The region of the solar atmosphere where the brightness temperature is less than 9 x 103 K. defines the photosphere and low chromosphere. In physical scale this covers the range from 300 km. below to 2 x 103 km. above the visible surface.

It is widely believed that stars form from collapsing interstellar clouds. However, molecular clouds typically contain of the order of 103 solar masses. Thus a mechanism is required that allows a collapsing cloud to fragment into a number of collapsing stellar sized sub-condensations. The early work was based on a virial theorem approach—defining a critical mass a cloud must exceed in order for its gravitational force to overcome the resistive thermal, rotational and magnetic forces, thus allowing the cloud to collapse. This critical mass is analogous to the Jeans mass for non-rotating, non-magnetic clouds. It is thought that a cloud containing several critical masses may collapse into several sub-condensations. Further, it is thought that the galactic magnetic field will cause the critical mass to decrease as the cloud collapses, allowing the cloud to fragment into a number of sub-condensations. The critical mass decreases as the cloud flattens down the field lines (since M crit ∝ B 3/ϱ 2 and B ∝ ϱk, K < ⅔ for non-isotropic collapse).

We present some preliminary results of an optical and radio study of the very active RS CVn binary HD 127535. Photometric measurements show the presence of a large amplitude wave which exhibits marked changes in shape and range on time scales as short as a few months. This photometric variation is almost certainly due to large cool starspots on the cooler, more luminous component. As part of a survey of southern active-chromosphere stars with the Parkes radio telescope, HD 127535 has been observed at 5, 8.4 and 22 GHz. No detection was made at 5 GHz, possibly because of confusion due to the angular proximity of the star to the galatic plane. However, it is one of the strongest sources detected in the 8.4 GHz survey, and is one of only two stars detected at 22 GHz. Photometry obtained two cycles before the 8.4 GHz observations suggest a possible correlation between the radio emission and the photometric wave, i.e. spot visibility, but more data are needed.

Charles Todd, who established the Adelaide Observatory on West Terrace in 1860, retired as Government Astronomer at the end of 1906. In 1908 the meteorological duties of the Observatory were taken over by the Commonwealth, and the Observatory lost most of its staff. Following the promotion of George Dodwell to the position of Government Astronomer in 1909, the Observatory was slowly re-established and undertook a range of astronomical and other work, which is described in detail in this paper. The Observatory was transferred to the University of Adelaide in 1940 and this is often taken as the closure of the Observatory. Dodwell finished working as Government Astronomer in 1952.

Figure 1 is a plot of spin angular momentum, J, against mass, m, for some of the main sequence stars, the planets and the asteroids.

In April 1967 the British and Australian Governments agreed jointly to build and operate a 150-inch (3.8m) optical telescope on Siding Spring Mountain, 16 miles west of Coonabarabran, N.S.W., where the Australian National University has an established observatory. To direct the construction and subsequent operation of the new telescope it was decided to create a statutory authority to be known as the Anglo-Australian Telescope Board. Pending the formation of this board, the two Governments, acting through the Department of Education and Science in Canberra and the Science Research Council in London, set up a joint policy committee to initiate the project.

It is the usual practice during continuum radio observations at Parkes to observe ‘pointing sources’ concurrently with the program objects.

The Molonglo Observatory Synthesis Telescope (MOST), operating at 843 MHz, is currently surveying the southern galactic plane (245° <l<360°, −1.5° ≤b≤ +1.5°). The resulting maps provide images of the radio continuum with a synthesised beamwidth of 43′′ × 43′′ cosec δ and a noise level of about 1mJy. The survey involves 12-hour synthesis observations of over four hundred fields on a predefined set of field centres. About half the fields have been observed to date, and the survey is scheduled for completion in 1990. A noteable feature in many of the fields is the occurrence of widespread diffuse filamentary structure, in addition to the expected supernova remants and HII regions.

Adult education classes in astronomy have been conducted in Sydney for many years. The University of Sydney has been especially prominent in this field, holding classes in conjunction with the Sydney WEA prior to 1983, and independently since then. In the last 11 years, most of these courses have been conducted by postgraduate students from the Astrophysics and Astronomy departments in the University’s School of Physics. This paper describes these courses and points out some future possibilities in the teaching of astronomy to adult classes.

To present-day astronomers the name of Robert Ellery, by which our newly established lectureship is to be known, means little. A century ago it was a different story. Ellery was then one of the most respected scientists in the country, a leading astronomer who had been director of the Melbourne Observatory since it was founded in 1853, and who had taken it to a prominent position in international astronomy. Besides this he was a man of parts who spread his talents widely. He was a founder and long-term president of the Royal Society of Victoria, treasurer of the University Council, chairman of the committee of the Alfred Hospital, Trustee of the Public Library, the Art Gallery and the Museum, and he was an active member, latterly commander, of the local Torpedo and Signal Corps, a coastal defence unit manned by citizen soldiers. Late in life he became the first president of the Beekeepers’ Club. He was elected to the Royal Society and awarded a CMG: all in all, a man of character and achievement.

Solar X-ray bursts observed by a proportional counter carried on the IMP-F satellite have been analysed for correlation with optical Hα flares and radio bursts. The solar X-ray flux at energies greater than 3 keV was measured each 82 seconds and consisted of impulsive bursts superimposed on a slowly varying X-ray background. During June and July 1967 there were an average of ~10 bursts per day with intensities greater than 400 photons cm−2 s−1 (2 × 10−6 erg cm−2 s−1) which was the threshold for observation of a burst.

Current results from the experiment by Reines et al (1980) on the oscillation of neutrinos from one flavour to another, if confirmed, require a non-zero rest-mass for the neutrino. Corroborative evidence can be adduced from the astrophysical consequences. In particular, the long-standing ‘missing light’ paradox in rich clusters of galaxies is solved (c.f. Cowsik and McClelland 1973), and more recent difficulties in reconciling the chronology of the Universe with both the primordial abundance of He4 and the cosmological mass density are eased (c.f. Symbalisty et al 1980). Finally Lewis (1981) shows that the concept also solves the problem of obtaining dynamically relaxed clusters of galaxies with feasable formation times. As a result, elliptical galaxies are necessarily formed from the material of a proto-cluster amid a high density of low-velocity neutrinos. This paper makes a preliminary estimate of the maximum neutrino content of elliptical galaxies.

Mount Stromlo Observatory came into being on 1 January 1924. First known as the Commonwealth Solar Observatory, it was founded primarily for studying the Sun and solar-terrestrial relations, though from the outset it was much concerned with various aspects of geophysics. There was also a stellar programme, but after a promising start this had to be discontinued. The solar-geophysical regime continued, with success, until World War II. The Observatory went through the War with a new director, and at the end of it embarked on a new and unfamiliar course to develop into the fully-fledged astrophysical institute it has become today. This transition marks an important chapter in the history of Australian astronomy: I have tried here to describe some of its aspects, as they seemed to me.

A version of this paper was originally presented at the Fifth National Space Engineering Symposium at Canberra in November 1989. A copy of the full paper will be found in the text of the Proceedings. It is presented here because the authors believe that the issues raised and strategies suggested are as relevant to the astronomical community as they are to other areas of space science and technology.

Properties of the microwave emission from HR1099 are examined in an attempt to determine whether the emission arises as gyro-synchrotron radiation from mildly relativistic electrons trapped in magnetic fields above starspots on the active K subgiant component. It is shown that radio curves do not exhibit a systematic variation in phase with the rotation rate, as one might expect for emission from a source situated above a long-lived starspot. However, there is some evidence that the radio flaring occurs at two preferred longitude zones. Whether these zones agree with starspot locations remains to be determined by light curve modelling. What we can say with confidence is that the measured spectral index of the microwave emission does not fit a simple gyro-synchrotron source model, such as that proposed to explain the observed reversal with frequency of the sense of circular polarization.

For a number of years the occurrence of isolated groups of apparently related type III bursts has been recognized as a common feature of the dynamic spectral records of solar radio emission at metre wavelengths. Interferometer observations supported the simple hypothesis that bursts of a group were usually located in the same position. In this note we report 80 MHz observations made with the Culgoora radioheliograph which show that although the sources of the bursts in a group tend to overlap one another, their centroids may show marked scatter and that their distribution tends to be along narrow lanes across the solar disk. Since the 80 MHz sources occur at heights (≳ 0.6 R⊙) near or above the plasma level, these lanes doubtless reflect some structural feature of the outer corona.