The eclipsing variable SV Cen was observed differentially in the UBV system with the 60cm reflector at Perth Observatory (1974-75) and with the 41cm reflector at Siding Spring (1975-79). Individual measurements have either been published in the IBVS or will be published there soon.

DI Peg has been recognised as an eclipsing system since 1934 when Morgenroth (1934) discovered its variability. For over fifty years, many observers [Jensch (1934), Opalski (1936), Tsesevich (1954), Szafraniec (1956), Kruszewski (1956), Huth (1966), Rucinski (1967), Binnendijk (1973)], have studied this system. DI Peg was observed at Midway Observatory (M.O.) during 1976 and 1977 (Kennedy 1978). Considering the erratic period changes of the system, it appeared desirable to check the system again during 1980.

The discovery of the variability of the eclipsing system UX Eri can be attributed to Soloviev (1937). Photographic observations were made by Zessewitsch (1934, 1954), Bodokia (1938) and Gaposchkin (1953). Photoelectric observations were obtained by Kitamura and Nakamura (1957). The most recent photoelectric data were obtained by Binnendijk (1967) who determined new orbital elements. During the 10-year period from 1967-1977 the variable appears to have received little attention.

Guthnick and Prager (1929) were the discoverers of the variability of AH Virginis. Prager (1929) produced a photographic light curve the same year. Lause (1934, 1935, 1937) observed the system visually and improved the period as deduced by Prager. Further visual work on the system was done by Zessewitsch (1944). The first photoelectric observations came from Huruhata and Nakamura (1951), followed in 1952 by Kitamura, Tanabe and Nakamura (1957).

Lack of their data on ingress and egress at primary eclipse resulted in the mean curve showing a rounded bottom during minimum light. From this, an inclination of the system of 61° was derived by Kopal and Shapley (1956). Two years later, Kwee (1958) revealed primary minimum to be flat bottomed; the light remaining constant for some 40 minutes. This was confirmed by Binnendijk (1960), thus classifying AH Virginis as one of the few W UMa systems which display complete eclipses at an inclination likely to be closer to 90° then to 61°. Observations of the present study confirm constancy of light of 40 minutes duration during primary minimum. Assuming i = 90°, a new orbital solution was derived by Kitamura and Takahashi (1959) showing constant light for both minima. Binnendijk’s observation, however, showed a curved appearance at secondary minimum. The present observations indicate curved as well as flat secondary minima.

Since the discovery of the first asteroid by Piazzi in 1801, orbits have been determined for over 2500 with varying degrees of quality; 2357 have been assigned permanent numbers as of this writing (Marsden and Bardwell 1981).

The properties of the M dwarfs have been investigated by spectroscopic and photometric observations of over 150 red, high proper motion stars. Most of these stars have red magnitudes fainter than 12 magnitude.

An accurate determination of the global Hubble Constant needs distance to objects well outside the Local Supercluster with redshift greater than ~ 2000 km/s. This is mainly to reduce the effect of the peculiar motion of the Local Group on the measured redshifts as well as to get away from the gravitational influence of the nearby high density regions.

The present practice of deriving distances involves identifying objects such as Cepheids and brightest red stars both in the Local Group galaxies as well as in the distant galaxies. This method cannot be used for galaxies at the large distances.

The aim of this study is to investigate the spheroidal halo around our Galaxy, that is, the outer extentions of the central bulge. The kinematics and variations in metal abundance in the halo are important astrophysical parameters for any theory which models the formation and evolution of our galaxy. Attempts to determine these parameters have so far used a particular class of stars which can be easily identified as members of the halo.

The soft X-ray source HO 139-68 was originally detected with the low energy detectors of the HEAO A-2 experiment, and confirmed by later IPC observations (Agarwal et al. 1981). The X-ray observations show flux variations in the 0.15 – 0.4 keV band of a factor of two, or timescales of a few hours, with evidence for short time-scale flickering. Following communication of the source position to us by Agarwal and Riegler, we obtained time-resolved optical spectrophotometry of a star close to the X-ray position, using the IDPCA on the MSO 1.9m telescope. The spectrophotometry and later polarisation observations confirm the optical identification and that the source is an AM-Herculis type binary system, with a late type dwarf secondary overflowing its Roche lobe in a magnetically constrained funnel onto a magnetic white dwarf (WD) primary (Visvanathan and Pickles 1982).

We present 2.2 μm maps of four southern HII regions. Although each of these objects has been extensively studied at radio wavelengths with low spatial resolution, they have so far (with the exception of G333.6 – 0.2) received little attention in the infrared. As a first step towards understanding the structure of these objects we have therefore produced images of each in the K-band (2.2 μm) continuum.

There has been considerable speculation in recent years about the evolution of radio galaxies in clusters. The discovery of powerful X-ray emission with an apparently thermal spectrum from a considerable number of clusters has been attributed to a hot (108K) intracluster gas with an electron density of ∼ 10-3 cm -3 at the cluster centre (see e.g. McHardy 1978). Such a gas surrounding a radio galaxy may conceivably retard the expansion or diffusion of the relativistic electrons and thus allow the source to retain its identity for longer intervals than is the case for field galaxies.

The 4-m radio telescope of the CSIRO Division of Radiophysics at Epping is being used to survey the line emission associated with the 1→0 transition of CO (rest frequency 115.271 GHz) in the southern Milky Way. The programme includes mapping the CO distribution across giant molecular-cloud/HII-region complexes. As a first stage the emission has been observed towards bright southern HII regions. These results will not only serve as a basis for future extensive mapping but will also provide data which is directly comparable with observations of other molecular lines that have been made towards the HII regions.

Lynds 1642 is a small, somewhat insignificant dark cloud centred at 04h33, — 14°20 (1950). On a IIIaJ UKSTU Schmidt plate it may be seen to lie within an approximately circular patch of nebulosity which we believe to be visible by reflection. Its galactic location (l = 210°.9 b = -36°.5) places it beneath the local arm in the direction of Orion and it is likely that it is seen by reflection of the integrated light of the stars in that region of the galaxy.

The Corona Australis cometary globule is a large southern object known to be a region of slow star formation. We have mapped the complex in the 21cm hydrogen line and preliminary results are reported in Llewellyn et al. (1981) and Taylor et al. (1981). The most extensive A, map of the region is given by Rossano (1978) and is based on star counts.

The strong unidentified radio source 1733-565 (≡ PKS 1733-56) was chosen as a test source during the commissioning of the Molonglo Observatory Synthesis Telescope (MOST) in 1981 July. Previous radio maps have been obtained at 1410 MHz with the Parkes interferometer (Schwarz et al. 1974), at 408 MHz with the Molonglo Cross (Schilizzi & McAdam 1975) and at 1415 MHz with the Fleurs Synthesis Telescope (Christiansen et al. 1977).

A new maser receiver, operating between 20 and 24 GHz and constructed by the radiometer group at the CSIRO Division of Radiophysics, was first scheduled for astronomical observations in December 1981. In good observing conditions the system temperature was as low as 60 K. In conjunction with the versatility of the 1024-channel correlator and the large collecting area of the Parkes telescope (the central 37 m illuminated at 22 GHz yields a ratio of flux density to antenna temperature of 9∼ Jy K-1) the total system is a very powerful new tool. Here we report some observations of naturally occuring celestial H2O masers which we have studied with this system.

Our previous observations of the distribution of the H110α recombination line emission (rest frequency 4.87 GHz) towards Sgr A, obtained with the Parkes 64-m telescope and a 4′ .5 arc beam (Gardner and Whiteoak 1977 — to be referred to as Paper I), suggested that the emission was concentrated around the outer edge of the ‘arc’ of continuum radiation which extends 15′ arc to the north-east of the galactic nucleus.

The reason why some early-type galaxies contain powerful radio sources is not yet well understood, but it is often suggested that an external factor such as interaction with a neighbouring galaxy may be involved in triggering a radio source (Gisler 1976, Dressel 1981, Hummel 1981b). Radio emission may be enhanced in galaxies which have a close companion for several reasons, such as a gravitational perturbation or the possibility of gas accreted from the companion fuelling a central source. The latter effect might be expected to be more pronounced in elliptical galaxies, which are generally gas-poor (Faber and Gallagher 1976).

It is now firmly established that a small anisotropy of the galactic cosmic rays exists, observable from Earth as a variation of intensity in sidereal time. The problem now is to determine more clearly the characteristics of the anisotropy and, in particular, its detailed spatial structure and how it depends upon the energy and composition of the cosmic rays. This is a very difficult task and, in the final analysis, may not be fully achievable from Earth-based observations. The purpose of the present paper is to describe briefly an installation now operating in Tasmania to provide further information on the spatial structure of the anisotropy.

The first version of this mission was approved by the European Space Agency (ESA) Council in 1973 but did not infact start its Phase B study until 1977. The early baseline design had been constrained by the requirement to make the spacecraft compatible in size and weight with the performance of a NASA Delta rocket, since this was seen as a necessary back-up to Ariane, then at an early stage of development. The mission payload then evolved with time due to the changing role dictated by the technical successes and observations made by the series of well-known X-ray satellites. The final spacecraft has emerged to have a unique capability since all the other X-ray satellites except the small Hakucho have now expired.