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Session Speakers

Session speakers are the mainstay of the RASNZ Conference, and are typically New Zealand based research astronomers, industries and societies covering their areas of work and discoveries. The 2023 RASNZ conference will cover a range of themes related to astronomy and astrophysics. The conference will provide an opportunity to discuss the latest advancements in facilities and research related to the field. Attendees will also be able to explore the latest techniques being used in astronomy research, and learn about the innovative ways that researchers are using technology to further our understanding of the universe. Overall, the conference promises to be a valuable forum for sharing knowledge and engaging in discussions about the latest developments in astronomy and astrophysics.

The following abstracts have been submitted for the 2023 RASNZ Conference. Final selection of presentations are yet to be confirmed.

Jan Eldridge - University of Auckland

What's JWST done so far...?

Since it's launch JWST has produced significant scientific results. I'll talk about some of the work I've been involved in a few different international research groups on the earliest high-redshift galaxies and dust producing Galactic stars. Then I'll end with discussing what results we'll see in the coming years.

Yvette Perrott - Victoria University of Wellington

What is dark matter? From MOA to galaxy clusters.

The vast majority of matter in the Universe is dark: we know it's there from its gravitational effects, but it doesn't emit light. I'll review current evidence for and theories about dark matter.

Grant Christie - Auckland Astronomical Society

The Auckland Astronomical Society Turns 100

Over the last century our Society has grown into an active, diverse and inclusive organisation. With over 600 members, we look forward to meeting the challenges of the future.

John Drummond - Gisborne Astronomical Society  University of Southern Queensland

Kiwis Who Caught Comets - Let's Look at Murray Geddes

Six New Zealanders have discovered comets from NZ shores. This talk briefly touches on them but will focus mostly on Murray Geddes, who RASNZ honours with the Murray Geddes Memorial Prize.

Need some inspiration?

Presenting at the RASNZ conference offers an excellent opportunity for astronomy enthusiasts to share their research, discoveries, and ideas with a supportive community of peers. It is a chance to engage with like-minded individuals, learn from experts in the field, and gain valuable feedback on your work. Moreover, the conference provides a platform for individuals to showcase their skills and knowledge, build new connections, and explore new avenues for collaboration. 


Alan Gilmore provided a brief overview of the presentations delivered by the speakers at the 2022 RASNZ conference, which are listed below. Whether you are looking for inspiration for your own presentation or simply seeking a glimpse of the exhilarating experience that awaits you at this year's conference, these talks are not to be missed! Get ready to be blown away by the cutting-edge research, fascinating stories, and groundbreaking discoveries that were shared by some of the brightest minds in the field.

Astrophysics Research

Modelling the Movements of Stars in Omega Centauri

Warwick Kissling presented his attempt to model the movements of stars in the Omega Centauri globular cluster, which contains around 10 million stars and has a mass 4 million times that of the Sun. The model started with 2000 stationary stars and computed their movements forward in 1000-year intervals for three billion years. While the model did a reasonable job matching the apparent density profile of stars, it failed to replicate the correct radial velocities and proper motions observed with HST. The talk concluded with two recent observational papers on Omega Centauri, each describing the motions of 100,000 stars.

Magnetic Fields in Peculiar A/B Stars

During his presentation, Benjamin Lowe discussed his analysis of peculiar A/B stars, which exhibit strong magnetic fields that levitate certain metals into the star's atmosphere and create "star spots" that rotate with the star. By using the HERCULES spectrograph on Mt John's 1-meter telescope, Ben was able to observe changes in a star's spectrum as star spots rotate toward and away from the observer. Interestingly, some stars have only one spot, while others have multiple spots.

Auckland University of Technology's Warkworth Radio Telescope and Very Long Baseline Interferometry

Sergei Gulyaev discussed the Warkworth radio telescope's involvement in high-precision very long baseline interferometry (VLBI), which combines outputs from radio telescopes across Australia and New Zealand to measure the position of radio stars with remarkable accuracy of 15-20 microarcseconds. This exceeds Gaia's 20-30 microarcseconds and allows for mapping of the spiral arms of our galaxy. The parallax of radio sources can be measured to determine galactic rotation, and measurements are tied into the International Celestial Reference Frame. Sergei also shared findings from the VLBI measurement of the distance to the white-dwarf pulsar AR Scorpii and its orbital separation from a red dwarf, with a period of 2 minutes and a four-hour orbit.

Home Observatory Instrumentation and Spectroscopic Results

Hamish Barker discussed the instrumentation at his home observatory in Nelson and the spectroscopic results. He began his astronomical spectrographic career in 2019 with the spectra of the nova asassn-19qy in the Large Magellanic Cloud (LMC), which was obtained with a star analyser grating and DSLR camera through a 200mm aperture Dobsonian telescope on an equatorial platform. He now uses the same optical tube and summarised some current star surveys from which automated transient alerts are generated. Spectra of stars to 11th magnitude can be obtained with a low-cost Star Analyser 100 or 200 grating in sparse regions, to 9th magnitude in crowded regions.

Understanding the Enigma of Dark Matter: Current Research and Challenges

Richard Easther discusses Dark Matter: its mysterious nature, proposed candidates, and the challenges of detecting it. It accounts for 25% of the universe's material and 80% of the Milky Way's mass, but we don't know what it is made of, and it doesn't interact with light. Attempts to explain it by different physics and to detect it have been unsuccessful. GAIA may provide an observational test, and Richard's favorite candidate is ultralight DM with particles 10-27 the mass of the electron, which would have a long quantum wavelength.

Modelling Star Pulsation: Insights on Double-Mode Cepheids and RR Lyrae Stars

Rhia Hewett explained the complex physics involved in modeling star pulsations, using the double-mode Cepheid U Triangulum Australis as an example. Despite Covid-related interruptions to observations, the team obtained reliable photometric data from the MOA 1.8-metre telescope. Rhia was able to develop a basic physical model that matched the observations and plans to expand her research to include double-mode RR Lyrae stars found in globular clusters.

Space Exploration and Observation

The Mystery of the Possible Meteorite: A Story of Chance Discovery

Alastair Brickell shares the story of a possible meteorite discovery in New Plymouth, with a rock found by Stephen McClutchie that looks igneous and porous. The rock has no fusion crust but some meteorites don't have it, and it has some green paint on it matching metal doors close by. While a geologist suggested it looked like a Taranaki Andesite, its origin is still uncertain.

The LISA Mission: Detecting Gravitational Waves and Exploring the Universe

Emily Kendall presents the LISA mission, a European Space Agency project, which includes several New Zealand scientists. LISA will be a low-frequency gravitational wave detector consisting of three spacecraft arranged in an equilateral triangle, searching for gravitational waves in the frequency range of 0.1mHz to 100mHz caused by supermassive black hole mergers. Professor Renate Meyer leads the Aotearoa New Zealand LISA team, which will investigate matched filtering to detect weak gravity waves in the noise and consider how dark matter might affect black holes approaching each other. The NZ Gravity Wave Working Group is part of the LISA consortium.

The Threat of Satellite 'Constellations' to Astronomy: Challenges and Possible Remedies

John Hearnshaw discusses the impact of satellite "constellations" on astronomy. Companies like SpaceX are planning to launch thousands of satellites for internet communications, with at least 12,000 satellites weighing between 100-500 kg each. Currently, there are 2666 active satellites in orbit, but in the next decade, that number could reach 100,000 in low Earth orbit. These satellites photobomb astronomical imaging, degrading or preventing scientific work. Solutions proposed include darkening satellites and controlling their orientation to minimize reflected light. However, there is currently no treaty protecting astronomy, despite existing treaties on the peaceful uses of space.

ESA's PLATO Mission: Searching for Planetary Transits and Stellar Vibrations

John Bray discusses ESA's PLATO mission, which will search for planetary transits and star oscillations. It will launch in 2026 and observe two areas of sky for two years each using four groups of six cameras. The cameras will have a large field of view, and can detect planet transits as small as 0.5 Earth masses. However, the large pixel size may cause false positives when a faint eclipsing binary star is included with a bright star.

The Evolution of Our Understanding of the Universe: A Historical Overview

John Hearnshaw provided a historical account of the concepts of the Universe and our place within it. From Aristotle's postulation of a geocentric universe to the Hubble-Lemaître law and the Big Bang cosmology, the presentation covered a wide range of developments in our understanding of the universe. Notable contributors to our knowledge include Aristarchus, Copernicus, Galileo, and Alexander Friedmann, to name a few. The presentation concluded by noting the insignificance of our place in the Universe, as eloquently stated by Carl Sagan as our existence on a "pale blue dot".

Developments and thoughts in New Zealand Astronomy

Preserving Dark Skies: The Role of Legislation and International Conventions

Steve Butler presented his efforts to promote dark skies through public awareness and legislation, including regulations set by Acts of Parliament and National Policy Statements. Local government implements these regulations in District Plans, while international conventions such as the Convention on Conservation of Migratory Species also have an impact. Steve has been involved in submissions to Parliamentary select committees on lighting and has helped adopt the National Light Pollution Guidelines for Wildlife. The standard AS/NZS 4282 provides some protection for astronomical observatories, and the RASNZ has established a register for this purpose. The document "Environment Aotearoa 2022" highlights the importance of good night sky awareness.

Decline in Amateur Astronomers’ Involvement in Research over the Past Three Decades.

In the past three decades, amateur astronomers' involvement in research has declined, according to Stan Walker. In the mid-1960s, there were many active observers in New Zealand, particularly around Auckland Observatory, where variable star observing was popular. Ronald McIntosh of Auckland encouraged everyone to observe, record and publish. The Edith Winstone Blackwell telescope was funded through his prominence, and several groups used it to conduct photoelectric photometry. Long-term observations of stars like QZ Carinae were also made, with 55 years of observations discussed in ‘Southern Stars’ in 2017. Now, only three active variable star observers remain in New Zealand, and the Variable Stars South director is based in New South Wales.

Review of the RASNZ's Professional Astronomers Group and Future Goals

Nick Rattenbury discussed the RASNZ’s Professional Astronomers Group (PAG), which represents professional astronomy in NZ. He highlighted that astronomy currently has no representation on national councils and suggested that closer relations with various organizations could be beneficial. The way forward, as Nick sees it, is to define the needs of the astronomical community, figure out the skill sets required, and inform the RASNZ Council that there is a need to reconsider the PAG goals, membership, rights, and responsibilities.

Emerging Trends in Astronomical Outreach in NZ.

Nalayini Davies, the incoming RASNZ President, reviewed the past year's astronomical outreach in New Zealand, which included the launch of the Dark Sky Network and Aotearoa Astro-tourism Academy, the adoption of a formal Matariki holiday, the 'Scopes in Schools' project, and the eVscope science network. She noted that the dark sky movement is a fast-growing component of global tourism and can benefit the New Zealand economy immensely, and highlighted the eVscope Digital Telescope as a user-friendly and accessible tool for amateur astronomers and students alike.

Navigating the New Incorporated Societies Act 2022

Peter Felhofer discussed the challenges of running an incorporated society in the 21st century. He emphasized the need to adhere to the new Incorporated Societies Act 2022, which requires all societies to re-register by 2025. He advised larger organizations to consider a trust structure. It is essential to protect the society's name, trading name, and internet name. A society officer's email address should reflect the society's name, and the society should own its name and register its domain name. Peter also recommended the use of apps like My Events and Sharepoint to facilitate meeting organization and public liability insurance.

Astronomy Education

Exploring the Universe: Teaching and Research at the University of Canterbury Mt John Observatory

Karen Pollard discussed the teaching program and research conducted at the University of Canterbury Mt John Observatory. Research projects include long-term spectral observations of pulsating stars, proto-planetary disks, binary and multiple stars, and the massive binary system of Eta Carina. A recent study of a quadruple star system found that close binary pairs may eventually merge, potentially leading to a Type 1a supernova explosion. Shock waves, rather than nuclear fusion, were found to cause most of the brightness from a stellar nova.

Encouraging SWAPA Students to Consider Astronomy as a Tertiary Subject

Leah Albrow shared her experiences studying astrophysics at Canterbury University during her third undergraduate year. She urged SWAPA students to consider astronomy as a tertiary subject and emphasized the importance of hands-on experience and fact-checking information. Due to Covid, most of the past two years of her studies have been online, but field trips to Mt John have still been organized. Leah also stressed the need for preparation and adaptability in case of limited access to lab work.

Special thanks to Alan Gilmore for summarising these talks. This information was collected and adapted from:

Royal Astronomical Society of New Zealand. (2022). Southern Stars, September 2022. eSS, 61(3), 6-9.

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