We present the first analysis of spectroscopic and photometric observations of the two southern eclipsing binary stars, V349 Ara and V4403 Sgr. Radial velocity curves of these two systems obtained at the South African Astronomical Observatory and their V light curves from the All Sky Automated Survey were solved simultaneously using the Wilson–Devinney code. Our photometric models describe these two systems as Algol-like binary stars with detached configurations. The masses and radii were found to be 2.59 ± 0.07 M⊙, 3.60 ± 0.07 R⊙ and 2.51 ± 0.06 M⊙, 4.15 ± 0.07 R⊙ for the primary and secondary components of V349 Ara, respectively. Those of V4403 Sgr were derived to be 1.33 ± 0.02 M⊙, 1.74 ± 0.02 R⊙ and 1.59 ± 0.03 M⊙, 2.50 ± 0.03 R⊙ for the primary and secondary components, respectively. The distances to V349 Ara and V4403 Sgr were computed to be 677 ± 36 and 199 ± 10 pc from the dynamic parallax, respectively, taking into account interstellar extinction. The evolution cases of these two systems are also examined. Both components of these two systems are evolved main-sequence stars, and the dynamic ages were estimated as approximately 0.67 and 2.29 Gyr for V349 Ara and V4403 Sgr, respectively, when compared to Geneva theoretical evolution models.

The Lyman alpha emission line (Lyα) of neutral hydrogen (Hi) is intrinsically the brightest emission feature in the spectrum of astrophysical nebulae, making it a very attractive observational feature with which to survey galaxies. Moreover as an ultraviolet resonance line, Lyα possesses several unique characteristics that make it useful to study the properties of the interstellar medium and ionising stellar population at all cosmic epochs. In this review, I present a summary of Lyα observations of galaxies in the nearby universe. By ultraviolet continuum selection, at the magnitudes reachable with current facilities, only ≈ 5% of the local galaxy population shows a Lyα equivalent width (WLyα) that exceeds 20 Å. This fraction increases dramatically at higher redshifts, but only in the local universe can we study galaxies in detail and assemble unprecedented multi-wavelength datasets. I discuss many local Lyα observations, showing that when galaxies show net Lyα emission, they ubiquitously also produce large-scale halos of scattered Lyα, that dominate the integrated luminosity. Concerning global measurements, we discuss how WLyα and the Lyα escape fraction (fLyαesc) are higher (WLyα ≳ 20 Å and fLyαesc ≳ 10%) in galaxies that represent the less massive and younger end of the distribution for local objects. This is connected with various properties, such that Lyα-emitting galaxies have lower metal abundances (median value of 12 + log(O/H) ~ 8.1) and dust reddening. However, the presence of galactic outflows/winds is also vital to Doppler shift the Lyα line out of resonance with the atomic gas, and high WLyα is found only among galaxies with winds faster than ~ 50 km s−1. The empirical evidence is then assembled into a coherent picture, and the requirement for star-formation-driven feedback is discussed in the context of an evolutionary sequence where the interstellar medium is accelerated and/or subject to hydrodynamical instabilities, which reduce the scattering of Lyα. Concluding remarks take the form of perspectives upon future developments, and the most pressing questions that can be answered by observation.

In the original publication of “Image Simulation for Mingantu Ultrawide Spectral Radioheliograph in the Decimetre Wave Range,” by Jing Du, Yihua Yan, Wei Wang, and Donghao Liu, there were concerns regarding ambiguity of a few statements. To clarify, the authors have submitted an update regarding Table 6 (p. 12) and the supporting language (p. 13):

GLEAM, the GaLactic and Extragalactic All-sky MWA survey, is a survey of the entire radio sky south of declination + 25° at frequencies between 72 and 231 MHz, made with the MWA using a drift scan method that makes efficient use of the MWA’s very large field-of-view. We present the observation details, imaging strategies, and theoretical sensitivity for GLEAM. The survey ran for two years, the first year using 40-kHz frequency resolution and 0.5-s time resolution; the second year using 10-kHz frequency resolution and 2 s time resolution. The resulting image resolution and sensitivity depends on observing frequency, sky pointing, and image weighting scheme. At 154 MHz, the image resolution is approximately 2.5 × 2.2/cos (δ + 26.7°) arcmin with sensitivity to structures up to ~ 10° in angular size. We provide tables to calculate the expected thermal noise for GLEAM mosaics depending on pointing and frequency and discuss limitations to achieving theoretical noise in Stokes I images. We discuss challenges, and their solutions, that arise for GLEAM including ionospheric effects on source positions and linearly polarised emission, and the instrumental polarisation effects inherent to the MWA’s primary beam.

We present a complete spatial and dynamical study of the poorly populated stellar system ESO65SC03. The radial distribution of the system gives a core and cluster radii of 1.10±0.63 and 5.36±0.24 arcmin, respectively. The SNDP does not show any clear enhancement of the surface stellar number density between the stars of the system and the field regions. We derive the optimum isochrone solution for a particular grid size in the CMD using the statistical cleaning procedure. Using the statistically cleaned CMDs, we find the distance modulus, (m − M)0, and reddening, E(B − V), of the system to be 11.8±0.2 and 0.45 mag, respectively. The mean proper motion of this system is − 5.37±0.81 mas yr−1 and 0.31±0.40 in RA and DEC directions, respectively. The mean proper motion of this system is found to be almost similar to the field region. The mass function for the brighter stars is found to be too high for the system to be an open cluster. These combined results place constraints on whether stellar system ESO65SC03 is a POCR or an Asterism. Our understanding is that the ESO65SC03 is in a stage of POCR by losing their main-sequence stars in the dynamic evolution processes.

We carried out light curve solutions of ten detached eclipsing eccentric binaries observed by Kepler. The formal errors of the derived parameters from the light curve solutions are below 1%. Our results give indications that the components of the eccentric binaries (especially those with mass ratios below 0.5) do not follow precisely the empirical relations between the stellar parameters derived from the study of circular-orbit binaries. We found the following peculiarities of the targets: (a) the components of KIC 9474969 have almost the same temperatures while their radii and masses differ by a factor around 2.5; (b) KIC 6949550 reveals semi-regular light variations with an amplitude of 0.004 and a period around 7 d which are modulated by long-term variations; (c) KIC 6220470, KIC 11071207, and KIC 9474969 exhibit tidally induced ‘hump’ around the periastron. These are the targets with the biggest relative radii of our sample. We derived the dependence of the hump amplitude on the relative stellar radii, eccentricity, and mass ratio of eccentric binary consisting of MS stars.

The MUSER is a solar-dedicated radio interferometric array, which will observe the Sun over a wide range of radio frequencies (0.4–15 GHz), and make high time, space and frequency resolution images of the Sun simultaneously. MUSER is located in Mingantu Station in Inner Mongolia of China, which is about 400 kilometres away from Beijing. MUSER consists of two arrays: MUSER-I and MUSER-II. MUSER-I contains 40 antennas with 4.5-m aperture operating at 400 MHz to 2 GHz. MUSER-II contains 60 antennas with 2-m aperture operating at 2 to 15 GHz. Currently, MUSER has already been established and entered into the stage of test observation. This work is focus on the imaging performance of MUSER-I. This paper introduces MUSER-I briefly, presents the analysis of the array configurations, and evaluates the image quality mainly using the dynamic range, fidelity index, and the peak signal-to-noise ratio, also make some actual solar model simulations with CASA, the results will be shown below.

Results from long-term multicolour optical photometric observations of the pre-main-sequence stars FHO 26, FHO 27, FHO 28, FHO 29, and V1929 Cyg collected during the period from 1997 June to 2014 December are presented. The objects are located in the dense molecular cloud L935, named ‘Gulf of Mexico’, in the field between the North America and Pelican nebulae. All stars from our study exhibit strong photometric variability in all optical passbands. Using our BVRI observations and data published by other authors, we tried to define the reasons for the observed brightness variations. The presented paper is a part of our long-term photometric study of the young stellar objects in the region of ‘Gulf of Mexico’.

We present observations of the first 10° of longitude in the Mopra CO survey of the southern Galactic plane, covering Galactic longitude l = 320–330° and latitude b = ±0.5°, and l = 327–330°, b = +0.5–1.0°. These data have been taken at 35-arcsec spatial resolution and 0.1 km s−1 spectral resolution, providing an unprecedented view of the molecular clouds and gas of the southern Galactic plane in the 109–115 GHz J = 1–0 transitions of 12CO, 13CO, C18O, and C17O. Together with information about the noise statistics from the Mopra telescope, these data can be retrieved from the Mopra CO website and the CSIRO-ATNF data archive.

Mapping the diversity of SNe to progenitor properties is key to our understanding of stellar evolution and explosive stellar death. Investigations of the immediate environments of SNe allow statistical constraints to be made on progenitor properties such as mass and metallicity. Here, we review the progress that has been made in this field. Pixel statistics using tracers of e.g. star formation within galaxies show intriguing differences in the explosion sites of, in particular SNe types II and Ibc (SNe II and SNe Ibc respectively), suggesting statistical differences in population ages. Of particular interest is that SNe Ic are significantly more associated with host galaxy Hα emission than SNe Ib, implying shorter lifetimes for the former. In addition, such studies have shown (unexpectedly) that the interacting SNe IIn do not explode in regions containing the most massive stars, which suggests that at least a significant fraction of their progenitors arise from the lower end of the core-collapse SN mass range. Host H ii region spectroscopy has been obtained for a significant number of core-collapse events, however definitive conclusions on differences between distinct SN types have to-date been elusive. Single stellar evolution models predict that the relative fraction of SNe Ibc to SNe II should increase with increasing metallicity, due to the dependence of mass-loss rates on progenitor metallicity. We present a meta-analysis of all current host H ii region oxygen abundances for CC SNe. It is concluded that the SN II to SN Ibc ratio shows little variation with oxygen abundance, with only a suggestion that the ratio increases in the lowest bin. Radial distributions of different SNe are discussed, where a central excess of SNe Ibc has been observed within disturbed galaxy systems, which is difficult to ascribe to metallicity or selection effects. Environment studies are also being undertaken for SNe Ia, where constraints can be made on the shortest delay times of progenitor systems. It is shown that ‘redder’ SNe Ia are more often found within star-forming regions. Environment studies are evolving to enable studies at higher spatial resolutions than previously possible, while in addition the advent of wide-field integral field unit instruments allows galaxy-wide spectral analyses which will provide fruitful results to this field. Some example contemporary results are shown in that direction.

We propose that observations of ‘hidden’ magnetars in central compact objects can be used to probe crustal activity of neutron stars with large internal magnetic fields. Estimates based on calculations by Perna & Pons, Pons & Rea and Kaminker et al. suggest that central compact objects, which are proposed to be ‘hidden’ magnetars, must demonstrate flux variations on the time scale of months–years. However, the most prominent candidate for the ‘hidden’ magnetars — CXO J1852.6+0040 in Kes 79 — shows constant (within error bars) flux. This can be interpreted by lower variable crustal activity than in typical magnetars. Alternatively, CXO J1852.6+0040 can be in a high state of variable activity during the whole period of observations. Then we consider the source 1E161348 − 5055 in RCW103 as another candidate. Employing a simple 2D-modelling we argue that properties of the source can be explained by the crustal activity of the magnetar type. Thus, this object may be supplemented for the three known candidates for the ‘hidden’ magnetars among central compact objects discussed in literature.

The conversion of a former 100-foot (30-m) telecommunications antenna (Earth Station) in New Zealand into a radio telescope is described. A specification of the antenna and the priorities for its actual conversion are initially presented. In describing the actual conversion, particular emphasis is given to mechanical and electrical components, as well as to the design of the telescope control system, telescope networking for VLBI operations, and telescope maintenance. Plans for RF, front- and back-end developments based upon radio astronomical priorities are outlined.