NASA’s all-sky survey mission, the Transiting Exoplanet Survey Satellite (TESS), is specifically engineered to detect exoplanets that transit bright stars. Thus far, TESS has successfully identified approximately 400 transiting exoplanets, in addition to roughly 6 000 candidate exoplanets pending confirmation. In this study, we present the results of our ongoing project, the Validation of Transiting Exoplanets using Statistical Tools (VaTEST). Our dedicated effort is focused on the confirmation and characterisation of new exoplanets through the application of statistical validation tools. Through a combination of ground-based telescope data, high-resolution imaging, and the utilisation of the statistical validation tool known as TRICERATOPS, we have successfully discovered eight potential super-Earths. These planets bear the designations: TOI-238b (1.61$^{+0.09} _{-0.10}$ R$_\oplus$), TOI-771b (1.42$^{+0.11} _{-0.09}$ R$_\oplus$), TOI-871b (1.66$^{+0.11} _{-0.11}$ R$_\oplus$), TOI-1467b (1.83$^{+0.16} _{-0.15}$ R$_\oplus$), TOI-1739b (1.69$^{+0.10} _{-0.08}$ R$_\oplus$), TOI-2068b (1.82$^{+0.16} _{-0.15}$ R$_\oplus$), TOI-4559b (1.42$^{+0.13} _{-0.11}$ R$_\oplus$), and TOI-5799b (1.62$^{+0.19} _{-0.13}$ R$_\oplus$). Among all these planets, six of them fall within the region known as ‘keystone planets’, which makes them particularly interesting for study. Based on the location of TOI-771b and TOI-4559b below the radius valley we characterised them as likely super-Earths, though radial velocity mass measurements for these planets will provide more details about their characterisation. It is noteworthy that planets within the size range investigated herein are absent from our own solar system, making their study crucial for gaining insights into the evolutionary stages between Earth and Neptune.

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.

The most recent helium abundance determinations in main sequence B stars are those of Hardrop and Scholtz, Kodaira and Scholtz, Norris, and Leckrone. Their results indicate that it is possible to assign a helium abundance which is characteristic of all B stars. Norris and Leckrone worked with a number of B stars ranging from B0 to B9, and both have assigned a characteristic helium abundance to the B stars. Norris derived a value, A = 0.088 ± 0.012, and Leckrone a value of A = 0.106 ± 0.01, where A is the abundance of helium relative to hydrogen by number.

We present VLA 21-cm observations of the spiral galaxy ESO 481-G017 to determine the nature of remote star formation traced by an Hii region found 43 kpc and ∼800 km s−1 from the galaxy center (in projection). ESO 481-G017 is found to have a 120 kpc Hi disk with a mass of 1.2 × 1010M⊙ and UV GALEX images reveal spiral arms extending into the gaseous disk. Two dwarf galaxies with Hi masses close to 108M⊙ are detected at distances of ∼200 kpc from ESO 481-G017 and a Hi cloud with a mass of 6 × 107M⊙ is found near the position and velocity of the remote Hii region. The Hii region is somewhat offset from the Hi cloud spatially and there is no link to ESO 481-G017 or the dwarf galaxies. We consider several scenarios for the origin of the cloud and Hii region and find the most likely is a dwarf galaxy that is undergoing ram pressure stripping. The Hi mass of the cloud and Hi luminosity of the Hii region (1038.1 erg s−1) are consistent with dwarf galaxy properties, and the stripping can trigger the star formation as well as push the gas away from the stars.

In recent years, formal astronomy education has become an issue of great interest. Indeed, some boards of education now officially include astronomy in their curricula. While formal astronomy education continues to gain attention, informal astronomy education for the general public has rarely been addressed. One valuable source of informal astronomy education is the observatory ‘visitor centre’. Observatories draw thousands of visitors each year, and as such represent a golden opportunity for the astronomical community to communicate directly with the public. This paper summarises an exploratory study of the cognitive and affective impacts of a visit to the visitor centres located at Mount Stromlo and Siding Spring Observatories.

The Sloan Digital Sky Survey has been immensely successful in detecting new Milky Way satellite galaxies over the past seven years. It was instrumental in finding examples of the least luminous galaxies we know in the Universe, uncovering apparent inconsistencies between cold dark matter theory and dwarf galaxy properties, providing first evidence for a possible lower mass limit for dark matter halos in visible galaxies, and reopening the discussion about the building block scenario for the Milky Way halo. Nonetheless, these results are still drawn only from a relatively small number of galaxies distributed over an area covering about 29% of the sky, which leaves us currently with more questions than answers. The study of these extreme stellar systems is a multi-parameter problem: ages, metallicities, star formation histories, dark matter contents, population fractions and spatial distributions must be determined. Progress in the field is discussed and attention drawn to some of the limitations that currently hamper our ability to fully understand the phenomenon of the ‘ultra-faint dwarf galaxy’. In this context, the Stromlo Milky Way Satellite Survey represents a new initiative to systematically search and scrutinize optically elusive Milky Way satellite galaxies in the Southern hemisphere. In doing so, the program aims at investigating some of the challenging questions in stellar evolution, galaxy formation and near-field cosmology.

In conjunction with the Australian Government's Spectrum Management Agency, experimental tests have been carried out to determine the susceptibility of the Molonglo Observatory Synthesis Telescope (MOST) to interference from terrestrial transmitters. The motivation for the tests was to reconcile the conflicting requirements of the MOST, which is committed to an extensive survey of the southern sky at 843 MHz, with the commercial use of the 825–845 MHz band, which is being prepared for sale. The tests show that the far sidelobe gain of the MOST, relative to an isotropic antenna is generally less than 1, and that an appropriate interference criterion would be that in-band interference irradiance should not exceed −173 dBWm−2. This value is similar to that considered by the International Telecommunications Union to be detrimental to radio astronomy continuum observations at nearby frequencies.

The unprecedented imaging power of James Webb Space Telescope (JWST) provides new abilities to observe the shapes of objects in the early Universe in a way that has not been possible before. Recently, JWST acquired a deep field image inside the same field imaged in the past as the Hubble Space Telescope (HST) Ultra Deep Field. Computer-based quantitative analysis of spiral galaxies in that field shows that among 34 galaxies for which their rotation of direction can be determined by the shapes of the arms, 24 rotate clockwise, and just 10 rotate counterclockwise. The one-tailed binomial distribution probability to have asymmetry equal or stronger than the observed asymmetry by chance is $\sim$0.012. While the analysis is limited by the small size of the data, the observed asymmetry is aligned with all relevant previous large-scale analyses from all premier digital sky surveys, all show a higher number of galaxies rotating clockwise in that part of the sky, and the magnitude of the asymmetry increases as the redshift gets higher. This paper also provides data and analysis to reproduce previous experiments suggesting that the distribution of galaxy rotation in the Universe is random, to show that the exact same data used in these studies in fact show non-random distribution, and in excellent agreement with the results shown here. These findings reinforce consideration of the possibility that the directions of rotation of spiral galaxies as observed from Earth are not necessarily randomly distributed. The explanation can be related to the large-scale structure of the Universe, but can also be related to a possible anomaly in the physics of galaxy rotation.

We report the discovery of a bow-shock pulsar wind nebula (PWN), named Potoroo, and the detection of a young pulsar J1638$-$4713 that powers the nebula. We present a radio continuum study of the PWN based on 20-cm observations obtained from the Australian Square Kilometre Array Pathfinder (ASKAP) and MeerKAT. PSR J1638$-$4713 was identified using Parkes radio telescope observations at frequencies above 3 GHz. The pulsar has the second-highest dispersion measure of all known radio pulsars (1 553 pc cm$^{-3}$), a spin period of 65.74 ms and a spin-down luminosity of $\dot{E}=6.1\times10^{36}$ erg s$^{-1}$. The PWN has a cometary morphology and one of the greatest projected lengths among all the observed pulsar radio tails, measuring over 21 pc for an assumed distance of 10 kpc. The remarkably long tail and atypically steep radio spectral index are attributed to the interplay of a supernova reverse shock and the PWN. The originating supernova remnant is not known so far. We estimated the pulsar kick velocity to be in the range of 1 000–2 000 km s$^{-1}$ for ages between 23 and 10 kyr. The X-ray counterpart found in Chandra data, CXOU J163802.6$-$471358, shows the same tail morphology as the radio source but is shorter by a factor of 10. The peak of the X-ray emission is offset from the peak of the radio total intensity (Stokes $\rm I$) emission by approximately 4.7$^{\prime\prime}$, but coincides well with circularly polarised (Stokes $\rm V$) emission. No infrared counterpart was found.

A description of the production of astronomical speckles is given in terms of elementary physical principles. Using simple probability arguments, estimâtes are made of signal-to-noise requirements and magnitude limits for détection; data réduction techniques are discussed. A speckle System used on the AAT (Anglo-Australian Télescope) with the IPCS as detector is described.

The three objects Tau X−1, Cyg X−l and GX3+1 are the most prominent discrete X-ray objects in the sky at photon energies of ≃ 100 keV.

A combined multi-station radar equipment of c.w. and pulse at 27 MHz was used at Adelaide (lat. 35°S) during the period December 1968 to June 1969 and again in October 1969 to measure radiants and velocities of individual meteors down to limiting radio magnitude MR = + 8. Reflections from 3 to 5 points typically separated by 2 to 6 km along each trail were used and corrections for the effects of meteor region winds and wind shears were included. To date 1667 orbits have been determined from 6 months of data.

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).

Soft X-ray photographs of the Sun taken from the manned Skylab satellite (Vaiana et al. 1973) gave, not the earliest, but perhaps the most graphic evidence that the solar corona is patchy. During the Skylab mission (May 1973 to February 1974), the solar corona as usually envisaged covered only 80% of the Sun (Bohlin 1977). The areas lacking a ‘dense’ corona are called coronal holes (Withbroe al. 1971; Waldmeier 1975).

This review is concerned mainly with the solar modulation of galactic cosmic rays and the progress that has been made since the Tenth International Conference on Cosmic Rays (Calgary, June 1967), My aim is to set out some of the advances in the basic theories; to indicate why certain disagreements between convection-diffusion theory and observations (noted in Webber’s invited review at Calgary) are to be expected; and to indicate some of the currently emerging areas of interest.

Many of the X-ray pulsars for which X-ray lightcurves have been presented in the literature exhibit asymmetric emission beams. We postulate the existence of an off-centre magnetic dipole field embedded in the rotating neutron star and show that such a field leads to varying rates of matter transfer between an accretion dise and the neutron star surface, over a rotation period. Assuming that the accretion rate onto the surface is simply related to the luminosity, we show that most of the observed asymmetries can be accounted for by this mechanism.

The Physics Department at the University of Otago, Dunedin, New Zealand, has over the past three years commenced a research and teaching programme in astronomy and astrophysics. Observing facilities now include two metric wave meridian transit telescopes at a site 6 km from Dunedin and a 16-inch optical telescope, formerly at Mt John, which is now sited 4 km from Dunedin at the Signal Hill observatory built by the University’s Surveying Department for geodetic work.

In this article I review our understanding of s-process nucleosynthesis in Asymptotic Giant Branch (AGB) stars. The discussion begins with the nuclear back~ ground and then shows how the required conditions are found in thermally pulsing AGB stars. The two competing neutron sources (Ne22 and C13) are discussed, as is the observational and theoretical evidence for and against each of them. We conclude by discussing the recent evidence for hot bottom burning, including the observed enhancements of Li7 and Al26 in some AGB stars.

Radio maps of extragalactic radio sources made with the Westerbork, Cambridge and V.L.A. synthesis telescopes have revealed collimated jets extending from the cores to the radio lobes (see Miley 1980 for a review). These observations have provided outstanding support for ‘beam models’ of extragalactic radio sources (Scheuer 1974, Blandford and Rees 1974). Two crucial pieces of information to emerge from high resolution observations are the behaviours of jet full width half maximum (FWHM) and surface brightness with angular distance from the core. Such data have for instance been provided by Formalont et al. (1980) and Bridle et al. (1981) for the jets in 3C-31 and by Willis et al. (1981) and Bridle (1981) for the jets in NGC 315. An important point is that the relationship between jet surface brightness and FWHM is not in general as predicted by simple magnetohydrodynamic models (Bridle 1981).

Ina recent paper, Lockwood et al. (1991) have used IMP spacecraft and Neutron Monitor data to consider the rigidity dependence of three large Forbush Decreases over the energy range 50 MeV to 30 GeV. Some of their conclusions are extrapolated to higher energies.

In an earlier paper (Duldig, 1987a), one of us discussed the need to consider the presence of isotropic intensity waves when determining the Forbush Decrease spectrum at energies up to a few hundred GeV. Lockwood et al.’s conclusions are discussed in the light of these results.