Radio astronomy software has not quite kept up with recent developments for the display of, and interaction with, data. At the Australia Telescope National Facility we are trying to catch up by investigating how useful visualisation techniques and approaches like visual computing are for the reduction of radio data. I will discuss a few techniques that we have applied to radio data and comment briefly on their merits.

The effects of including low quality IRAS flux data in colour-colour diagrams is investigated, with a view to identifying Young Stellar Objects from the IRAS database. Colour criteria to perform this task are derived.

Ground-based observations of Type III bursts made with spectrographs and spectro-polarimeters, at frequencies above the ionospheric cut-off, reveal that most bursts (excluding storm Type IIIs) have fundamental (F) and harmonic (H) structure (Wild et al. 1959; Dulk and Suzuki 1980). An example of F-H bursts is given by Sheridan (1978). Such bursts are produced by streams of electrons travelling along open magnetic field lines and exciting plasma oscillations which are converted to electro-magnetic waves at both the F and H frequencies of the local plasma frequency in the corona.

In May 1984 site testing began for the Automated Patrol Telescope. A series of atmospheric extinction and night sky brightness measurements were made over the following year at Parkes and Siding Spring Mountain using B and V filters. Parkes revealed an extinction greater than that of Siding Spring and more prone to variation. Results for the night sky brightness indicated Parkes has a sky slightly brighter than that at Siding Spring. The paper discusses the procedures used for obtaining the results and their limitations.

Two important problems have emerged from observations of 18 cm OH emission sources that remain substantially unanswered by existing theories. The first is the problem of the origin of the high degree of circular polarization that is frequently observed. The second is what I have called the ‘problem of variety’: is it necessary to invoke a number of different physical mechanisms to explain the variety of qualitatively different behaviours observed, or can these different behaviours be explained by variations of one basic physical process?

Important observations of X-ray sources and searches for the optical counterparts of X-ray and radio pulsars require a capability of detecting and analysing light variations with a time scale of milliseconds. X-ray sources in binary star systems are expected to be collapsed objects – neutron stars or black holes (Peterson 1973) – and are expected to produce light variations. In the case of a neutron star, pulses with the same period as the rotation period of the neutron star would be produced, and such have been observed from Cen X-3 (schreier et al. 1972) in the X-ray, and from Her X-1 (Middleditch and Nelson 1973) and the Crab Nebula pulsar (Cocke et al. 1969) in the X-ray optical.

Spectropolarimetric observations of the 10 arc second region surrounding Eta Carinae have been made in the 8-13 μm wavelength band. The observed polarization, of a few percent, is due to emission of radiation from aligned grains. The radial position angle of the polarization suggests that gas streaming is responsible for the grain alignment.

More than 1000 coefficients of atmospheric extinction in the U, B and V passbands were obtained as a secondary result of long-term photometric monitoring of stellar objects at Yonsei University Observatory during 1982–1989. The long-term variation of the extinction coefficients of each passband are presented in this paper.

The detection of formaldehyde absorption of the microwave background radiation in a region of the Southern Coalsack (Sinclair and Brooks 1972) was made at about the same time as an optical study of this region (Tapia 1972) in which six globule-like clouds of interstellar dust were found. The size (0.3 pc) and position of the formaldehyde cloud were similar to the corresponding parameters of one of the globules (No. 2 on Tapia’s list).

The dynamics exhibited by systems, such as galaxies, are dominated by the isolating integrals of the motion. The most common are the energy and angular momentum integrals. The motions in a system with a full complement of isolating integrals are regular, that is, periodic or quasi-periodic. Such a system is integrable. If there is a deficiency in the number of integrals, then the motions are chaotic. There is a fundamental quantative difference in the motion, depending on the number of integrals. A technique, called Generalised Painlevé analysis, based on complex variable theory allows the user to determine if a system is integrable. Two new integrable cases of the Henon-Heiles system are presented, bringing the total number of such integrable potentials to five. It is highly probable that there are no further integrable cases of the Henon-Heiles potential. Five cases of the quartic Verhulst potential, defined by certain restrictions on the coefficients, which are found to be integrable are summarised.

Four tree ring-index site chronologies, representing standardised annual growth rates for spruce trees growing at high altitude sites in Colorado, have been employed as proxy data in a regression model for the annual variation of solar radio flux at 2800 MHz (F 10·7) and the Catania sunspot area (A c). These dendrochronological time series all exhibit significant power spectrum peaks at about 11 years and separately correlate with the annual values of R z, F 10·7 and A c, as solar activity indicators. The two models constructed give the cyclic variation of F 10·7 and A c back to AD1673.

Observational astronomy extends, in terms of energy in the electromagnetic spectrum, from below 10-8eV to above 108eV. Studies of cosmic rays extend this range to the neighbourhood of 1019eV (about a Joule) and the aspects of high energy astrophysics discussed in the present paper are those concerned with cosmic rays of energy upwards of about 1015eV.

The Llanherne telescope is a meridian transit instrument with an instantaneous bandwidth of two octaves in the range 35 to 150 MHz, and was constructed primarily for studying the low frequency properties of pulsars. The antenna is a 78 × 156 metre filled aperture phased array comprising 4096 wire dipole elements arranged in a 64 × 64 matrix. Uniform illumination of the elements produces a single pencil beam response which is scanned electronically along the meridian from Declination -90° to +30°. The beamwidth at 100 MHz is 1 degree in right ascension and two degrees sec(Dec.) in declination and varies proportionally with wavelength, giving a transit time of 4 sec(Dec) × 100/f(MHz) minutes between half power points.

The PKSCAT90 database consists of radio and optical data for 8264 radio sources. It covers all the sky south of declination +27 degrees. Most of the galactic plane and the Magellanic Cloud regions are excluded from this catalogue but have been the subject of other specialised surveys. A few data errors in the initial PKSCAT90 version 1.00 released in March 1990 have been corrected in the current version 1.01 edition.

Lin and Hudson (1976) have recently analysed non-thermal processes in proton flares, using observations of a series of major events in August 1972. They concluded that the 10–100 keV electrons accelerated during the flash phase account for the bulk of the total energy of a large proton flare (about 1032 – 1033 ergs); that most protons are accelerated later than the 10 — 100 keV electrons; and that most energetic protons escape to the interplanetary medium. Their conclusions with regard to proton acceleration are supported firstly by the delay of the maximum of γ-ray emission by 3-5 minutes after the maximum of X-ray emission, and secondly by the satisfactory agreement between the 7-ray spectrum and the thin-target model of emission. The energetic protons contain a very small fraction of the total flare energy (of the order of 10-5).

We report on an initial survey of the cores of the Rho Ophiuchus and R Coronae Australis clouds, made with the AAT’s new IR array camera, IRIS. No turnover is seen in the initial luminosity function for ρ Oph to the sensitivity limit of the survey. Some implications for the low mass end of the initial mass function are discussed.

Photo-electric observations of the occultation of BD —17°4388 by Neptune on 1968 April 7 were made with instruments and techniques as listed in Table I. A preliminary report of these observations has been given in IAU Circular No. 2067.

Six solar proton events have been observed by ground level cosmic ray detectors so far during solar cycle 21, a little less than one per year. All of these have been much smaller than the giant events observed in solar cycle 19. As with many other aspects of solar activity, the reason for the differences from cycle to cycle remain unknown.