We report the discovery of a very cool brown dwarf, ULAS J003402.77-005206.7 (ULAS J0034-00), identified in the UKIRT Infrared Deep Sky Survey First Data Release. We provide optical, near-infrared, and mid-infrared photometry of the source, and two near-infrared spectra. Comparing the spectral energy distribution of ULAS J0034-00 to that of the T8

We present results from a multisite (`Whole Earth Telescope') photometric campaign on PG 1336-018, the close eclipsing binary system containing a pulsating subdwarf B (sdB) star. The main part of the campaign (1999 April) resulted in ~172 h of observations, representing a coverage of about 47 per cent, and additional data were obtained outside the

We report on the results of optical, near-infrared (NIR), and mid-infrared observations of the black hole X-ray binary candidate (BHB) MAXI J1535–571 during its 2017/2018 outburst. During the first part of the outburst (MJD 58004–58012), the source shows an optical–NIR spectrum that is consistent with an optically thin synchrotron power law from a

We present new optical and ultraviolet spectroscopy of the anomalous EUV emitter HD 199143 (F8V). High resolution spectra in the Halpha and Na I D wavelength regions show evidence for very rapid (a few hundred km/s) rotation of the stellar photosphere. Using archive IRAS data we also show that the star has excess emission above photospheric levels

The CoRoT and Kepler space missions have commenced a golden era in the field of asteroseismology. The precise and long-term uninterrupted photometric time series from space, now available for thousands of stars, enable the detection of low-amplitude frequencies, revealing new and surprising pulsational results. From the following overview of the

We present the first detailed spatiokinematical analysis and modelling of the planetary nebula Abell 41, which is known to contain the well-studied close-binary system MT Ser. This object represents an important test case in the study of the evolution of planetary nebulae with binary central stars as current evolutionary theories predict that the