Aligned & Focused for the James Webb Space Telescope NASA’s next generation space telescope is about to be unleashed on the universe
Taking A Photo Of The Impossible Learn how the Event Horizon Collobration took the first image of our Galaxy’s supermassive black hole
Is Project Hail Mary A Must Read? Our Julie Matthews review the latest book from author Andy Weir
How To Buy A Telescope Looking to buy a telescope? We’ll let you know what to need
JULY 2022
NEWSLETTER
- Nikita Gill, poet and writer
Image Credit & Copyri: M.Taha Ghouchkanlu
We have calcium in our bones, iron in our veins, carbon in our souls, and nitrogen in our brains. 93 percent stardust, with souls made of flames, we are all just stars that have people names.
Contents
05
A View Through The Eyepiece
07
Upcoming Events
08
Staff Updated
09
Aligned & Focused
13
Taking A Photo Of The Impossible
20
Getting In Touch With Our History
23
Keeping Up With The Volunteers
25
How To Buy A Telescope
Find Us Here
31
Star Adoption
32
Project Hail Mary Review
33
What’s In July’s Skies
37
What’s In August’s Skies
40
Sunday Day Tours
41
What’s In September’s Skies
45
A Quick Look In The Shop
49
Obi Wan Cannoli’s
Editorial
Contributors
Subscriptions
Front Cover Image By
Zoé Fraussen Editor
Michelle Ashley-Emile, Jodie Sims, Matt Woods, Neil Francis, Julie Matthews, Zoé Fraussen
Click Below to subscribe to our newsletter
Matt Woods
Matt Woods Designer
Back Cover Image By Roger Groom
PAGE 05 2022 WINTER EDITION
A View Through The Eyepiece Kaya and Welcome Perth Observatory Volunteer Group acknowledges we operate on the traditional lands of the Whadjuk-Noongar people. It’s getting cold as we are heading out of the season Djeran and into Makuru so don’t forget your jumpers if you make your way up the hill. The much-needed rain certainly adds a great atmosphere and makes the bush look even more beautiful, but don’t be alarmed if there’s rain on your night sky tour. We may not be able to show you the stars when it rains but we can show off some of our amazing historical telescopes and give you some insight into the amazing astronomical work that has been done at the observatory over the years. As excited as we are by all the rain, we are even more excited to announce that we have received a grant from the Department of Jobs, Tourism, Science and Innovation. This grant will allow us to broaden our STEM outreach programs, collaborate more with other scientific organisations, create new school programs, and much more over the next four years. We are very thankful to JTSI and can’t wait to see what comes next. In this edition of our newsletter, you will find Part 2 of our discussion of the James Webb Space Telescope and find out what it’s been up to in the last few months. If you ever thought of buying yourself a telescope our beginners guide is just for you and can help you pick the right ‘scope for your needs. One of our volunteers has also just published a short book on the history of the Government Astronomers and Directors of Perth Observatory ranging from 1896 to 2013. If you are interested in history, astronomy, or just want to help support us you can now purchase this book in our AstroShop. It’s a great way to connect with local history and learn about some of the amazing ways Perth has contributed to global astronomy. We are continuing to grow here at the Perth Observatory, and we hope you will join us on our journey to share our passion and love of space and astronomy. Through volunteering, coming along to a tour, following us on social media, or just telling a friend about Perth Observatory you can be a part of this special group of space nerds. We welcome all. POVG pay our respects to Noongar Elders past, present, and emerging.
Zoé Fraussen Editor
PAGE 06
2022 WINTER EDITION
The Helix Nebula
NGC 7293
Lunar Photography Workshop Time: 7 to 10 pm Price: $120 per person This promises to be a fun relaxed evening of photographing the Moon on some fantastic telescopes using your camera. Using a combination of Astrophotography Australia telescope and equipment, and the Perth Observatory telescopes, we will have a wide range of focal lengths (magnifications) and types of telescopes available. You will be able to take photographs of the moon that feature the full disk, and photographs that are at much higher magnification.
Image Credit: Roger Groom
2022 WINTER EDITION
11th of August
24th of September Wallal Expediation 100th Anniversay Talk
Image Credit: WA State Library
PAGE 07
Upcoming Events
Come celebrate the 100th Anniversary of the Wallal Expedition with us. Our Arthur Harvey will regale you with story about how The Expedition which Perth Observatory was a part of, helped prove Albert Einstein’s Theory of General Relativity. Check our website and social media closer to the date for more details and to book.
Perth Observatory Volunteer Group has always depended on its volunteers for the running of day-to-day operations. This meant that a few people were doing an extraordinary number of hours and holding down multiple positions just to keep the “back side” of the Observatory running. In May this year we were lucky to receive the funding from the grant awarded us in 2020 from the Western Australian Government through the Department of Jobs, Tourism, Science and Innovation (JTSI) which has allowed us to employ some key staff members for the next 4 years. The positions were filled from our volunteer database, and we would like to congratulate the following people in their roles and thank them for the countless volunteer hours they have given us in the past:
Program Manager - Paul Wadham
STEM Outreach Officer - Zoé Fraussen
Business Support Officer – Jodie Sims
Volunteer Engagement Officer – Nadia Cooke
The Perth Observatory Volunteer Group’s STEM education and engagement programs are supported by the Western Australian Government through the Department of Jobs, Tourism, Science and Innovation.
Image Credit: Julie Matthews
We are very grateful for this government assistance; it will allow our valuable POVG volunteers to continue to develop and run a variety of programs that will hopefully provide future income and resources for our beloved Observatory.
2022 WINTER EDITION
by Julie Matthews
PAGE 08
Staff Update
PAGE 09
Aligned &
2022 WINTER EDITION
JWST progresses ever closer towar
By Jodi
We are one step closer to unravelling the mysteries of the universe with the James Webb Space Telescopes’ penultimate phase of commissioning completed. The multi-phase commissioning process for this freshly launched galactic eye in the sky officially started the second of blast off from the launch pad of the Kourou space port in French Guiana on Christmas day 2021. The first phase of spacecraft launch and deployment ran smoothly with no reported issues during the unfurling process. The tennis court sized sun shield was unfolded over a period of a week bringing the final steps of the deployment to a close on January 8th. The next crucial phase was to cool down the onboard instruments ready for mirror and scientific instrument commissioning operations to begin. This phase saw the Gaseous Helium Cryocooler chill down the science instruments to -266◦C, a temperature below the freezing point of nitrogen. This incredibly low temperature will help optimise the detection of the faint heat signatures from infrared light with limited interference from onboard generated electronic heat. Astonishingly according to NASA the JWST is so sensitive to infrared light, it would be able to detect even the slightest heat of a bumblebee at the distance of the moon. Surprisingly the 18 hexagonal gold coated beryllium mirrors stretching 6.5 meters in diameter took a while longer than the instruments to cool down. This was mostly due to the fact beryllium has a long thermal time constant at cryogenic temperatures, meaning this particular material takes a long time to cool down and heat up. The operational target temperature for the mirrors is below - 223◦C. By February the telescope was optimally cooled and the 3 month, 7 stage instrument and mirror alignment process could begin. This has been the most exciting instalment in the JWST story so far.
Image Credit: NASA GSFC/CIL/Adriana Manrique Gutierrez
PAGE 10
& Focused
ie Sims
Stage 1 was known as ‘Segment Image Identification’ and this stage resulted in NASA releasing the very first JWST image on February 11th , showing an array image comprised of 18 images of the same star. The lucky star chosen for this monumental step is know as HD 84406 , a sun like star situated 260 light years away in the constellation Ursa Major. This first fuzzy image mosaic was taken over 25 hours beginning on the Feb 2nd the telescope was pointed at 156 different positions around the location of the star generating 1,560 images in total using the NIRCam. The results of this imaging session validated that all 18 mirrors were working and had survived the journey thus far. The next four phases were know as ‘Segment Alignment’, ‘Image Stacking’, ‘Course Phasing’ and ‘Fine Phasing’. These phases would allow NASA’s engineers to make the fine focus corrections to both primary and secondary mirrors required to bring the 18 fuzzy dots of light into sharply focused star dots that could be image stacked to form one crisp image. On March 11th after many weeks of primary mirror alignment the NASA team finished focusing the JWST. On the March 16th an image of 2MASS J17554042+6551277, was released. This star was chosen for its remoteness away from other stars so it could be easily identifiable. Excitingly, when the team imaged the star with the Near Infrared Camera not only did it image the focused target star it also picked up some background galaxies. This star is around 2,000 light- years away in the constellation Draco within our Milky Way Galaxy. However the background galaxies are estimated to be billions of lightyears beyond. “We now have achieved what’s called ‘diffraction limited alignment’ of the telescope,” said Marshall Perrin, deputy project scientist for Webb at the Space Telescope Science Institute. “The mirrors are focused together as finely as the laws of physics allow, and this is the sharpest image you can get from a telescope of this size.”
2022 WINTER EDITION
rds cycle 1, its first year of science.
PAGE 11 2022 WINTER EDITION
The sixth phase known as Telescope Alignment Over Instrument Fields of View’ would see all scientific instruments calibrated. This phase looked at star fields as seen by NIRCam, NIRISS, FGS, and NIRSpec to see whether they were in focus. Optical error measurements were then taken by the engineering team to help with determining the final alignment corrections required as part of the final seventh stage of alignment. On April 28th NASA announced that the JWST can now capture sharp images of celestial objects with multiple instruments and released an image showing off it’s repertoire from all four of its science instruments exceeding all expectations for image quality. This was followed by NASA releasing a stunning comparison image showing the same image taken by the JWST vs the now retired Spitzer on May 9th. The image taken by the MIRI, the Mid-Infrared Instrument, Webb’s coldest camera shows part of the Large Magellanic Cloud, a small satellite galaxy of the Milky Way next to the same image taken by the Spitzer Space Telescope. It really shows how incredibly clear and sharply focused the JWST is in comparison. Now that the JWST optics and instruments are aligned the project is entering its final overall stage of commissioning before the start of its first main science operations starting later this year. This final stage is know as science instrument commissioning and will take approximately two months to complete. There is a suite of 17 different scientific instrument modes to commission across the 4 parent instruments. Once these are checked off and ready, scientific operations and discovery can begin. Each of the 17 modes are designed with specific analysis in mind. These modes will be selected by the scientists across the globe to best suit their selected fields of particular research. There was fierce competition for securing observing time during cycle 1, the first year of science with over 1,000 proposals submitted before the deadline back in November 2020. Scientists from 44 countries applied for a portion of the 6,000 general observing hours available in this first year. This equated to two thirds of the overall time, with the rest allocated to the Early Release Science Program and Guaranteed Time (GTO) programmes set by the Scientists that worked on developing JWST hardware and software components. Future programs cover all areas of astronomy from examining chemistry in planet forming regions, analysing galaxy protocultures and drivers of cosmic reionisation to examining the physics behind black hole jets. NASA is scheduled to release the first images taken by the Telescope on July 12, I predict a wave of exciting new celestial discoveries, expanding upon previous knowledge of the cosmos and perhaps challenging the current known rules of astrophysics.
Image Credit: Andras Gaspar
2022 WINTER EDITION
New image of the Large Magellanic Cloud. Image Credit: NASA/ESA/CSA/STSScI
PAGE 12
PAGE 13 2022 WINTER EDITION
Taking A Photo Of The Impossible We finally get to see our galaxy’s black hole By Matt Woods
On the 12th of May, humans finally got to see Sagittarius A*, the supermassive black hole that sits at the core of our galaxy, the Milky Way. The image was created from data that was collected by the Event Horizon Telescope Collaboration. In 2019, this ground-breaking collaboration released the historic first image of a black hole, that of the supermassive black hole at the centre of the Galaxy M87. Up until now, we were fairly sure that our Galaxy also had a supermassive black hole at its centre, but we were missing the proof. While some theories over the past years suggested we did not, this stunning image finally proves that we do. This image shows us the accretion disk around our black hole, a disk-like flow of ionised gas, dust, and stellar debris that orbits the black hole, not quite falling in. We can see this disk because the immense force of the black hole’s gravity accelerates the spinning particles, and they smash into each other releasing X-rays and gamma rays. We can also see the event horizon, the inner hole of the doughnut which is the threshold where to escape the pull of the black hole, you would need to move faster than the speed of light. The ring shape in the image comes from the gravity around the black hole bending the light from the accretion disk behind the black hole so that we can see it. The image is actually a monochromatic image, the team uses orange to add colour to the image, so it is easier to see the details in the image. The three bright nodules are clumps of dust and gas. The top right one is brighter due to the doppler effect.
2022 WINTER EDITION
The first image of Sag A*. Image Credit: EHT Collaboration
PAGE 14
2022 WINTER EDITION
Infrared shot of the centre of our galaxy. Image Credits: NASA, ESA, SSC, CXC, STScI
PAGE 15
You must be thinking this is an extremely big telescope and it must collect a lot of data, and you would be right, they do not just collect gigabytes or terabytes of data, they collected petabytes. They collect so much data they cannot send it via the Internet, they must fly these hard drives to and from the observatories and the supercomputer that crunches the numbers and creates the simulations based off that data. Now by this stage, you are probably thinking why the need for such a large telescope, are these astronomers working for Dr Evil? Well, the good news is, that they are not working for Dr Evil. This collaboration is funded by the United States National Science Foundation. The reason we need such a large telescope to see our black hole is that it is extremely hard to see it. Firstly, black holes are by their very nature black. Nothing, not even light can escape their gravity. We also live in the middle of our Galaxy, and our view of the galactic centre is hidden to us in the visible spectrum of light by the dust in the Sagittarius arm of our Galaxy. It is as if we are looking at it with
Simulations and years of observations in other light waves including in x-ray and radio have made it possible to partially mitigate the effects of this blurring. As supermassive black holes go, Sagittarius A* is not the most massive, it is quite a common-size black hole. Do not expect it to be going into the cosmic nightclubs and making it rain with money, this is a working-class black hole. Its mass is over four million times the mass of our Sun, and the event horizon is about twelve million kilometres across, that is thirty times the Earth-Moon distance. If we tried to look at it from another galaxy, we could not detective it with today’s current technology. The reason we can detect it at all is that it is only 26,000 light-years away from us. What the Event Horizon Telescope team did was the equivalent of seeing a doughnut on the Moon from Earth.
2022 WINTER EDITION
It is possible to combine observations from radio telescopes that are separated on Earth by a certain distance, that way it makes them equivalent to a telescope the size of their separation. This is a technique known as Very Long Base Interferometry, and this is the method that the Square Kilometre Array which is being built in South Africa and Western Australia will use as well. The Event Horizon Telescope has observatories across the world from Greenland to Antarctica, from Europe to Hawai’i and together, they function as a telescope as big as the Earth.
frosted glasses. We need to use other parts of the light spectrum to unveil the galactical curtain to see what is behind it, and therefore the collaboration used radio waves.
PAGE 16
Now this intergalactic doughnut might seem cool, but what makes it stunning is the story of how they were able to create this image and what this image tells us about our supermassive black hole. To reach that incredible resolution, you need an enormous telescope, or you need to be very clever with physics. The Event Horizon Telescope collaboration did the latter to create the image.
These observations have greatly improved our understanding of what happens at the very centre of our galaxy. It offers new insights into how these giant black holes interact with their surroundings. The scientists were stunned by how well the size of the ring agreed with predictions from Einstein’s Theory of General Relativity. The size of the shadow of the singularity is not precisely known just yet. This is because the scientists do not know if the black hole itself is spinning. The simulations suggest it spinning, but to what rate, the scientists are not too sure yet, and that spin can have a small effect on the diameter. Sagittarius A* also matches the predictions made by studies that looked at the motions of stars orbiting Sagittarius A* as well. Because Sagittarius A* is 1,600 times smaller than M87*, the scientists needed to capture their data quickly as the environment around it changes more quickly, which made creating the image much more challenging. The scientists had to be careful of blurry images as the innermost stable orbit for Sagittarius A* is about 4.5 light-minutes
PAGE 17 2022 WINTER EDITION
instead of weeks like M87*. The M87* image is the size of the solar system and is gorging on dust and gas which shoots out jets of material from its poles that extend as far as the edge of its galaxy. The Sagittarius A* image is the size of mercury and is not shooting jets as it doesn’t have a lot of dust and gas around it like M87*, only every so often a cloud of dust or gas gets too close, and it gets to feed. If Sagittarius A* was a human, it would eat a piece of rice every million years, that is one hell of a diet. While some Black holes can be very efficient in converting gravitational energy into light, Sagittarius A* traps nearly all the energy it captures (one part in a one thousand is converted into light) so it is ravenous by inefficient. It is only putting out a few hundred times as much energy as the Sun, but it is four million times as massive. Other discoveries the scientists found, were that we see Sagittarius A* face on, so the black hole is not aligned to the galaxy, its slightly tilted towards us. Sagittarius A* has a strong magnetic field to the gas around the black hole but it is weaker than the fridge magnets on your fridge, but everything is relative. They also found the accretion disk is trillions of degrees kelvin. The Event Horizon Telescope team is not just stopping there. They have been conducting observing campaigns throughout the pandemic in 2021 and 2022 with even more telescopes, expanding their observations to other objects. The first issue they needed to deal with is the scattering of radio waves by the Sag arm of the galaxy. The scientists are already starting to push their equipment to look in the 345 gigahertz range. This will cut the scattering in half and produce sharper images. With support from the Nation Science Foundation and other partners, they are also designing next-gen equipment and adding new telescopes to the Event Horizon Collaboration. This way they can go beyond still images and reveal the first-ever footage of a changing supermassive black hole. So, make sure you’re strapped in as we are only at the beginning of this amazing journey.
2022 WINTER EDITION
ALMA looking up at the Milky Way. Image Credits: D. Kordan/ESO
PAGE 18
PAGE 19
2022 WINTER EDITION
PAGE 20 2022 WINTER EDITION
Getting In Touch With Our History By Zoé Fraussen
In 1896, after hiding the funding for a new Perth Observatory in the plan for the Perth Mint, Sir John Forrest invited William E. Cooke to become the first Government Astronomer of the Perth Observatory. This was the beginning of Cooke’s illustrious career at the Observatory. During his 16 years as Government Astronomer, Cooke worked as an astronomer, surveyor, meteorologist, seismologist, educator, journalist, and more. He was also a prolific inventor and has been credited with around 100 different patents. This is where our story begins. POVG Heritage volunteer Robin House was tasked with trying to find the supposed over 100 patents that Cooke made. This seemingly innocuous task would end up taking Robin on a journey through Perth, Canberra, and the British Library, through patents for curtain rods and car hookers, and end up bringing descendants and artifacts together across Australia. The only patent on record for W. E. Cooke was for an improvement of the astronomical
clock, but sources had cited him with over 100 inventions and patents. Finding out that Perth didn’t hold patent records Robin contacted the Canberra Department to see if they had any luck. With helpful and enthusiastic staff also becoming interested in her research Robin was passed from contact to contact attempting to find the information she wanted. The British Library ended up having the biggest hit of W. E. Cooke patents sending Robin 19 pages of inventions. Unfortunately, as Robin was to discover, W. E. Cooke was not a very rare name and most of these patents were not the Government Astronomer we were looking for. After a long search, a contact in Canberra came back with 4 patents given to the correct W. E. Cooke for the correct dates, but unfortunately, they were duplicates of the original patent for different countries. Another dead end. It seemed as though there would only ever be one patent found for Cooke. However, we do know that Cooke was a great inventor, but we may have to
2022 WINTER EDITION
Along the way, while Robin had no luck with finding the patents, she did find something arguably better. Robin got in contact with Cooke’s relatives and through their generosity was offered a collection of artifacts, notes, and letters from Cooke to add to the Perth Observatory collection. Chief among these are the original Cooke Sunclock and a portrait of W. E. Cooke done by his grandson, 3-time Archibald prize winner, Clifton Pugh. These beautiful artifacts will be on display in the Observatory Museum. To finish off this remarkable journey the Observatory held a W. E. Cooke morning tea on Tuesday 14th of June. In attendance was Deb Wild, a granddaughter of Cooke who traveled from Sydney, and Gwen Digby, whose late husband was Cooke’s grandson, who video called in from Brisbane. The morning tea was a lovely event, with talks from Robin about her journey, a look into the life of W. E. Cooke and his accomplishments from Dr Craig Bowers, and a tour of our museum, newly filled with a Cooke-based exhibition featuring the new donations from the Cooke family. It was amazing to see how one man and his passion for the observatory, education, and his family led to the Observatory we know and love today. Banner Image Credit: Matt Woods
Sir William Ernest Cooke. Image Credits: Perth Observatory
PAGE 21
deduced that he was just not a good patent filer.
PAGE 22
Pick your favourite planet in our AstroShop and take them home today!
2022 WINTER EDITION
The planets have arrived!!!
PAGE 23
Keeping Up With The Volunteers By Julie Matthews
2022 WINTER EDITION
National Volunteer Week 16 - 22 May 2022
Our event was a casual dinner in the barbecue area combined with a night of fun games. It was a great opportunity for volunteers from the different areas of the Perth Observatory to meet each other and take part in team activities. We were delighted to see our volunteers broaden their friendship base and have a good laugh as they worked together. Our yummy meal was from Lesmurdie Club, we had an “icecream station” for dessert and Zoé Fraussen was our hilarious MC for the night. We hope you enjoy some of the photos from our night.
Nola Edjar. Image Credits: Julie Matthews
Thanks to LotteryWest and Volunteering WA we received a grant to show our wonderful volunteers how much we appreciate them on Monday 16 May during National Volunteer Week.
It is such a joy to be involved with an organisation that allows us to share our knowledge and our passion for cosmology with school children of various ages. As they learn about the vastness, diversity and wonders of the Universe, we hope the students will come to appreciate Earth’s unique place in the cosmos and inspire them to become passionate about protecting our planet. We are always excited when Nola and Jack are in for a tour. As well as being a fun and informative presenter, Nola is an amazing cook – her home-made lamingtons are out of this world! Both Nola and Jack also help with the updating of activities and are are always happy to lend a hand where needed. So, if you are enthusiastic, enjoy communicating with children and are available during school hours, click below. All training is provided!
Banner Image Credit: Julie Matthews
So, you’ve got a sore throat. This is what you need to do: Before bed, take a long sock that you have worn all day – wool is best, and the longer you have worn it the better, a couple of weeks is good. Wrap the sock around your neck, take a couple of sips of scotch and go to sleep. When you wake up, your sore throat will be better. Thanks Kenny – we are all glad that your remedy works so well for you, and of course now we understand the source of the smell….
Rob Kennedy (Left) and Ken Day (Right). Image Credits: Julie Matthews
Around 2012, Jack and I became part of the Perth Observatory Volunteers Group when we joined the dedicated team of Night Tour presenters. For the past few years, we have been members of the School Day Tours Team. Neither of us had any experience in the astronomy field but Jack is a born organiser, and I developed a fascination for all things astronomical from a very young age. A fascination that has never waned.
You may have noticed that there is a lot of socialising going on at Perth Observatory whilst we work away. During Morning Tea, Lunch Break, and before and after Tours the kitchen is humming whilst volunteers of all ages and walks of life share some interesting stories over a hot drink and bikkies. Since the weather is so cold at the moment and many have sore throats, I thought I’d share a handy hint passed down to Wednesday Maintenance Crew member Kenny Day from his old Dad. (Kenny has a strong east Midlands English Accent).
2022 WINTER EDITION
Do you have free time during school hours? We urgently need volunteers for School Day Tours. Presenter Nola Edgar, talks about her time with the School Day Tours Team:
Handy Hints From The Tea Break Goss
PAGE 24
The Next Intake
PAGE 25 2022 WINTER EDITION
How to buy a telescope By Neil Francis
So you’ve visited Perth Observatory, and experienced a small taste of what there is to see in our marvellous southern skies, and you’ve decided to buy a telescope. We’re excited for you, because you’re going to discover a whole new world! But there seem to be many options, so where do you start? You may already have looked on the internet, and found the many technical details to get lost in. We hope that this guide will help you decide what’s best for you and how you may want to use your telescope, without too much technical nitty-gritty. The first question is, what’s important to you? Are you a small person who needs a telescope that can safely be carried up and down stairs? Do you have children too impatient to give you ten minutes to locate a nebula? Or is a slower astronomy experience more your style, where half the fun is the thrill of the chase, skilfully hunting down galaxies and other faint fuzzies? Do you have a dedicated observing location that is fortunate to see dark skies? Or do you need to transport it in a car? Where will you store it? What is your budget? How interested are you in astronomy? Have a think about these things because they’re as important as any of the technical matters. We’ll come back to them later in the article. A good telescope is one that you’ll use, and not necessarily the biggest or best. We hope that your experience at the observatory has given you realistic expectations about what can be seen with a telescope. You’ve seen the bright colourful photos from the Hubble Space Telescope countless times in magazines, on TV and on the internet. Amazing images like these are approachable through a modern backyard astrophotography set up, but this is a bad place to start for a beginner as a lot of time,
money and experience goes into creating photos like that. We’ll focus on what’s seen through an eyepiece for this article, as photography is an advanced topic, and the best telescopes for eyepiece viewing are not best for photography. Most objects that can be seen by eye are very faint, and our eyes aren’t good at perceiving colour in faint objects. This means that much of the universe you see through the telescope will lack the intense colours you see in the photos. Don’t let this discourage you from buying a telescope. We think there’s magic in seeing a galaxy 50 million light years away with your very own eyes. M87 is this far away, home of the first black hole that professional astronomers have directly imaged, and currently in our early winter sky, in Virgo. The light that left that galaxy not long after dinosaurs roamed the earth has travelled for 50 million years just to touch and be absorbed by your eyeball so that you can experience it! In a sense, you’ve actually touched the billions of stars in that galaxy! And this is something that you can experience with a modest telescope. We think that much of the wonder that comes from a telescope comes from knowing what it is that you’re looking at, and not just the view in the eyepiece. That said, there are some sights best experienced through a telescope. You can see details with a backyard telescope that you may never have seen in the photos. How can this be? Well to create a photo that exposes nebulae well, in all of their glorious colour, it’s common to overexpose their bright details and so these are often lost in the photos. The Trapezium in The Great Nebula in Orion (M42) is an example of this. At the heart of M42 can be seen these four bright stars, even in the smallest of telescopes, and yet you rarely see these in the glossy photos. These
PAGE 26
details often missing are easily accessible from the backyard.
Okay, so now that we’ve managed our expectations, we’ve considered our answers to the questions above, how can this help us choose a telescope? Is it right for me to buy a telescope now? Astronomy with a telescope can be a rewarding experience with a good first telescope and a bit of knowledge. There are many cheap options available with claims of high magnifications, but a good entry level astronomical telescope with modest magnification will set you back at least $400 and either provide a capable instrument for casual use for many years, or provide a stepping stone to further acquisitions if your interest expands. Lesser equipment is likely
Mother and daughter observing stars. Image Credit: True Touch Lifestyle
The atmosphere also degrades the heavens through what astronomers call “seeing”. Our atmosphere is often turbulent and this makes views fuzzy in larger telescopes, or causes stars and planets to jump around or break up into strange shapes in small telescopes. This can change from day-to-day, and even by the hour, and is often worse on hot summer’s nights. Seeing means that there’s a practical upper limit to how much a telescope can magnify because trying to magnify more than seeing allows just brings us big fuzzy views instead of small fuzzy views.
2022 WINTER EDITION
Another matter of expectations is how your viewing will be handicapped by light pollution and the atmosphere. Here in Perth we often have very light polluted skies and this means that many of the fainter objects in the sky that would be obvious from the wheat belt are difficult for us to see, both by naked eye and even in the telescope. Planets, double stars, open clusters, and the brightest nebula and galaxies are easy to find from our backyard skies, but fainter objects need dark skies. If you’re able to transport your telescope away from Perth you’ll have a much better viewing experience (and the Astrotourism WA website will be able to help you find places to view the sky from our country towns).
PAGE 27 2022 WINTER EDITION
to show a very limited set of objects, have flimsy mounting that is frustrating to use and is more likely to be unsatisfying and deter your budding interest. Cheap telescopes are available, but as with much in life you really do get what you pay for. It’s best to stay away from small refractor telescopes for $100 at discount shops. These telescopes are likely to be poor quality, have shaky mounts and the shops are unlikely to offer good advice or after sales support. How interested in astronomy are you? Without spending much money, you could spend some time learning from others by joining a club or organisation of like-minded people. You can spend time researching topics through internet web searches, visit your mobile device app store for astronomy software, or pop by your local public library and borrow a book or two. You may like to get outside under the night sky with a “star wheel”, or “planisphere” ($10-$25), planetarium software for your mobile device ($0-$5 for entry level tools), or borrow a pair of binoculars or buy second hand (<$100). Binoculars can provide views of many of the brightest objects and many objects that can be seen during a night sky tour at Perth Observatory can at least be spotted in binoculars. Moderately sized binoculars like 10x50 and 8x40 are very portable, easy to use, and can easily be grabbed to look at objects and appreciate that the sky contains more than just stars. The first number refers to the magnification and the second to aperture in millimetres. They can be used for other activities like bird watching, in addition to looking at the sky. Learning to find your way around the sky with these inexpensive tools will make using a telescope more enjoyable. A telescope is a physical experience, quite unlike looking at images on the internet or watching a documentary. When you’re outside looking at the sky it may be quiet and cold, will hopefully be dark, and it can involve a surprising amount of movement, and sometimes awkward body positioning, as you seek objects out by eye, and direct a telescope to those objects. It’s often best enjoyed with a thermos and warm clothes,
and maybe even a tea break with cake! Do you enjoy being outside? Do you have the mobility to use the telescope you’re considering? Do you enjoy cake? Then a telescope could be the way to go. Don’t I just want a telescope that magnifies a lot? Surprisingly, no! Ignore telescopes advertised with a strong emphasis on magnification. Most objects that we look at in the sky don’t require magnifications above 200x. Unlike a microscope, the greatest value that a telescope brings is not magnification, but in light gathering. Telescopes make dim objects brighter, and this is often more important than magnification, also optics that collect lots of light provide more resolution. This is the difference between magnifying an object a lot and seeing a fuzzy image, vs seeing a sharp image. Any telescope can provide high magnification with the right eyepiece, but the more light that’s collected the better the image. Those adverts that scream high magnifications are being misleading by not emphasising what’s important, and are often associated with poor quality instruments. Four key aspects to a first telescope are:
Diameter (also called aperture) of the main lens or mirror – this determines how much light is gathered
Steadiness of the mounting – determines how steady images will be, and how frustrating it will be to get the telescope pointing at the object you want to see.
Sales and service support – you will need advice and service over time
Cost constraints – getting good ‘bang for your buck’
Image Credit: Roger Groom
It’s generally accepted that the best value for money telescopes for beginners, are medium aperture (6-8”, 150-200mm) ‘Dobsonian’ style telescopes. Their value attributes are:
They provide enough light gathering aperture to give good object views at modest magnifications for most object types.
They have a solid manually manipulated mounting that is easy to use
Their manual operation provides a great basis for learning the night sky and how to find and follow objects in it
$400-$600 shipping)
price
point
(excluding
The compromises made for these values are:
The size of the telescope and mount makes them larger than some will find ideal, especially if there is a frequent need to transport the telescopes The manual nature of the mount means object location and tracking at higher magnifications are more difficult than electronic automated ‘GoTo’ telescope mountings. Many telescopes now sold do include attachments for a mobile phone that, along with an appropriate app, can help with locating objects even with a fully manually operated mount.
If these compromises are strong considerations, then your first telescope is likely to be more expensive. ‘Collapsible Dobsonian’ telescopes that are slightly more compact for transport and with ‘GoTo’ capabilities are available but will increase cost to approximately $1500 and above.
Entry level telescopes will come with adequate 1.25” diameter eyepieces, however significant improvement can
Apart from ‘webcam’ planetary photography, Dobsonians have very limited astrophotography use. Narrow field ‘deep-sky’ astrophotography requires a solid, automated, tracking mount and will require a considerably higher budget to do this well. This is a topic in its own right and not considered a ‘first telescope’ consideration. The expensive ‘widefield’ refractors that are also sometimes used for astrophotography make poor telescopes for visual use, at their price point.
Buying local for advice and support is recommended for a first astronomical telescope, however Perth is not well serviced by retail shops that stock and service a wide range of astronomical equipment. Advice from astronomical groups and observatories should be sought on current suppliers and experiences. Do I need a computerised telescope that can find and track objects? All telescope designs can be purchased in versions that find and track objects for you, but a telescope that offers automated tracking can be twice the cost as one with the same diameter of main mirror. So there is a substantial premium in tracking vs a non-tracking telescope with the same light gathering ability and quality of images. An inexpensive option that is found on many telescopes sold today is a mobile phone holder. With this you can use your phone with appropriate software to help you push
2022 WINTER EDITION
be achieved with higher quality 1.25” or 2” eyepieces as a future upgrade, independent of the telescope and mount. Good eyepieces will be in the $100-$250 price range. Eyepieces together with the main lens or mirror of the telescope set the magnifications available to you on the telescope. The main lens or mirror is not changed, but a range of eyepieces can be used. As eyepieces are standard sizes they can be used not just with your first telescope, but with future telescopes you may buy.
PAGE 28
Our pick for a first telescope
PAGE 29 2022 WINTER EDITION
your telescope to point to the object that you’ve chosen to see. Your phone has orientation sensors so it can identify the direction and angle of your telescope to figure out what it is looking at, and help you find what you’re looking for. Small telescopes are sometimes offered on equatorial mounts. These mounts aim to follow the apparent motion of the stars through the sky. Less expensive equatorial mounts are often not solidly built and may be frustrating. They will also require alignment with a point in the sky called the south celestial pole, that all stars appear to rotate around. Instructions will be provided, but the process may be annoying when you regularly move the telescope. We prefer the larger diameter Dobsonians that have simple, yet stable, mounts, but require manual tracking. If your day job sees you sitting in front of a computer all day, then perhaps you might enjoy escaping from this to an instrument that’s free of motors and computers? There can be excitement in planning a night of viewing and then meticulously hunting down each of the objects, through the use of paper charts. Others may find this frustrating. Two situations that may favour computerised tracking telescopes are (a) when you want to show objects to an audience, and (b) if you have limited time for the hobby and want to get the most out of the limited time that you have for viewing, rather than searching for objects. Objects like planets may quickly move out of view, and this requires more enthusiasm for learning to track with your telescope than some may have. This may be especially the case with an audience and especially if they are young children. Manual handling considerations
and
transport
Many of us don’t have backyards or dark skies at home to observe from and this means you’ll need to take your telescope on road trips to get the best from it. As an apartment dweller without a backyard, up a flight of stairs, and who lives alone, I appreciate how important the physicality of a telescope is.
Pay attention to the mass of the telescope and mount that you’re considering, and the fact that telescopes are awkward loads that often have their centre of gravity well away from your body. If you are small then it can even be difficult to see where you are going while carrying one. Tall, strong people, without injury or disability can come to grief through distraction, and when handling a telescope that is too big for them. If you choose a big telescope that you can only just handle then the effort will discourage you from using it. A better choice may be a smaller aperture scope that is more manageable. Can you transport it in your car? A Dobsonian with a 10” aperture is about the limit that tall strong people can handle from the perspective of carrying on level ground, and that can also fit in the luggage and back seat sections of a small hatchback, leaving space for a passenger beside the driver. Smaller 6”-8” instruments are more manageable. Larger telescopes can be purchased that disassemble into smaller pieces and can be re-assembled at the viewing site, but these are much more expensive and the work required in transporting and setting them up may be frustrating for a beginner. Do you have space for a telescope? Consider how much space you will need, and whether or not you have it. A type of telescope called a catadioptric, or compound, telescope can offer larger magnifications in more compact sizes than Dobsonians. This may be desirable if you’re most interested in observing planets, which can benefit from higher magnifications when the seeing permits this, and space is an issue for you. There is a cost premium in choosing these designs, however. Binoculars can be a good first choice, if handling and space considerations are important to you. Dobsonians require a process called collimation to be do when they’re moved. It sounds much scarier than it is, and is a skill that can be quickly learnt, and only requires a few minutes to apply. Regular collimation will get the best views out of such a telescope. Compound telescopes, and refractor telescopes can be more grab-and-go in that they don’t require regular adjustments.
PAGE 30
In Conclusion
Good luck for your new adventure!
Stargazer looking through our Celestron 11” telescope at Ongerup. Image Credit: Matt Woods
While we can’t go past the value for money in manually tracked Dobsonians, they may not be the best for everyone. If you need to make compromises for ergonomics, manual handling, storage or patience reasons, know that any good quality instrument can provide a wealth of objects to see, and will provide better images than anything early astronomers like Galileo could have dreamed of owning. Often there are details to be seen, but we’re not observant enough to notice. Revisit objects regularly and you will notice more and more, and you will also become more aware of how views change with atmospheric seeing. Learning to see is an important skill that will be acquired with time and can be gained even on smaller aperture telescopes.
2022 WINTER EDITION
Above all, we recommend you set yourself up for success by going slowly and learning as much as you can before buying. Your first telescope acquisition should be one that gives many years of enjoyment, or be the start to a fascinating hobby that can take many paths as your interest grows.
PAGE 31 2022 WINTER EDITION
Star Adoption Tours Our star adoption program provides a unique gift and is a way to recognise a family member or friend through the adoption of a star. All available stars in the program are between the magnitudes -1 and 4.9 (visible to the naked eye) or 5.0 and 7.9 (visible in binoculars), all in the Southern Hemisphere. The individual star adoption package includes: A certificate (suitable for framing) with star name and coordinates, and the duration and purpose of the adoption. Private star viewing night for the recipient and 3 guests within 12 months that include several other seasonal objects and will be 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 time) Star charts and coordinates showing where the star is located in the night sky, as well as being shown how to use these at the star viewing night Please note: Perth Observatory’s Star Adoption program doesn’t offer international naming rights to the star as there are no internationally recognised naming rights to the stars. The program is run by the Perth Observatory Volunteer Group Inc, and the income goes towards the Observatory’s not for profit, public outreach program.
Image Credit: Matt Woods
PAGE 32
Project Hail Mary
2022 WINTER EDITION
Book Review
By Julie Matthews It was with great anticipation that I snuggled up with Project Hail Mary – the latest novel by Andy Weir – and it was worth the wait! The story revolves around a high school science teacher, Ryland Grace, who wakes up in spaceship light years from earth with no memory of how he got there. Then things start happening ….
Astronaut Ryan Gosling. Image Credit: Universal Pictures
Metro-Goldwyn-Mayer have purchased the film rights for the story. Drew Goddard, who adapted Weir’s debut, The Martian, into a film in 2015 starring Matt Damon, is slated to adapt the book into a film with …. Ryan Gosling to star …. sigh. Definitely something to look forward to.
The book is an excellent read and fits well with Weir’s previous novels. There’s a lot of maths and scientific experiments that made my eyes cross but don’t worry, they made sense and didn’t bog the story down. Of course, imagining actor Ryan Gosling as Grace may have helped a lot there! This is a rollicking read of discovery and survival with lots of edge of the seat excitement, humour and of course, surprises. It is so rare to find a stand-alone novel in this genre these days, so ‘Project Hail Mary’ wins a lot of points form me for that. If you are looking for a new book to sink your teeth into, I really recommend this one, especially if you imagine Ryan Gosling as the lead, that helps in a lot of situations.
Rating:
4.5/5
PAGE 33
What’s In July’s Skies By Matt Woods
2022 WINTER EDITION
Planets: Mercury will be viewable for the first few days of July, very low on the horizon in the constellation of Taurus (The Bull) before disappearing into the sun’s glare. It will return later in the month in the constellation Leo (The Lion) for the last three days low in the evening sky. Venus can be found low in the constellation of Taurus until the middle of the month, when it moves through the constellation of Orion (The Hunter) and into the constellation of Gemini (The Twins). Mars is viewable in the early morning, and it’ll move from the constellation of Pisces (The Fish) to the constellation of Aries (The Ram) at the beginning of the second week of July. Jupiter will be in the constellation of Cetus (The Sea Monster) throughout July, rising around Midnight. Saturn can still be found late in the evening throughout July in between the constellations of Capricornus (The Sea Goat) and Aquarius (The Water Bearer). Uranus is rising in the early morning in between the constellations of Aries and Taurus. At the very end of July, it will be awfully close to Mars. Neptune is just above Jupiter, close to the more northern than fish of the cancellation of Pisces. It’s rising before midnight throughout July.
All the planets in alignment on the 01/07/22 at 6:15 am (AWST)
The Delta Aquarids Meteor Shower:
The apparent radiant for the Delta Aquarids is in Delta Aquarids on the 29/07/22 at 3 am (AWST) the constellation of Aquarius, and it can be viewable from 08:00 pm (AWST) on the 28th, but it’ll be best to wait until around 03:00 am on the 29th. The source of the Delta Aquariids is believed to be 96P/Machholz 1 comet which was part of the unnamed ancient stream of Kreutz Sungrazing comets
Celestial Wonder To Look At This Month: The star DY Crucis: The star DY Crucis is a carbon star very close to Mimosa (Beta Crucis) and is 4,077 light-years away from Earth. A carbon star is a giant star in a late phase of evolution. It’s similar to a red giant, but its atmosphere contains more carbon than oxygen. They tend to be variable stars, increasing and decreasing their size and variability over time. DY Crucis colour is a striking cherry red colour due to the carbon which reflects and scatters blue light, but The DY Crucis on the 15/07/22 at 9 pm (AWST) allows red light to filter through, like what happens at sunset. It’s surface temperature also plays a role, DY Crucis’s surface temperature is below 3,500 Kelvin, so it’s a cool star and would appear a shade of red. To put this in context, the temperature of our Sun is about 5,778 Kelvin.
2022 WINTER EDITION
The Delta Aquarids meteor shower are due to peak on the night of the 28th/29th of July and they’ll favour southern hemisphere observers, which includes observers in Perth. The shower is active from the 12th of July to the 23rd of August, and they can vary in their hourly rate each year between 10 to 20 meteors per hour. In 2022, we have a New Moon, so we won’t have to deal with any light pollution from it.
PAGE 34
Astronomical Events:
2022 WINTER EDITION
Image Credit: Sebastion on Astrobin
PAGE 35
DY Crucis A Carbon Star
PAGE 36 2022 WINTER EDITION
Join our School Day Tours Team Do you Have free time during the day? Enjoy talking with primary school aged children? Enjoy learning about Space and our Solar System and sharing what you learn? Then we need YOU in our School Day Tours Team! All training is provided! You just need enthusiasm, be able to communicate with children and be available during school hours.
Find out more by clicking below
Image Credits: Matt Woods
PAGE 37
What’s In August’s Skies By Matt Woods
2022 WINTER EDITION
Planets: Mercury can be found throughout August low in the West in the early evening. It’ll move from the constellation Leo (The Lion) into the constellation of Virgo (The Virgin) during the second half of the month. On the 28th of August, it will reach its greatest elongation in the West and start its journey back towards the Sun’s glare. Venus is low in the northeast in the early morning it will be moving from the constellation of Gemini (The Twins) to the constellation of cancer during the second week of the month, before it moves into the constellation of Leo. Mars rises in the morning sky in the Northeast. It’ll move from the constellation of Aries (The Ram) into the constellation of Taurus (The Bull) during the second week of August. Jupiter can be found again this month in the constellation of Cetus (The Sea Monster) and will be visible in the late evening in the east. Saturn is in the evening sky in the constellation of Capricornus (The Sea-Goat). On the 15th of August at 01:00 am (AWST), Saturn will reach its opposition and will be at its best viewing for us. Uranus is remarkably close to Mars in the eastern morning sky between the constellations of Aries and Taurus. On the 2nd and 3rd of August, they will be at the closest points to each other before continuing their journeys in the night sky. Neptune again is just up from Jupiter in between the constellation of Pisces (The Fish) and the constellation of Cetus.
Venus on the 15/08/22 at 6 am (AWST)
Mars, Jupiter, Saturn, Uranus and Neptune on the 15/08/22 at 6 am (AWST)
Mercury on the 015/08/22 at 7 pm (AWST)
Mars and Uranus on the 02/08/22 at 5 am (AWST)
PAGE 38
Astronomical Events: The Perseids Meteor Shower:
Unfortunately for us in Australia, the Perseids is The Perseids on the 13/08/22 at 6 am (AWST) very low on the horizon in the North around 6 am. This year the Moon is a Full Moon phase, so they will be reduced numbers from the light pollution from it.
Celestial Wonder To Look At This Month: The Dumbbell Nebula:
Dumbbell Nebula on the 15/08/22 at 9 pm (AWST)
The Dumbbell Nebula (M27 & NGC 6514) is a planetary nebula in the constellation Vulpecula (The little fox) of between 9-15,000 years of age. A planetary nebula is an emission nebula. It’s formed from a star than has blown off a shell of material in a nova-style explosion. Planetary nebulae are usually spherical style object and relatively small in size, which is why they look like planetary discs in small telescopes. They are very short-lived phenomena of a few tens of thousands of years which then fade out.
The nebula is nearly 3 light-years across and 1,360 light-years from Earth. The central star is the progenitor of the Dumbbell Nebula is a white dwarf star, ~5 % of the Sun’s diameter and ~50 % of its mass, making it larger than most other known white dwarfs.
2022 WINTER EDITION
The Perseids meteor shower is once again nearly upon us, with the peak night occurring on the night of the 12th/13th. The Perseids is a Northern Hemisphere shower, and they appear to come from the constellation Perseus, and that’s where they get their name from. The shower is active from about mid-July to the end of August. Normally, the meteor rate exceeds 100 meteors per hour.
PAGE 39
Messier 27
Image Credit: Mark Hanson
2022 WINTER EDITION
The Dumbbell Nebula
PAGE 40 2022 WINTER EDITION
Sunday Day Tours Sundays are perfect to take family and friends sightseeing on a beautiful drive through the Bickley Valley for a special Guided Day Tour of the Perth Observatory. Come up and see a jewel in the state’s history. See why the Observatory was so important to help the growth of WA and maybe see some Kangaroos as well. We’ll be doing guided site tours of the Observatory and solar experience tours at 1:30 pm, 2 pm, 2:30 pm and 3 pm. Guided Site Tour Learn more about Perth Observatory with stories from Mt Eliza (1896 to 1965), our move to Bickley in 1966 and what we’ve done since then. Step back in time in our museum and tour the Meridian, Astrograph & Calver Telescopes. Be enchanted with Worl Wangkiny and discover what we are doing now with the Lowell, RCOP and Obsession Telescopes. Solar Experience Tour See our Collins Sundial and learn how it works and what an analemma is. View the Sun safely through our Coronado Solar Telescope (If the weather permits) and be amazed at how sunspots and coronal mass ejections are created and how they cause the auroras here on Earth. Also, find out cool facts about the Sun and the space probes that are helping us learn more about it
Learn about the timekeeping the Perth Observatory did and why it was so important. Discover how photos were taken of the night sky and how they are taken today. Touch the Mundrabilla Meteorite and find out what meteors are.
Image Credit: Matt Woods
Museum Tour
PAGE 41
What’s In September’s Skies By Matt Woods
2022 WINTER EDITION
Planets: This month we will lose Mercury to the Sun’s glare in the early evening in the middle of September. Venus too will disappear into the Sun’s glare in the second week of the month in the early morning. Mars can be found in the constellation Taurus (The Bull), and it will pass close to the Red Giant star Aldebaran (The red eye of Taurus) at the end of the first week of September. It should be a nice view, with Taurus appearing to have two red eyes. Jupiter it can be found in between the constellation of Cetus (The Sea Monster) and the constellation of Pisces (The Fish) in the evening sky. On the 27th of September at 02:00 am (AWST), Jupiter will reach opposition and will be at its best to look at. Saturn can also be found in the evening sky in the constellation of Capricornus (The Sea-Goat). Uranus is rising in the early morning in between the constellation of Aries (The Ram) and the constellation of Taurus. Neptune again is just up from Jupiter in between the constellation of Pisces and the constellation of Cetus. On the 10th of September at 05:00 am (AWST), Neptune will reach opposition. Even though it’s the best time to see Neptune it’ll still will look like a blue dot.
Mars, Jupiter, Saturn, Uranus, and Neptune on the 16/09/22 at 3:00 am (AWST)
Astronomical Events: Zodiacal Light Season Begin: The Zodiacal Light season begins on the 1st of September. As the Sun approaches the September
PAGE 42
Zodiacal Light in front of the Milky Way
To see the zodiacal light, go out around an hour after sunset or an hour before dawn, and look from as darker a site as possible. 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 pyramidshaped glow, tracing the length of the ecliptic plane. The September Equinox: On Friday the 23rd of September, The Southward Equinox occurs at 09:03 am (AWST), marking the beginning of astronomical Fall for the Northern Hemisphere, and the start of Spring for the Southern Hemisphere. This is an 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 will fall on the 22nd or the 23rd until 2092, when it will begin falling on September 21st every fourth year. The Equinox (literally meaning ’equal nights’ in Latin) means 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 2022, the Harvest Moon falls on September 10th. The term Equilux is sometimes used to discern 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 zone. The Equilux occurs within a few days of either Equinox.
Celestial Wonder To Look At This Month: The Pegasus Globular Cluster: The Pegasus Globular Cluster (M15 & NGC 7078) is a globular cluster and it’s about 35,700 lightyears from Earth in the constellation Pegasus. It was discovered by Jean-Dominique Maraldi in 1746 and is estimated to be between 12.5 billion years old, which makes it one of the oldest known
2022 WINTER EDITION
Equinox on the 22nd of September causes the backscattering of light from 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 dawn or dusk. This is due to 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; and the reverse is true near the March equinox.
PAGE 43
globular clusters. It’s 175 light-years in diameter and is one of the most densely packed globular clusters known in the Milky Way galaxy. Its core has undergone a contraction known as “corecollapse” and it has a central density cusp with an enormous number of stars surrounding what may be a central black hole.
2022 WINTER EDITION
The Pegasus Cluster is home to over 100,000 stars, and the cluster is notable for containing many variable stars and pulsars, including one double neutron star system. It also contains the first planetary nebula discovered within a globular cluster in 1928. Just three others have been found in globular clusters since then. It can be observed with binoculars or a small telescope, appearing as a fuzzy star. Telescopes with a larger aperture (at least 6”) will start to reveal individual stars.
The Pegasus Globular Cluster on the 15/09/22 at 9 pm
PAGE 44
Messier 15
Image Credit: ESA/Hubble & NASA
2022 WINTER EDITION
The Pegasus Globular Cluster
PAGE 45 2022 WINTER EDITION
A Quick Look In The Astroshop!
PAGE 46
2022 WINTER EDITION
PAGE 47 45
SUPPORT PERTH OBSERVATORY
2022 WINTER SUMMEREDITION EDITION
CONTAINERS FOR CHANGE 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 refund depot, and use the Perth Observatory (Scheme ID: C10424615). POVG will receive 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 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. Thank you for helping the POVG promote sustainable and environmentally conscious practices and diversifying ways for us to raise much-needed funds. Your help supports the continuing upkeep and running of Western Australia’s oldest observatory!
PAGE 48 2022 WINTER EDITION
The Emu And Large Magellanic Cloud
Image Credit: Matt Woods
in the Central Wheatbelt
PAGE 49
2022 WINTER EDITION
PAGE 50
2022 WINTER EDITION
The Funny Side
Contact Us Perth Observatory 337 Walnut Road 6076 Bickley, WA (08) 9293 8255 newsletter@povg.org.au perthobservatory.com.au
