We discuss the production sites of the nuclei from C to Al in solar metallicity stars in the range 13–35 M⊙. We will show how, contrary to current beliefs, the advanced burning phases and the passage of the blast wave play a pivotal role in determining the final yields of quite a few ‘light’ nuclei. We will also show how the relative contributions of the hydrostatic and explosive burning depend on the initial mass of the star: the smaller the mass the larger the importance of the explosive burning.

We compare observations of a large coronal streamer made with the 80 MHz Culgoora radioheliograph, the Kcoronameter on Mauna Loa and the white light coronagraph on Skylab. The various measurements are not in agreement, and this raises fundamental questions about the nature of the corona and wave propagation through a streamer structure. The comparisons also indicate how precise data from the heliograph may contribute to a better understanding of these processes.

Until early in 1968 radio sources were believed to be relatively constant and slowly evolving objects. Sporadic intensity variations had been found at high frequencies in some quasars but, except for the Sun and some flare stars which exhibited occasional bursts of radiation, the time scale of changing emission appeared to be very long.

Ammonia was the first interstellar molecule with more than two atoms to be discovered (Cheung et al. 1968). Since that time it has been observed in many HII regions and dark clouds (Mayer et al. 1973; Morris et al. 1973; Cheung et al. 1973; Kaifu et al. 1975). The molecule has a rich rotation-inversion spectrum with about 10 transitions in the range 23-25 GHz. Each line has hyperfine structure which permits, in principle, the determination of optical depths, filling factors and excitation. Unfortunately line brightness temperatures are low (<1 K) so that a low-noise receiving system and long integration times are required to exploit these possibilities.

The term ‘moving Type IV’ denotes a spectacular class of solar event in which the radio source, beginning low in the corona, moves outward, typically at hundreds of kilometres per second (Wild et al. 1963).

Radio snapshot imaging is an efficient observing method which allows several sources to be observed in the one session. Snapshot observing with the Australia Telescope Compact Array (ATCA) involves special difficulties, as the small number of antennas combined with the short total integration time leads to high sidelobe levels in the raw images. The images can be improved markedly by standard deconvolution techniques, but more care is required in their use because of the difficulty in distinguishing real emission from artefacts. This study, based on a set of snapshot observations of strong sources at 5 GHz, gives guidance on both the planning of observations and the data reduction. We show that snapshot imaging with the 6 km ATCA can achieve a dynamic range of 100–200:1 provided certain conditions are met, namely a peak flux density > 100 mJy, an angular size ≤ 30″ and an hour-angle coverage spanning at least six well-separated 5-minute cuts. When observing weak sources it is essential for calibration sources to be selected carefully and observed frequently.

During routine monitoring of active-chromosphere stars in August 1987 an intense radio flare on the FK Comae star HD 32918 was detected by the Parkes radiotelescope. Other observatories were notified, enabling data to be collected at 843 MHz, 1.4 GHz, 8.4 GHz and optical frequencies.

The flare at radio frequencies was largely similar to a previous event on this star, reaching a peak radio power of 5 < 1012 W Hz−1 at 8.4 GHz. During the flare the spectrum varied as ∼ v1.4 and later flattened as the flare progressed. Compared to the previous flare, circular polarization was higher.

Ca II and Hα optical spectra taken at the AAO 3.9-metre telescope show the star to have a highly active chromosphere and a strong wind, with a terminal velocity of ≈230 km s−1. While much of this activity appears to be long lived, there is good evidence for an increase in the strength of the chromospheric lines during the radio flare event.

Superluminous supernovae are beginning to be discovered at redshifts as early as the epoch of reionisation. A number of candidate mechanisms is reviewed, together with the discovery programmes.

While amongst the most luminous objects in the universe, many details regarding the inner structure of quasars remain unknown. One such area is the mechanism promoting increased polarisation in the broad absorption line troughs of certain quasars. This study shows how microlensing can be used to differentiate between two popular models that explain such polarisation through a realistic computational analysis. By examining a statistical ensemble of correlation data between two observables (namely image brightness and polarisation of the flux coming from the quasar), it was found that through spectropolarimetric monitoring it would be possible to discern between a model with an external scattering region and a model without one.

The Kunlun Infrared Sky Survey will be the first comprehensive exploration of the time varying Universe in the infrared. A key feature in optimising the scientific yield of this ambitious research programme is the choice of the survey passband. In particular, the survey aims to maximally exploit the unique thermal and atmospheric conditions pertaining to the high Antarctic site. By simulating the expected signal-to-noise for varying filter properties within the so-called ‘K DARK’ 2.4 μm window, filter performance can be tuned and best-case designs are given covering a range of conditions.

The very high fraction of C-enriched stars among the low end of the Galactic-halo metallicity distribution, along with the wide variety in content of their neutron-capture elements, make the understanding of their formation scenario(s) of extreme interest. The combination of accurate determinations of their chemical composition with long-term radial-velocity monitoring is crucial to address this issue. We discuss the first results of long-term radial-velocity monitoring for C-enhanced, metal-poor stars and explore the connection with chemical peculiarities; the data suggest that belonging to a close binary affects nucleosynthesis on the Asymptotic Giant Branch. We also present abundances for the poorly studied element fluorine in a sample of 10 C-enhanced stars with metallicities ranging from [Fe/H] = –1.3 to –2.9 and compare our measurements to the predictions of state-of-the-art nucleosynthesis models. We show how the observed abundances of fluorine in CEMP stars are considerable lower than expected on the basis of the current state-of-the-art theoretical calculations, hinting at our poor understanding of the nucleosynthetic processes that produce this element.

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 distant (redshift >1) Universe, that have been identified as key science drivers for the PILOT facility. The potential for PILOT to detect the first populations of stars to form in the early Universe, via infrared projects searching for pair-instability supernovae and gamma-ray burst afterglows, is investigated. Two projects are proposed to examine the assembly and evolution of structure in the Universe: an infrared survey searching for the first evolved galaxies at high redshift, and an optical survey aimed at characterising moderate-redshift galaxy clusters. Finally, a large-area weak-lensing survey and a program to obtain supernova infrared light-curves are proposed to examine the nature and evolution of dark energy and dark matter.

We use the SPace Infrared telescope for Cosmology and Astrophysics (SPICA) project as a template to demonstrate how deep spectrophotometric surveys covering large cosmological volumes over extended fields (1– $15\, \rm{deg^2}$ ) with a mid-IR imaging spectrometer (17– $36\, \rm{\rm{\upmu m}}$ ) in conjunction with deep $70\, \rm{\rm{\upmu m}}$ photometry with a far-IR camera, at wavelengths which are not affected by dust extinction can answer the most crucial questions in current galaxy evolution studies. A SPICA-like mission will be able for the first time to provide an unobscured three-dimensional (3D, i.e. x, y, and redshift z) view of galaxy evolution back to an age of the universe of less than $\sim$ 2 Gyrs, in the mid-IR rest frame. This survey strategy will produce a full census of the Star Formation Rate (SFR) in the universe, using polycyclic aromatic hydrocarbons (PAH) bands and fine-structure ionic lines, reaching the characteristic knee of the galaxy luminosity function, where the bulk of the population is distributed, at any redshift up to $z \sim 3.5$ . Deep follow-up pointed spectroscopic observations with grating spectrometers onboard the satellite, across the full IR spectral range (17– $210\, \rm{\rm{\upmu m}}$ ), would simultaneously measure Black Hole Accretion Rate (BHAR), from high-ionisation fine-structure lines, and SFR, from PAH and low- to mid-ionisation lines in thousands of galaxies from solar to low metallicities, down to the knee of their luminosity functions. The analysis of the resulting atlas of IR spectra will reveal the physical processes at play in evolving galaxies across cosmic time, especially its heavily dust-embedded phase during the activity peak at the cosmic noon ( $z \sim 1$ –3), through IR emission lines and features that are insensitive to the dust obscuration.

Australian astronomers have a proud history of comet-discovery, beginning with Rumker of Parramatta Observatory in 1824 (Baracchi 1914), and culminating with the outstanding achievements of Bill Bradfield of Adelaide. In the intervening one hundred and fifty years there have been a number of other notable comet-hunters and comet-observers, the most successful being John Tebbutt (see Orchiston 1981, 1982a, 1982b), Walter Gale, David Ross, and J. F. Skjellerup. Comets discovered by these Australian astronomers, and others, are listed in Marsden’s 1982 Catalogue of Cometary Orbits.

The major programs at the Molonglo Radio Observatory are nearing completion. Much can still be done using the existing 1 mile Cross-type radio-telescope (Mills et al. 1963) but, to tackle properly many of the current problems in radio astronomy, a fundamental change is required from a transit to a trackable radio-telescope, combined with an increase in the operating frequency and the resolution.

From an assessment of recent high-resolution galactic radio surveys, in the continuum and in the H109oc recombination line, the author has detected or confirmed over 90 non-thermal sources, most likely all supernova remnants.1 The distances to each of these objects have also been estimated, from an empirical surface-brightness linear-size relationship derived from 15 remnants whose distances are known from either a comparison of the radial velocities and proper motions of filaments in the nebula, neutral hydrogen absorption measurements, or association of the remnant with an object of known distance. In this note we wish to remark on the galactic distribution of supernova remnants and the possible association of these objects with pulsars and X-ray sources.

From early experiments in 1966 (Cole 1968) the acousto-optical radio spectrograph has been developed at CSIRO to a sensitive, multi-channel spectral-line back-end. The principles of the instrument are described in detail elsewhere (Lambert 1962; Hecht 1977; Milne and Cole 1977). By means of a Bragg interaction between a laser beam and an ultrasonic beam derived from the radio signal, light is diffracted into an order whose light intensity distribution is accurately related to the power spectrum of the radio signal. In the earlier spectrographs the spectrum was recorded photographically (Cole 1973a, b; Hecht 1973) but this was limited to strong spectral features. To study weak spectral features a stable, linear system was needed with large dynamic range. The combination of an array of photodiodes and computer would be capable of observing these weak spectral features (Cole and Abies 1974). Development since 1974 has been a progressive identification of sources of thermal and mechanical instability and of excess noise in the spectrograph system.

Radio contours are presented for Fornax A (NGC 1316), Virgo A (NGC 4486) and the central component of Centaurus A (NGC 5128). These three objects are intrinsically strong radio emitters identified with bright galaxies. The work forms part of a survey of all bright galaxies with the Molonglo cross down to a corrected total magnitude of 11m.0 with an extension down to photographic magnitude 12m.5 in an limited region of the sky.

Radio pictures of the Sun from the Culgoora radioheliograph have already shown instances in which flares have initiated radio bursts in parts of the Sun remote from the flare position. In this paper we discuss two such events on 1968 May 4 and May 6, in each of which it appears that shock-waves arising from a flare produced distant prominence activity which led to the generation of metre-wave continuum radiation.

The magnetic structure in the source region of a type II burst and along the path of the type II disturbance has remained an enigma despite over 20 years of radio observations of the Sun (see e.g. reviews by Wild and Smerd (1972) and McLean (1974)). This paper describes the first radioheliograph observations of a type II burst near coronal magnetic structures depicted by soft X-ray pictures. It will be shown that three separate lanes in a type II burst are associated with three separate source regions each located almost radially above a soft X-ray loop. To explain these observations a model is derived in which a wide-fronted m.h.d. disturbance travels from the flare explosion along magnetic field lines and then intersects successively with three coronal streamer structures each located above a soft X-ray loop. An estimate of the magnetic flux density along the soft X-ray loops is obtained from the velocity of the m.h.d. disturbance.