BEGIN:VCALENDAR VERSION:2.0 PRODID:-//jEvents 2.0 for Joomla//EN CALSCALE:GREGORIAN METHOD:PUBLISH BEGIN:VTIMEZONE TZID:Australia/Sydney BEGIN:STANDARD DTSTART:20200405T020000 RDATE:20201004T030000 TZOFFSETFROM:+1100 TZOFFSETTO:+1000 TZNAME:Australia/Sydney AEST END:STANDARD BEGIN:STANDARD DTSTART:20210404T020000 RDATE:20211003T030000 TZOFFSETFROM:+1100 TZOFFSETTO:+1000 TZNAME:Australia/Sydney AEST END:STANDARD BEGIN:STANDARD DTSTART:20220403T020000 RDATE:20221002T030000 TZOFFSETFROM:+1100 TZOFFSETTO:+1000 TZNAME:Australia/Sydney AEST END:STANDARD BEGIN:STANDARD DTSTART:20230402T020000 RDATE:20231001T030000 TZOFFSETFROM:+1100 TZOFFSETTO:+1000 TZNAME:Australia/Sydney AEST END:STANDARD BEGIN:STANDARD DTSTART:20240407T020000 RDATE:20241006T030000 TZOFFSETFROM:+1100 TZOFFSETTO:+1000 TZNAME:Australia/Sydney AEST END:STANDARD BEGIN:STANDARD DTSTART:20250406T020000 RDATE:20251005T030000 TZOFFSETFROM:+1100 TZOFFSETTO:+1000 TZNAME:Australia/Sydney AEST END:STANDARD BEGIN:STANDARD DTSTART:20260405T020000 RDATE:20261004T030000 TZOFFSETFROM:+1100 TZOFFSETTO:+1000 TZNAME:Australia/Sydney AEST END:STANDARD BEGIN:STANDARD DTSTART:20270404T020000 RDATE:20271003T030000 TZOFFSETFROM:+1100 TZOFFSETTO:+1000 TZNAME:Australia/Sydney AEST END:STANDARD BEGIN:STANDARD DTSTART:20280402T020000 RDATE:20281001T030000 TZOFFSETFROM:+1100 TZOFFSETTO:+1000 TZNAME:Australia/Sydney AEST END:STANDARD BEGIN:DAYLIGHT DTSTART:20200331T193000 RDATE:20200405T020000 TZOFFSETFROM:+1000 TZOFFSETTO:+1100 TZNAME:Australia/Sydney AEDT END:DAYLIGHT BEGIN:DAYLIGHT DTSTART:20201004T030000 RDATE:20210404T020000 TZOFFSETFROM:+1000 TZOFFSETTO:+1100 TZNAME:Australia/Sydney AEDT END:DAYLIGHT BEGIN:DAYLIGHT DTSTART:20211003T030000 RDATE:20220403T020000 TZOFFSETFROM:+1000 TZOFFSETTO:+1100 TZNAME:Australia/Sydney AEDT END:DAYLIGHT BEGIN:DAYLIGHT DTSTART:20221002T030000 RDATE:20230402T020000 TZOFFSETFROM:+1000 TZOFFSETTO:+1100 TZNAME:Australia/Sydney AEDT END:DAYLIGHT BEGIN:DAYLIGHT DTSTART:20231001T030000 RDATE:20240407T020000 TZOFFSETFROM:+1000 TZOFFSETTO:+1100 TZNAME:Australia/Sydney AEDT END:DAYLIGHT BEGIN:DAYLIGHT DTSTART:20241006T030000 RDATE:20250406T020000 TZOFFSETFROM:+1000 TZOFFSETTO:+1100 TZNAME:Australia/Sydney AEDT END:DAYLIGHT BEGIN:DAYLIGHT DTSTART:20251005T030000 RDATE:20260405T020000 TZOFFSETFROM:+1000 TZOFFSETTO:+1100 TZNAME:Australia/Sydney AEDT END:DAYLIGHT BEGIN:DAYLIGHT DTSTART:20261004T030000 RDATE:20270404T020000 TZOFFSETFROM:+1000 TZOFFSETTO:+1100 TZNAME:Australia/Sydney AEDT END:DAYLIGHT BEGIN:DAYLIGHT DTSTART:20271003T030000 RDATE:20280402T020000 TZOFFSETFROM:+1000 TZOFFSETTO:+1100 TZNAME:Australia/Sydney AEDT END:DAYLIGHT BEGIN:DAYLIGHT DTSTART:20281001T030000 RDATE:20290401T020000 TZOFFSETFROM:+1000 TZOFFSETTO:+1100 TZNAME:Australia/Sydney AEDT END:DAYLIGHT END:VTIMEZONE BEGIN:VEVENT UID:c07c959e56b25d8e19a1c65b56cfa3a9 CATEGORIES:Guest Speaker Night CREATED:20210329T213443 SUMMARY:Guest Speaker - Dr Ian Kemp (ICRAR) LOCATION:Zoom Meeting - members will be invited DESCRIPTION:Space rocks and chaotic orbits: could Earth have a hidden companion?Nothing could be more boring than a rock going round in orbit for millions of year s, right? Well as usual, Ian begs to differ, and will take you on a quick t our of some of the features of orbits that you may not have come across bef ore.\nThe elliptical orbit under the influence of gravity was solved theore tically by Isaac Newton in the 1600s, and his equations are usually used to day, to calculate orbits of planets, moons, comets, near-Earth asteroids, a nd spacecraft. There are only two slight problems - firstly, the equations cannot actually be solved if there are more than two bodies involved (which is usually the case, eg. Earth-Moon-Spacecraft); and secondly the equation s are actually incorrect anyway because they don't include time dilation du e to velocity and gravity. The only way to understand orbits long term is t o use supercomputer modelling.\n \nIn this talk we will quickly run through some of the consequences of the 'three body problem' and the limitations o f Newton's model of gravity. Orbit swaps, drastic variations in Earth's orb it round the Sun, and the underlying chaotic nature of orbits in general. T he fact that all orbits are inherently unstable opens up an interesting que stion.... could another body share Earth's orbit? If so, how could it get t here? And if not, why not? Ian will outline some original research into whe ther there might be something very interesting lurking at one of the Earth- Sun Lagrange points.\n \nAs a finale we will look at orbits in the framewor k of general relativity - and find out if this makes things easier, or hard er to understand.\nDr Ian KempAstonomer at ICRAR - International Centre for Radio Astronomy ResearchI started my working life in the UK steel industry . After gaining a 1st class honours degree and PhD in Metallurgy at the Uni versity of Leeds, I pursued an academic career initially at the University of Wales, then at the BHP Melbourne Research Laboratories in Melbourne, Vic toria. During this period I achieved a number of Journal publications and C onference Presentations in the field. I later moved into more applied work in Steel Processing, Data Management and Technology Deployment, in industri es including Steel manufacture, government, and Oil & Gas. The latter i ncluded two years in the Pilbara (NW Australia) managing a range of process improvement projects. In my later career my focus was on Project Managemen t though I maintained a technical focus and was awarded a patent relevant t o reducing the environmental impact of offshore operations.\nThrough all th is time I maintained an interest in astronomy, and gained a Graduate Diplom a and Masters Degree in Astronomy from Swinburne University (Victoria) by d istance learning.\nI recently joined ICRAR as a full time researcher after many years as an enthusiastic amateur astronomer. I am pursuing a number of smaller projects as I discover where my main research interests lie. A cou ple of my research areas are extensions to short projects carried out for m y Masters Degree in Astronomy.\nDATA INTENSIVE ASTRONOMY\nDeveloping standa rdised data flows to process the large flow of data from the new FAST radio astronomy dish in Southwest China.\nCATACLYSMIC VARIABLE STARS\nI am study ing a type of variable star known as UGSU, which consists of a binary syste m in which a medium-sized red star orbits a more massive white dwarf. These are the precursor systems to the ‘type 1a supernovae’, which are very impo rtant phenomena in Astronomy In these systems the red companion spills matt er onto the white dwarf, creating an accretion disk. From time to time the disk becomes gravitationally unstable and collapsed onto the WD, causing th e system to brighten by a factor of 10,000 or so. By studying the light emi tted during this collapse we can learn about the behaviour and possible ult imate destruction of the system.\nEARTH’S TROJAN POINTS\nIt is possible for asteroids, rocks, and dust to share Earth’s orbit, if they can become boun d to one of the ‘Lagrange Points’ which sit ahead of and behind Earth in it s orbit. My work based on dynamical modelling using the Swinburne supercomp uter has established the criteria for large objects to maintain a stable ‘t adpole’ or ‘horseshoe’ orbit as a partner of Earth. I am extending this wor k to look at the possibility of primordial gas and dust being retained – fo r these small particles the models need to include the effects of radiation pressure and light drag.\nEVOLUTION OF ‘GREEN VALLEY’ GALAXIES\nI am inves tigating the evolution of galaxies as they transition from the blue cloud t o the red sequence (if in fact they do transition!) – specifically looking for correlations with the gas content of the galaxies. This work is under t he direction of Ivy Wong and Barbara Catinella at ICRAR.\n X-ALT-DESC;FMTTYPE=text/html:

Space rocks and chaotic orbits: could Earth have a hidden companion?

Nothing could be more boring than a rock going round in orbit for mill ions of years, right? Well as usual, Ian begs to differ, and will take you on a quick tour of some of the features of orbits that you may not have com e across before.

The elliptical orbit under the influence of gravity was solved theoretically by Isaac Newton in the 1600s, and his equations ar e usually used today, to calculate orbits of planets, moons, comets, near-E arth asteroids, and spacecraft. There are only two slight problems - firstl y, the equations cannot actually be solved if there are more than two bodie s involved (which is usually the case, eg. Earth-Moon-Spacecraft); and seco ndly the equations are actually incorrect anyway because they don't include time dilation due to velocity and gravity. The only way to understand orbi ts long term is to use supercomputer modelling.

In this talk we will quickly run through some of the consequences of the 'three body probl em' and the limitations of Newton's model of gravity. Orbit swaps, drastic variations in Earth's orbit round the Sun, and the underlying chaotic natur e of orbits in general. The fact that all orbits are inherently unstable op ens up an interesting question.... could another body share Earth's orbit? If so, how could it get there? And if not, why not? Ian will outline some o riginal research into whether there might be something very interesting lur king at one of the Earth-Sun Lagrange points.

As a finale we wi ll look at orbits in the framework of general relativity - and find out if this makes things easier, or harder to understand.

Dr Ian Kemp photoDr Ian Kemp

Astonomer at ICRAR - International Centre for Radio Astronomy Research

I started my work ing life in the UK steel industry. After gaining a 1st class honours degree and PhD in Metallurgy at the University of Leeds, I pursued an academic ca reer initially at the University of Wales, then at the BHP Melbourne Resear ch Laboratories in Melbourne, Victoria. During this period I achieved a num ber of Journal publications and Conference Presentations in the field. I la ter moved into more applied work in Steel Processing, Data Management and T echnology Deployment, in industries including Steel manufacture, government , and Oil & Gas. The latter included two years in the Pilbara (NW Austr alia) managing a range of process improvement projects. In my later career my focus was on Project Management though I maintained a technical focus an d was awarded a patent relevant to reducing the environmental impact of off shore operations.

Through all this time I maintained an interest in a stronomy, and gained a Graduate Diploma and Masters Degree in Astronomy fro m Swinburne University (Victoria) by distance learning.

I recently jo ined ICRAR as a full time researcher after many years as an enthusiastic am ateur astronomer. I am pursuing a number of smaller projects as I discover where my main research interests lie. A couple of my research areas are ext ensions to short projects carried out for my Masters Degree in Astronomy.

DATA INTENSIVE ASTRONOMY
Developing standardised data flows to pr ocess the large flow of data from the new FAST radio astronomy dish in Sout hwest China.

CATACLYSMIC VARIABLE STARS
I am studying a type of variable star known as UGSU, which consists of a binary system in which a m edium-sized red star orbits a more massive white dwarf. These are the precu rsor systems to the ‘type 1a supernovae’, which are very import ant phenomena in Astronomy In these systems the red companion spills matter onto the white dwarf, creating an accretion disk. From time to time the di sk becomes gravitationally unstable and collapsed onto the WD, causing the system to brighten by a factor of 10,000 or so. By studying the light emitt ed during this collapse we can learn about the behaviour and possible ultim ate destruction of the system.

EARTH’S TROJAN POINTS
It is possible for asteroids, rocks, and dust to share Earth’s orbit, if t hey can become bound to one of the ‘Lagrange Points’ which sit ahead of and behind Earth in its orbit. My work based on dynamical modellin g using the Swinburne supercomputer has established the criteria for large objects to maintain a stable ‘tadpole’ or ‘horseshoe&rsqu o; orbit as a partner of Earth. I am extending this work to look at the pos sibility of primordial gas and dust being retained – for these small particles the models need to include the effects of radiation pressure and light drag.

EVOLUTION OF ‘GREEN VALLEY’ GALAXIES
I a m investigating the evolution of galaxies as they transition from the blue cloud to the red sequence (if in fact they do transition!) – specific ally looking for correlations with the gas content of the galaxies. This wo rk is under the direction of Ivy Wong and Barbara Catinella at ICRAR.

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