The OVV blazar 3C 446 was monitored over seven months in 1997 with ground based telescopes and instruments on ESA's Infrared Space Observatory (ISO). The aim was to try to detect variations in the IR and see if these were correlated with optical variations. The object varied in the optical and near-IR during this period, but did not vary in the far-IR. Despite being a factor of ten weaker than in 1983, the optical-IR SED exhibited the same slope. The new far-IR observations from ISO allow us to determine the location of the turnover in the spectrum, caused by synchrotron self-absorption. It occurs just longwards of 100 μm.

The astronomical technique of gravitational microlensing provides new opportunities to make measurements which are difficult or impossible by other methods, or which are complementary to those obtained more directly. These include detection of dark matter, determination of galactic structure, measurement of limb darkening of stars, and searches for extra-solar planets. The technique is best suited to the southern sky, and several observations have been made from Australasia. A sample of these observations is described here. A case is also made for a telescope at the Antarctic dedicated to gravitational microlensing.

This paper presents (Hα + [Nii]) imaging and spectroscopy of a previously unknown, highly evolved planetary nebula of low excitation which is in the first stages of an interaction with the interstellar medium (ISM). It was discovered serendipitously from AAO/UKST Hα Survey images as part of a project to exploit the survey data and has evaded detection by previous surveys due to its very low surface brightness. It is a remarkable hollow-sphere planetary nebula, some 19´ across, making it one of the largest examples of its type. We estimate a radius of 1.5 pc and a distance of 550 pc as derived from a new Hα surface brightness–radius relation. PFP 1 has near-perfect circular symmetry, broken only at the north-western edge which is coupled with significantly increased (Hα + [Nii]) intensity, both of which provide evidence for an interaction with the ISM. We find a near solar composition for this object with possibly enhanced He and N abundances. A blue central star candidate has been identified from the SuperCosmos Sky Survey data.

An enormous effort is underway worldwide to attempt to detect gravitational waves. If successful, this will open a new frontier in astronomy. An essential portion of this effort is being carried out in Australia by the Australian Consortium for Interferometric Gravitational Astronomy (ACIGA), with research teams working at the Australia National University, University of Western Australia, and University of Adelaide involving scientists and students representing many more institutions and nations. ACIGA is developing ultrastable high-power continuous-wave lasers for the next generation interferometric gravity wave detectors; researching the problems associated with high optical power in resonant cavities; opening frontiers in advanced interferometry configurations, quantum optics, and signal extraction; and is the world's leader in high-performance vibration isolation and suspension design. ACIGA has also been active in theoretical research and modelling of potential astronomical gravitational wave sources, and in developing data analysis detection algorithms. ACIGA has opened a research facility north of Perth, Western Australia, which will be the culmination of these efforts. This paper briefly reviews ACIGA's research activities and the prospects for gravitational wave astronomy in the southern hemisphere.

The Antarctic Plateau provides the best terrestrial sites for infrared (IR) and submillimetre (sub-mm) astronomy. In this paper we examine the relative importance of temperature, aerosol content and precipitable water vapour to determine which parameters have the greatest influence on atmospheric transmission and sky brightness. We use the atmospheric modelling program MODTRAN to model the observed sky spectrum at the South Pole from the near-IR to the sub-mm. We find that temperature and aerosol content determine the quality of near-IR observing conditions, aerosol content is the determining factor in the mid-IR up to 20 μm, while at longer wavelengths, including the sub-mm, it is the water vapour content that matters. Finding a location where aerosol levels are minimised is a key constraint in determining the optimum site on the Antarctic Plateau for an IR observatory.

Radio continuum emission due to thermal bremsstrahlung and optical Hα spectral line emission arise from processes involving similar atomic entities and physical conditions. The relationship between the flux density of the emission from the two processes is mainly a function of the electron temperature of the emitting region, modified by other factors such as the mode of radiation transfer in the hydrogen spectrum. On the other hand, radio continuum radiation due to non-thermal synchrotron emission is formed by species and processes not involved in thermal emission. As a consequence, differences between the observed radio continuum emission and Hα emission from cosmic sources can provide reliable information on a variety of important physical aspects of the sources, including the relative importance of thermal and non-thermal radio emission and the degree of optical obscuration. This paper reviews the theory of the formation of Hα and the radio continuum in the interstellar medium (ISM), discusses some of the factors that must be considered in comparing observations made in the two frequency regimes, and summarises the properties of some classes of galactic object that emit both optical and radio radiation.

The propagation of the highest energy cosmic rays through the 2·7 K microwave background is considered. Photo-pion production interactions cause energy losses for primary cosmic ray protons which result in significant energy degradation over intergalactic distances. The process of energy loss is discussed and an estimate is made of the average distances travelled for observed cosmic rays with a range of energies, assuming a power law source spectrum. At energies over 1020 eV, the average distances travelled are a few tens of megaparsecs, limiting possible sources to the volume dominated by the supergalactic plane.

PILOT (the Pathfinder for an International Large Optical Telescope) is a proposed 2.5-m optical/infrared telescope to be located at Dome C on the Antarctic plateau. The atmospheric conditions at Dome C deliver a high sensitivity, high photometric precision, wide-field, high spatial resolution, and high-cadence imaging capability to the PILOT telescope. These capabilities enable a unique scientific potential for PILOT, which is addressed in this series of papers. The current paper presents a series of projects dealing with the nearby Universe that have been identified as key science drivers for the PILOT facility. Several projects are proposed that examine stellar populations in nearby galaxies and stellar clusters in order to gain insight into the formation and evolution processes of galaxies and stars. A series of projects will investigate the molecular phase of the Galaxy and explore the ecology of star formation, and investigate the formation processes of stellar and planetary systems. Three projects in the field of exoplanet science are proposed: a search for free-floating low-mass planets and dwarfs, a program of follow-up observations of gravitational microlensing events, and a study of infrared light-curves for previously discovered exoplanets. Three projects are also proposed in the field of planetary and space science: optical and near-infrared studies aimed at characterising planetary atmospheres, a study of coronal mass ejections from the Sun, and a monitoring program searching for small-scale Low Earth Orbit satellite debris items.

Galaxy groups have been under-studied relative to their richer counterparts — clusters. The Group Evolution Multiwavelength Study (GEMS) aims to redress some of the balance. Here we describe the GEMS sample selection and resulting sample of 60 nearby (< 130 Mpc) galaxy groups and our multiwavelength dataset of X-ray, optical, and Hı imaging. ROSAT X-ray images of each group are presented. GEMS also utilizes near-infrared imaging from the 2MASS survey and optical spectra from the 6dFGS. These observational data are complemented by mock group catalogues generated from the latest ΓCDM simulations with gas physics included. Existing GEMS publications are briefly highlighted as are future publication plans.

An N-body code containing live stellar evolution through combination of the software packages nbody6 and stars is presented. Operational details of the two codes are outlined and the changes that have been made to combine them discussed. We have computed the evolution of clusters of 104 stars using the combined code and we compare the results with those obtained using nbody6 and the synthetic stellar evolution code sse. We find that, providing the physics package within stars is set up correctly to match the parameters of the models used to construct sse, the results are very similar. This provides a good indication that the new code is working well. We also demonstrate how this physics can be changed simply in the new code with convective overshooting as an example. Similar changes in sse would require considerable reworking of the model fits. We conclude by outlining proposed future development of the code to include more complete models of single stars and binary star systems.

The true nature of dark matter in the universe still eludes us. This paper discusses a new test for the detection of stellar mass compact dark matter in galaxy clusters by observing its gravitational lensing influence on the surface brightness of giant luminous arcs. If dark matter is in the form of stellar mass compact objects, then the extremes of such variability are accessible to a monitoring campaign with the Hubble Space Telescope. With the advent of the Next Generation Space Telescope, cluster dark matter in the form of compact objects will induce a ubiquitous ‘shimmering’ of the giant arcs.

The effect of nonaxisymmetric radiation drag on relativistic jets in active galactic nuclei (AGN) is discussed. The radiation force due to inverse Compton scattering of photon fields from a noncircular accretion disk is calculated. It is shown that such nonaxisymmetric drag can cause jet path distortion within the subparsec region of the black hole. This subparsec scale distortion is potentially observable with the current VLBI, VLBA techniques. Any modulation of the axially asymmetric distribution of disk emission can result in variability in electromagnetic radiation from the jet.

At 12:56 p.m., on Monday 21 July 1969 (AEST), six hundred million people witnessed Neil Armstrong's historic first steps on the Moon through television pictures transmitted to Earth from the lunar module, Eagle. Three tracking stations were receiving the signals simultaneously. They were the CSIRO's Parkes Radio Telescope, the Honeysuckle Creek tracking station near Canberra, and NASA's Goldstone station in California. During the first nine minutes of the broadcast, NASA alternated between the signals being received by the three stations. When they switched to the Parkes pictures, they were of such superior quality that NASA remained with them for the rest of the 2-hour moonwalk. The television pictures from Parkes were received under extremely trying and dangerous conditions. A violent squall struck the telescope on the day of the historic moonwalk. The telescope was buffeted by strong winds that swayed the support tower and threatened the integrity of the telescope structure. Fortunately, cool heads prevailed and as Aldrin activated the TV camera, the Moon rose into the field-of-view of the Parkes telescope. This report endeavours to explain the circumstances of the Parkes Observatory's support of the Apollo 11 mission, and how it came to be involved in the historic enterprise.

Kodak Technical Pan (Tech Pan) emulsion on a film base has been in use at the UK Schmidt Telescope (UKST) since 1992. This material is extremely fine grained and its resolution is well matched to images produced by the UKST under good conditions. Tech Pan yields wide-angle photographs that are about 1 (stellar) magnitude fainter than equivalent IIIa-F plates but have considerably lower grain noise. A wide variety of new projects are under way which take advantage of this remarkable material. In this paper empirical results from experiments with Tech Pan from a number of sources are tied in with UKST experience to present an overview of the properties of the emulsion from an astronomical perspective. We compare Tech Pan's properties with those of equivalent IIIa-F emulsion, to which it seems superior in almost every respect. This overview and groundwork are currently missing from the published astronomical literature. The technical background and developments leading to adoption of this material at the UKST are presented.

The rare carbonaceous chondrite which fell around the township of Murchison in northern Victoria, Australia, in 1969 has probably been the subject of more scientific publications than any other meteorite. The discovery of grains formed in a presolar environment and the abundance of organic molecules within the Murchison meteorite have facilitated studies of the formation of the Solar System, the development of stars and the origins of life.

The Australia Telescope Compact Array (ATCA) has been used to determine positions for many southern methanol maser sites, with accuracy better than 1 arcsec. The results are presented here as a catalogue of more than 350 distinct sites, some of them new discoveries, and many others with positional precision 10-times better than existing published values. Clusters of 2 or 3 sites are occasionally found to account for single previously listed sources. This in turn reveals that the velocity range for each individual site is sometimes smaller than that of the originally tabulated (blended) source. Only a handful of examples then remain with a velocity range of more than 16 km s−1 at a single compact (less than 2 arcsec) site. The precise methanol positions now allow apparent coincidences with OH masers to be confidently accepted or rejected; this has led to the important conclusion that, where a 1665-MHz OH maser lies in a massive star formation region, at more than 80 percent of the OH sites there is a precisely coincident methanol maser. The methanol precision achieved here will also allow clear comparisons with likely associated IR sources when the next generation of far-IR surveys produce precise positions.

In this contribution Gemini-North NIRI J,K-observations are used to investigate the upper-Asymptotic Giant Branch (AGB) intermediate-age population in the M81 Group dwarf elliptical (dE) F8D1. Hubble Space Telescope (HST) ‘snapshot’ V,I-observations are also analysed to investigate the upper-AGB populations in two other M81 Group dEs, DDO 71 and kk077. In all three dEs, significant intermediate-age populations are found. Further, there are sizeable dE-to-dE differences in these populations: F8D1 contains relatively more, and relatively more luminous, upper-AGB stars. These results are compared with existing information for Local Group and Sculptor group dwarfs. It is suggested that ‘environmental harrassment’ plays an important role in governing dwarf galaxy evolution.

A brief overview of the current radio source host galaxy state of affairs is given. All the evidence appears to point towards a scenario in which the young radio source expands through the host galaxy on timescales of 105–106 yr, before it ends its life as a large scale FR II radio galaxy. The place and role of the quasars in this evolutionary picture is unclear, however, and remains an issue of debate.

We describe a major Anglo-Australian project to undertake a UKST Ha survey of the Southern Galactic plane, Magellanic clouds and selected regions. The survey will use a new 12 × 12 inch monolithic Hα interference filter of high specification and Tech Pan film which offers significant advantages over other emulsions due to its peak sensitivity at Ha and its extremely fine grain, high resolution, exceptional DQE, excellent imaging and low noise. A survey of unprecedented area coverage, depth and resolution should result, superior to any previous optical survey of ionised gas in the galaxy. It is certain to lead to exciting new discoveries and new avenues of research.