour from the debris field start hitting Earth's atmosphere, burning up and creating one of the best meteor showers of the year. For the Northern Hemisphere. All over the sky in the Northern Hemisphere, people with sharp eyes will see the meteors appear to come from the constellation Perseus, from where they take their name 'Perseids'. Unfortunately for the Southern Hemisphere, especially Perth, the meteor shower is very low on the horizon in the north around 06:00. We're lucky to see, at best, a couple of meteors per hour. It's a shame because people can see anywhere from 115 to 170 meteors per hour in the Northern Hemisphere. The Moon this year is a New Moon phase, so shooting star lovers don't have to worry about light pollution: go out and look north at 06:00.
The Perseids on 13/08/21 at 06:00. Image Credit: Stellarium
AUGUST
VIRTUAL STAR PARTIES hosted by Matt Woods
Tune in this August as the amazing Matt Woods presents a livestream from one of our telescopes, showing off our amazing Southern sky. Join us! The virtual start party starts at 20:00 (AWST). Click the links below and sign up. NGC 2442: Galaxy in Volans Image Credit & Copyright: Processing: Robert Gendler & Roberto Colombari Data: Hubble Legacy Archive, European Southern Observatory
Perth Observatory's Virtual Star Party
Wednesday, 4 August 2021 Register here - free!
Cygnus Skyscape Image Credit & Copyright: Alistair Symon
Perth Observatory's Virtual Star Party
Wednesday, 25 August 2021 Register here - free!
SUNDAY DAY TOURS See Perth Observatory in a new light - daylight! Sunday afternoons are the perfect time for joining your family and friends on a special Guided Day Tour of Perth Observatory. Our guided tours of the observatory start at 13:30, 14:00, 14:30 and 15:00 every Sunday afternoon, and include visits to our Astrograph, Calver and Meridian telescopes, as well as the majestic and historic Lowell telescope, and our Aboriginal Astronomy centre Worl Wangkiny, celebrating 60,000 years of Noongar celestial storytelling.
FIND OUT MORE
There's no need to book (but please tell us in advance if you're a group of 20 people or more so we've enough volunteers for you!) Find out more here: perthobservatory.com.au/tours/sunday-day-tours
PERTH OBSERVATORY ASTROSHOP
NEW ARRIVALS
Forgot your woollies? Warm up on our Winter Night Tours.
Stop into the astroshop next time you visit us and see what else has recently arrived.
WHAT'S IN
SEPTEMBER'S NIGHT SKIES by Matt Woods
Mercury is visible very low in the western early evening sky throughout September, appearing in the constellation of Virgo (The Virgin). The planet reaches its greatest elongation in the West on September 14 before it begins to make its way back towards the Sun. Venus is also in the western early evening sky and in late September it's moving into Libra (the Scales) from Virgo. Jupiter and Saturn are in the eastern evening sky, with Jupiter in Aquarius and Saturn in Capricornus.
Mercury and Venus on 15/09/21 at 07:00
Jupiter is setting at 06:06 (AWST) at the beginning of September and 04:04 by the end of the month. Saturn starts September setting at 5:10, is setting at 03:12 by the end of the month. Uranus is in Aries (the Ram) this month. Uranus is rising at 22:59 at the beginning of September and rising at 21:02 by the end of the month. Neptune is also viewable in the evening between Aquarius and Pisces. At the start of September, Neptune is rising at 18:51 and is viewable throughout the night by the end of the month.
Mercury's greatest elongation in the West on the evening of 14/09/2021
All Images credit: Stellarium Jupiter and Saturn on 15/09/21 at 07:00
Uranus and Neptune on 15/08/21 at 03:00
Uranus and Neptune on 15/09/21 at 00:00
The Sculptor Galaxy - Image Credit: Mike O'Day
OBJECT OF THE MONTH
THE SCULPTOR GALAXY by Matt Woods
The Sculptor or the Silver Coin Galaxy (NGC253) is a barred galaxy in the Sculptor constellation roughly 67,000 light-years wide. Sculptor Galaxy Discovered (by Europeans) by Caroline Herschel in 1783, while carrying out a comet search, Image Credit & Copyright: Mike O'Day it's one of the Sculptor group of galaxies, grouped around the south galactic pole (sometimes called "the South Polar Group").
The Sculptor group may be the next closest group of galaxies beyond our Local Group, located about 11.5 million light-years from Earth. Often called a Starburst galaxy, NGC253 contains many stellar nurseries, forming many hot young blue stars. This activity is from a collision with a dwarf galaxy approximately 200 million years ago, and the process of star formation and subsequent explosion as supernovae occurs at an unusually high rate. These young stars emit radiation that causes the hydrogen gas to glow brightly pink. NGC253 has many Wolf Rayet stars -- these are stars that start as hot, massive stars, around x20 solar masses, and rapidly lose mass by blowing their hydrogen envelope away in the form of highvelocity stellar winds. The Silver Coin Galaxy also has a large proportion of dust, although in less defined lanes, such as those found in the Milky Way galaxy. With an apparent magnitude of 7.2, the Sculptor is the second easiest galaxy to see, after Andromeda, not including the Milky Way's two satellite galaxies (the Large and Small Magellanic Clouds.)
NGC253 can be seen with binoculars with a long axis ~2/3 of the full moon with the right viewing conditions.
Milky Way and Zodiacal Light over Australian Pinnacles Image Credit & Copyright: Jingyi Zhang
ASTRONOMICAL EVENTS | SEPTEMBER
ZODIACAL LIGHT SEASON BEGINS by Matt Woods
The Zodiacal light season begins on September 1. As the Sun approaches the September Equinox on September 22, it causes the backscattering of light off of dust particles spread out along the ecliptic plane (the apparent path of the Sun’s motion on the celestial sphere as seen from Earth). Spring and Autumn are the best times to see this pearly glow in the sky at dawn or dusk, because of the steep angle of the ecliptic relative to our horizon. The September Equinox season favours dusk for the Southern Hemisphere and dawn for the Northern Hemisphere; the reverse is true near the March equinox. To best see the zodiacal light, go out around an hour after sunset or an hour before dawn. Look from as dark a site as possible because any light pollution or faint glow from distant cities on the horizon will destroy the ethereal glow. The zodiacal light will appear as a slender pyramid-shaped glow, tracing the length of the ecliptic plane.
Zodiacal Light. Image Credit & Copyright: Alan Dyer
The Perseids on 13/08/21 at 06:00. Image Credit: Stellarium
ASTRONOMICAL EVENTS | SEPTEMBER
SEPTEMBER EQUINOX by Matt Woods
On Thursday, September 23, the Southward Equinox occurs at 03:20 (AWST) marking the beginning of astronomical Autumn/Fall for the Northern Hemisphere and the start of Spring for the Southern Hemisphere. The Equinox is the exact moment when the Sun's declination equals 0, as seen from the Earth. The two points where the ecliptic or the imaginary path the Sun seem to trace out along the celestial sphere meets the celestial equator are known as the "equinoctial points." In the 21st century, the September Equinox last fell on September 22 in 2016 and will fall on September 22 or the 23 until 2092, when it begins falling on September 21 every four years. The equinox (literally meaning 'equal nights' in Latin) indicates that night and day are nearly equal worldwide and that the Sun rises due east of an observer on the equinox and sets due west. The Full Moon nearest to the September Equinox is known as the Harvest Moon, a time when farmers use the extra illumination at dusk to bring in crops. In 2021, the Harvest Moon falls on September 21. The term Equilux sometimes discerns the difference between the true equinox and the point when sunlight length equals the length of the night. Several factors play a role in this, including the time it takes the physical diameter of the Sun to clear the horizon, atmospheric refraction, and the observer's true position in their respective time zones. The Equilux occurs within a few days of either equinox.
The Perseids on 13/08/21 at 06:00. Image Credit: Stellarium
SEPTEMBER
VIRTUAL STAR PARTIES hosted by Matt Woods
Tune in this August as the amazing Matt Woods presents a livestream from one of our telescopes, showing off our amazing Southern sky. Join us! The virtual start party starts at 20:00 (AWST). Click the links below and sign up.
The Wizard Nebula Image Credit & Copyright: Andrew Klinger
Perth Observatory's Virtual Star Party
Wednesday, 4 September 2021 Register here - free!
Moon over Andromeda Composite Image Credit & Copyright: Adam Block and Tim Puckett
Perth Observatory's Virtual Star Party
Wednesday, 25 September 2021 Register here - free!
PAPER-BASED
RECORDS PRESERVATION by Carol Wolf, librarian and archivist Our aim is preserving the historic paper based files of the Perth Observatory.
Since its establishment in 1896, Perth Observatory has served the needs of the early Swan River colony and then the State Government of WA in matters of astronomy and associated scientific fields. During its 120 years of existence, many of WA's State Government departments have governed the observatory. During this time, for reasons including the observatory's remoteness from various administrative offices, a lack of information technology integration between administration offices and the observatory, and a poor understanding of the observatory's core business, very few of the departments integrated the observatory's records into their Records Management Systems. Almost all of the paper-based files generated during the observatory's operation are still here. Since 1896, Perth Observatory has worked collaboratively with international institutions in global astronomical research programs and made several significant discoveries, including discovering Uranus' ring system. The records include details of astronomical research programs and measurements and records of scientific research in the related fields of time-keeping, early meteorology and surveying, seismology and tide measurements, and communications around collaborations with other worldwide institutions. The files represent a communication media that has changed significantly since the nineteenth century and provide a unique perspective into the evolution of recording methods, literary style and communication mechanisms by the colony and state. The paper-based files stand alone in their contribution to detailing over 120 years of scientific research led by seven Government Astronomers and Directors, including William Ernest Cooke, the first Western Australian Government Astronomer.
The paper-based records also provide a unique insight into the cultural history of the Observatory and the nuances of a Colony, State and organisation whose staff arrived from across the globe and stamped their signature onto Western Australian history.
The records also tell us how two World Wars and a Depression affected Australian science and a European post-World War II Australian migration policy that contributed to Australia's scientific growth on an international stage. The Perth Observatory buildings, telescopes, historical artefacts and records were recognised in 2005 by entry onto the WA State Heritage Register.
Preserving nearly a century and a half's paper-based records
In 2017, Lotteries West funded a Significance Assessment for the heritage collection at Perth Observatory. The assessment found that the artefacts and paper-based records at the Observatory are of international significance and provide extensive evidence of numerous global scientific, colonial and state functions.
Project Commencement
Perth Observatory Volunteer Group took over the observatory's management in 2015. At the time, most of the paper-based records were stored in non-acid-free boxes without most archival or preservation considerations and stored in a former photographic room that still contained active water sinks, chemicals and cleaning products. Others lived in an old wooden cupboard in the dusty Publications Room downstairs. The POVG Heritage Sub-Committee took immediate action by relocating most paper-based records to a safer environment in the POVG Historian's Office. As of 2017, 500 files have been relocated to more secure storage and catalogued in a library system by POVG volunteers. At the time, most records were stored in metal filing cabinets in non-acid-free folders, and pest control measures and the operation of an old air conditioning unit provided some protection. In addition, approximately 500 files that hadn't been collated, recorded or placed in appropriate storage boxes sat uncatalogued and loose on tables in the Historian's Office. This storage arrangement for the paper-based records was hugely inadequate and did not conform to Australian preservation standards. The Historian's office was not fully air-conditioned or protected from UV rays as the air conditioner and blinds were over 50 years old and needed replacement. In addition, there was no temperature or humidity monitoring system and no NLA-approved shelving or archive boxes available for storage.
These records detail a 120-year history of astronomy and associated sciences in WA and contain the longest standing Government-funded astronomical institution in Australia.
PERTH OBSERVATORY'S
FAIRY DOORS
Scattered around the grounds of Perth Observatory are six special fairy doors, hand-crafted by Perth Observatory volunteers. We recently hosted a magical afternoon Fairy Tea Party, celebrating the release of the children's book ‘Out and about with Artemis at the Perth Observatory’ by Dr Janet Baldwin. If you haven’t yet seen the fairy doors, or would just like to see the magical doors again, please come explore the Observatory and find them all. We’re open Monday to Friday, 10:00 to 16:30, and on Sundays from 13:00 to 16:00, as well as for scheduled night tours and special events ‘Out and about with Artemis at the Perth Observatory’ is written by Perth Observatory secretary Dr Janet Baldwin and lovingly illustrated by Sharon Tapscott.
Pick up a copy of the book for $7.95 in the Perth Observatory Astroshop. Artemis will help you find all of the various Fairy Doors, plus there's interesting facts about the planets and constellations to learn, too.
CONTAINERS FOR CHANGE by Julie Matthews Help Perth Observatory through the Containers for Change scheme. Please take glass, plastic, aluminium, steel and paper-based cartons between 150mL and 3L to your local Containers for Change refund depot, and use scheme ID C10424615. Perth Observatory receives 10 cents for each container. Save the ID on your phone for every time you recycle your containers. Find your local refund depot and get more info on what containers are eligible for refunds, click here: containersforchange.com.au/wa Can't get to a refund centre? We have a dedicated and labelled bin on-site for you to add your clean container donations when you next visit the observatory. Our maintenance and accounts volunteer, Des, collects donated containers and takes them to the refund centre.
When returning your containers use our scheme ID
Thank you for helping the POVG promote sustainable and environmentally conscious practices and diversifying ways for us to raise much-needed funds.
C10424615
Your help supports the continuing upkeep and running of Western Australia's oldest observatory!
Eligible Containers Most glass, plastic, aluminium, steel and paper-based cartons between 150 ml and 3 litres are eligible.
Image credit: xkcd https://xkcd.com/2469/
Contact Us Perth Observatory PO Box 179 Kalamunda WA 6926 (08) 9293 8255 newsletter@povg.org www.perthobservatory.com.au Support Us Click here and support Perth Observatory on Patreon
Perth Observatory Volunteer Group acknowledges the traditional custodians of the lands on which we operate, the Wadjak clan of the Noongar Nation, whose land extends to the present-day site of the observatory. We recognise their continuing connection to these lands, waters and communities, and are grateful for the scientific contributions made by the world's first astronomers.