An HI survey of the Large Magellanic Cloud (LMC) has been reanalyzed to find the transverse velocity of the LMC, and derive an upper limit of 4.5 × 1011 M⊙ for the mass of our Galaxy out to 50 kpc. A rotation curve is derived for the LMC from the HI data giving a best mass estimate of (4.0±0.4)×109 M⊙. Velocity observations of 97 planetary nebulae (PN) in the Large Cloud are used to compare the old and young components. Our results are found to be at odds with an earlier sample of 9 old clusters, which is interpreted as being due to the low number of objects in that sample. The w-component of velocity dispersion of the PN population is 35 km s-1 and that of the HI 10 km s-1. If this difference is a result of stellar diffusion then the average age of the PN population is 1.3 × 109 yr, implying a precursor mass of 1.8 M⊙ and a remnant mass of 0.63 M⊙.

Symbiotic stars are at the same time perplexing and rewarding to study. Their spectra contain great numbers of emission lines due to atoms in a range of ionization states from neutral to coronal. The continua are weak and usually unobtrusive: the strongest lines may have equivalent widths of thousands of Angstroms. But the crowding of weak lines complicates their measurement and, often, their identification. Many symbiotic stars probably emit weak lines which currently defy identification, but which cannot be distinguished from their neighbours. It is, however, rather rare to find a strong unidentified emission line.

Mestel, Wang and Westfold (1984; ‘MWW’) have recently introduced a pulsar magnetosphere model in which electrons leave the star with non-negligible, but not highly-relativistic, speeds, and flow with moderate acceleration along magnetic field lines before reaching a limiting surface, near which rapid acceleration occurs. Such moderately accelerated flows are analysed here. A second class of flows, which do not encounter a region of rapid acceleration, is found.

The design of the Australia Telescope is discussed, particularly in reference to the compact array, the frequency ranges of operation, the field of view, dynamic range, polarization, bandwidth, correlators, time resolution and flexibility. Site preparation at Culgoora, antenna design, reflector panel construction, feed horns, receivers an cryogenics, and computing are receiving full attention.

A survey of the optical spectra of IRAS galaxies, made with the AAT, has shown that the majority have strong emission lines. Ratios of the emission lines have been plotted on the Veilleux-Osterbrock diagram ([O III]/Hβ against [N II]/Hα); this shows that the IRAS galaxies comprise several classes. In our sample the majority appear to be starburst galaxies, but Seyfert, Liner and narrow-line galaxies are also represented. Co-added spectra of the galaxy classes are presented. On the basis of optical spectroscopy, it appears that the starburst phenomenon is capable of generating luminosities exceeding 1012L⊙.

Pulsars may be born with a short rotation period of milliseconds with the magnetic field amplified through dynamo processes up to ∼1015–1016 G. Such millisecond magnetars spin down rapidly, emitting bursts of high-energy neutrinos and gamma rays. Specifically, acceleration of ions in both the polar gap (as in a normal pulsar) and the relativistic magnetar wind is considered. In both cases ions can be accelerated to ultra-high energies and these energetic ions can lead to production of high-energy neutrinos and gamma rays through interaction with thermal radiation from the hot neutron star or the heated inner boundary region of the stellar envelope as the result of the deposition of energy by the magnetar wind. The detectability of the neutrino flux by a kilometre-scale neutrino detector such as the planned IceCube neutrino observatory is discussed.

We present evidence for an anti-correlation between faint QSOs and B < 23 galaxies.A sample of 192 QSOs in a 2.5 deg2 area has been imaged using the Isaac Newton Telescope Wide-Field Camera. The cross-correlation signal is of a similar amplitude to the galaxy auto-correlation function at the limit of B < 23, but is negative in sign. As fainter galaxies are selected the negative correlation signal becomes less significant, until the signal is effectively zero at B < 26. We propose two alternate explanations for the observed effect. The first is gravitational lensing of the faint background QSOs, which have a flat number count slope. However, the lensing signal is significantly higher than expected in conventional models. The second possibility is that inter-galactic dust absorption is responsible. A reddening of only E(B - V) ≃ 0.02 is required to produce the observed correlation. The large 2dF and SDSS QSO surveys should allow a definitive solution to the question of QSO–galaxy correlations.

Digital images were made of Bamberg Observatory Sky Patrol plates of the field surrounding the active-chromosphere star CF Octantis (HD 196818). These images, taken with an inexpensive camera, were analysed using standard aperture photometry techniques. Good agreement was found with catalogued photographic magnitudes for stars in the range mpg ∼8.5 to ∼10.5. The root-mean-square deviations in the measured differences for non-variable field stars was found to be of order 0.10 mag, although a small number of larger differences occurred. For CF Oct, a period search of data from 1966 recovered the known 20 d variation due to starspot rotational modulation, with a range of variation of order 0.5 mag photographic. For active-chromosphere stars with moderately large photometric variations (>∼0.3 mag), and moderate to long rotation periods (>∼1 week), careful analysis of similarly obtained digital copies of archive plates may provide valuable insights into historical actvity.

The E. & F. White Conference held in Sydney in December 1999 brought together expertise on a range of interference mitigation techniques from CSIRO, Australian and international industry and universities. Key goals were to enhance the understanding of techniques and their inter-relationship, to increase awareness of advanced technologies such as software radios and photonics, and to foster a cooperative approach to the development of interference mitigation techniques. The foremost application in mind was the square kilometre array (SKA) and the need to find ways to develop a hierarchical scheme for removing unwanted signals from astronomical data. This paper gives an overview of the topics discussed at the conference and summarises some of the key ideas and results that were presented.

The purpose of this paper is to determine the origin of the photometric variations of 48 Lib using the data from the STEREO and to investigate their relations with the disk structure. The photometric data comprise a period of five years from 2007 to 2011. The spectroscopic data covering the same time interval are provided from the BeSS database. The Hα lines are examined by measuring their equivalent widths and line intensities. Hα variations are then compared with those displayed by the photometric data. From the photometry, high-precision results (10−5 c d−1 in frequency and 10−4 mag in amplitude) are obtained. It is detected that the star has shown 24 frequencies, mainly clustered around the peaks at 2.48896(1) and 5.08150(2) c d−1. The analysis reveals that the photometric frequencies are not due to pulsation, but caused by the rotation, and that the remaining frequencies arise from transient activities on or just above the photosphere. Also, it is shown that the spectroscopic data exhibit a significant Hα variability, and that the Hα line variation depends on the variation of frequency and amplitude, something which has been often proposed in the literature but has never before been demonstrated observationally. This proves that the disk structure and photometric variations are related.

Techniques in QED (quantum electrodynamics) have been developed previously (see for example Melrose and Parle 1983) allowing one to treat electron-photon and photon-photon interactions exactly in the magnetized vacuum and allowing one to include the effects of a medium. These techniques are extended to include particle-particle interactions. Exact cross-sections for electron-electron collisions are derived and compared with known expressions. Such calculations have application in studies of the formation and transfer of radiation in the atmospheres surrounding neutron stars.

The extensive body of broad-band photometric data for SN 1987A obtained at SAAO has been used to derive the bolometric light curve up to day 450 after the outburst. The salient features of the curve are discussed in this paper.

The main objectives of this series of papers are: (1) to demonstrate the existence of serious mutual disagreements between established total (and other integrated) magnitude scales forVirgo galaxies; (2) to attempt to quantify both the systematic and random errors present within these magnitude scales; (3) to investigate the origins of any large error uncovered; and thereby (4) to encourage the general adoption of rigorous total-magnitude measurement procedures by the astronomical community. The ramifications of the findings presented in this series of papers will be discussed in detail at a later date.

In this paper, the first in the series, a self-consistent dataset of trustworthy total-magnitude measurements is compiled for a sample of Virgo galaxies spanning a range of 10 000 in apparent brightness, based on only the most reliable measurements and photometry currently available. This reference dataset, which includes luminosity profile shape information, will be used in subsequent papers as one of the bases for assessing existing magnitude scales forVirgo galaxies. As most published magnitudes are based on B–band observations, this series of papers will also focus primarily on B–bnd measurements.

The five major members of the Sculptor Group of galaxies and NGC 45 have been observed with the Molonglo observatory synthesis telescope. NGC 247 and NGC 300 were not detected and upper limits to their 843 MHz flux densities are given. Radio emission from NGC 7793 is discussed with particular attention to its morphology, radial dependence compared with that of the blue light and possible coincidences between HII regions and 843 MHz peak flux densities.

We present a multifrequency monitoring campaign of PKS 2005–489, a bright and highly variable blazar. Simultaneous observations were completed over a 13 day period in the X-ray with RXTE, in the optical at the CTIO 0.9 m telescope, at TeV energies with CANGAROO-II, and at submillimetre wavelengths with SEST. Previous multiwavelength monitoring campaigns of PKS 2005–489 and other blazars have found complex flux and spectral variability behaviour, with different modes and timescales from days to hours and shorter.

PKS 2005–489 was observed in transition from a quiescent state into the early stages of a flare. A gradual increase in flux density was observed at optical and X-ray wavelengths during 19–27 August 2000, and a dramatic increase in X-ray emission was observed starting on 2 September 2000. Intraday and spectral variability were not detected during the campaign.

Recent observational results are presented which strongly suggest that a much wider range of upper-main-sequence stars have appreciable surface magnetic fields than has previously been believed.

We present an overview of the survey for radio emission from active stars that has been in progress for the last six years using the observatories at Fleurs, Molonglo, Parkes and Tidbinbilla. The role of complementary optical observations at the Anglo-Australian Observatory, Mount Burnett, Mount Stromlo and Siding Spring Observatories and Mount Tamborine are also outlined. We describe the different types of star that have been included in our survey and discuss some of the problems in making the radio observations.

High-resolution spectroscopy of η Mus is combined with literature and new photometry to provide a comprehensive analysis of its components. Our main absolute parameters for the close binary system are M1 and M2 3.34 ± 0.04 M⊙, R1 2.13 ± 0.07 R⊙, R2 2.34 ± 0.10 R⊙; T1 13 000 ± 300, T2 12 600 ± 300, K; and distance 125 ± 10 pc. Our findings update earlier results in a number of respects. We thus confirm that η Mus B is a gravitationally bound companion of the close binary. This relates to the variable γ velocity of the radial velocities of η Mus A. We connect this to the recently discovered member η Mus D, whose orbit we link to new data. We also provide a spectroscopic examination of the Ap star η Mus B, listing over 450 identified lines. We argue that the system is still young, and the apparently anomalous rotation of the close binary’s secondary can be reconciled with its being a physically larger star, still condensing to the zero-age main sequence. Models of young condensing stars permit such expanded states, particularly during the deuterium-burning stage, and our results are in agreement with appropriate low-age models. This possible configuration may make η Mus an important example for testing young star models, formation, and evolution scenarios. This multiple star can be compared with V831 Cen and the general properties related to its membership of the Sco–Cen OB2 association.

We used an Artificial Neural Network (ANN) to derive the orbital parameters of spectroscopic binary stars. Using measured radial velocity data of seven double-lined spectroscopic binary systems V373 Cas, V2388 Oph, V401 Cyg, GM Dra, V523 Cas, AB And and HD 141929, we found corresponding orbital and spectroscopic elements. Our numerical results are in good agreement with those obtained by others using more traditional methods.