Talk

The recent establishment of the Swan Reach Observatory (SRO) will be a boon to optical astronomy in South Australia. It is based around a 70cm research-grade corrected Dall-Kirkham telescope (Planewave CDK700), and as such is the highest quality telescope in the State. It is housed in an air-conditioned 20m x 30m roll-off roof shed with reception, kitchenette and toilet facilities. Researchers and students will have access to a facility which has previously never been available to them locally. The proximity to the amenities of the nearby township of Swan Reach significantly add to the utility of this Observatory.

The Observatory is located in the River Murray International Dark Sky Reserve (RMIDSR), which is Australia’s first Dark Sky Reserve and one of only 25 in the world. In addition to its dark skies, the area is known for its dry climate and cloudless skies. Although the details are currently under negotiation, it is envisaged that the Observatory will be the basis of STEM activities for school students, and for collaborative research endeavours with academic colleagues. Particularly in the latter case, we anticipate that research findings will be published in professional astronomical journals.

Details of the telescope and observatory will be presented, and potential applications discussed.

There is growing interest in the preservation of dark skies. This stems not only on from concern about the effect of light pollution on optical astronomy, but also on human and wildlife health and well-being. Astrotourism is a growth market, with over 250 designated International Dark Sky Places (IDSPs) currently established across more than 22 countries on six continents. Accreditation requires measurement of the sky darkness on an annual basis to ensure that it maintains its darkness to a suitable level. However, the methodology behind this is only loosely defined, allowing for a wide interpretation of the readings.

We present on a long baseline measurement of the sky darkness at the River Murray International Dark Sky Reserve (RMIDSR), the first such Reserve to be accredited in Australia. Readings were taken every minute and filtered for environmental factors such as the presence of the Moon or clouds. Values in excess of 21.9 mag/square arc second were recorded, with 22.0 usually taken to be the value for a ‘perfectly’ dark sky. Rather than using a simplistic averaging of values, which is meaningless for logarithmic values such as these, we developed a statistical method to estimate sky darkness to a pre-defined percentile. We believe that this has the potential to be the basis for dark sky estimations internationally.

This is a lighthearted trip across about 20 years of amateur astronomical activities, mostly variable star observing. It starts with visual estimates of the magnitudes of variable stars, moves on to photoelectric photometry (PEP), abandons laborious PEP for DSLR photometry and ends with a monochromatic CMOS astronomical camera (actually, two of them one at a time), a filter wheel and scientific filters. Along the way there are serious looks at light curves that reveal the true natures of stars and the ways in which they can be analysed to yield new publishable data. There are various instruments starting with a pair of 7x50 binoculars, a 10” f/5 push-to Dobsonian, a brief love affair with an 18” f/5 truss-tube Dobsonian fitted after a while with an Argo Navis telescope computer, 80mm and 120mm f/7.5 ED refractors on equatorial mounts which gave me some of my most fruitful data, and finally a 200mm f/10 Schmidt-Cassegrain instrument on (of all things) an equatorial wedge. As the title says there are confessions, which are about what perhaps should and should not have been done, but there are no regrets.

Mount Burnett Observatory has had a thriving Young Observers Program for many years. In 2025, I stepped in as the new YO coordinator and would like to share some of the strategies that have made the program an enduring success. A mixed cohort of children, roughly ages 5 to 16, meet monthly at the clubhouse. A team of volunteers delivers a structured program that allows for knowledge building, interactivity between children, hands-on learning activities, observing (when the weather graciously permits) and general mayhem. This paper will explore some of the ways we keep the project engaging, and offer suggestions for starting a YO program in your own organisation.

In addition to many diseases and conditions that only affect some people, a few inescapable age-related factors affect all observers vision as we age. These are decreased maximum pupil dilation, low-light sensitivity, and rate of dark adaption. By understanding these problems, older observers can implement observing techniques, behaviours and hygiene measures to minimise the deleterious effects on observing enjoyment.

Supplementary material
For anyone wanting more information about Joe Cali's talk, the link below to Joe's web page has links to a series of short articles covering the material / subject areas in the talk, the slides in PDF format, and an excel spreadsheet for generating light loss tables as equivalent smaller telescope apertures of the type displayed during the talk. All files can be downloaded from Joe's web site at this URL: -
https://joe-cali.com/NACAA/

This 90 minute presentation series will highlight the way professional and amateur astronomers, living and observing under different conditions and in different states of Australia, have contributed to solar, variable star, eclipse, comet and other astronomical observations. There will be a short introduction to the new History of Australian Astronomy Chapter of the Astronomical Society of Australia explaining how amateur astronomers can contribute to this area of research.

• Introduction – History of Australian Astronomy Chapter of the ASA by Toner Stevenson, in person (3 mins)
• ‘Perth Observatory, discovering astronomical history in the archives’ by Craig Bowers, online (20 mins)
• ‘Rosina Dafter, Queensland's brilliant variable star astronomer’ by Toner Stevenson, in person (18 mins)
• ‘Barry Adcock’s 66 Year Journey as an amateur astronomer in Victoria’ by Judith Bailey, in person (20 mins)
• ‘Three Queensland Observers of the 21st September, 1922 Total Solar Eclipse’ by Peter Esca Anderson, delivered on behalf of Peter by Toner Stevenson (18 mins)

Perth Observatory, discovering astronomical history in the archives
Presented by: Craig Bowers
The State-owned Perth Observatory had existed in Western Australia for over one hundred and seventeen years by the time it was closed for research in 2013. It had served a Colony and a State in delivering various scientific services to the people and the government of the day, as well as contributing to the international astronomical and scientific knowledge base. In this presentation I will highlight what the archives have revealed about the endeavours and achievements of the astronomers who worked there.

Rosina Dafter, Queensland's brilliant variable star astronomer
Presented by: Toner Stevenson
Rosina Dafter migrated from England to Brisbane in 1910. In 1923 she became an amateur astronomer, joining the NSW branch of the British Astronomical Association and Astronomical Society of Queensland. She was prolific in her observations of variable stars and in 1937 Dafter became the first Australian woman to be elected a Fellow of the Royal Astronomical Society. As well as her achievements there were also challenges due to her gender.

Three Queensland Observers of the 21st September, 1922 Total Solar Eclipse
Presented by: Peter Esca Anderson
This presentation discusses three remarkable Queensland amateur observers of the total solar eclipse that occurred in 1922: James Park Thomson, Dudley Eglinton and John Beebe. Thompson observed the eclipse from Goondiwindi, Eglington conducted his observations from a rooftop in Brisbane and Beebe was at Stanthorpe. I also briefly outline how each played a key role in the development of astronomy in Brisbane.

Barry Adcock’s Journey Student to amateur astronomer in Victoria 1957- present
Presented by: Judith Bailey
This presentation will highlight Barry Adcock’s lifetime of commitment to Amateur Astronomy, a journey beginning with building his own telescope. In 1990 Barry received the NACAA Page Medal in for telescope design work and planetary observations including his dedication to observing the planet Jupiter. His leadership of the ASV Planetary Section, and then as ASV President as well as sharing his expertise with many Astronomical Societies Conferences at a local and international level as well as many other achievements will be included. Most recently Barry was awarded the BAA Horace Dall Medal for a marked ability in the making of astronomical instruments.

A full day program of presentations by members of the Australian and New Zealand occultation observing community. Topics covered include observation results and analysis as well as presentation on observing techniques, technology and potential future observing projects. This meeting will appeal to both seasoned occultation observers as well as offering support and advice to new observers. Presenters and attendees will be in person and remote via Zoom.

As urban light pollution increasingly obscures our connection to the night sky, astrotourism offers a compelling solution. This talk highlights the transformative power of astrotourism in educating communities about light pollution and fostering sustainable practices.

Join us to explore how astrotourism can serve as a vital tool for reducing light pollution and ensuring that future generations can appreciate the beauty of a clear, starry night. Together, we can illuminate the importance of preserving our dark skies for both nature and society.

We will give an overview of current science activities in ASSA, particularly in occultations, variable stars and radio astronomy.

From our newly revived Occultations Group, we will discuss the observational techniques that we use in our group, and in particular we will analyse two double star discoveries, one with two distinct shadows of an asteroid, the other with six separate occultation observations of a tight double.

On the variable star observing (VSO) front, the rise of easily accessibly tooling enabled Jake Lancaster to detect, in his own archived dataset, a flare star that rapidly brightened by several magnitudes and then diminished over a few hours. The Bob Nelson Eclipsing Binary O-C database, now managed by Robert Jenkins in South Australia, continues to grow. In 2025, 6710 new observations were added to the database on 1215 star systems; 200 of which are systems that had no previous data. Andrew Murphy and David Benn have been using Seestar for VSO and Andrew has practical insights to share. David Benn continues to enhance the multi-platform VStar tool.

Over the last few decades, progress in networking and sharing telescope resources has come a long way from dialup modems sharing tiny CCD images across home telephone lines up to the current large-scale telescope networks used for education such as SkyNet, Las Cumbres Observatory and NextAstronomy. It is now the time in the development of these networks that economical large-scale sharing of resources is available to users from amateurs, youth up to graduate students and beyond and from simple colour images to long-term research projects like exoplanet monitoring.
This talk will provide a unique perspective of how to tap into the immense potential of robotic telescope access and sharing in the resources for education, outreach and research that it brings.
This talk will provide a brief overview of the history of robotic telescopes, the current landscape, the range of tools and networks available as well as possibilities and inevitabilities for the future of robotic telescopes, student research and education.