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

Spectrophotometric observations in the optical and near-infrared of six giant H II regions in the high metallicity spiral galaxy M51 are presented. Five of the regions are located in the spiral arms, and the sixth one is very close to the nucleus. These observations and the application of adequate photo-ionization models allow the determination of

Spectrophotometric data of giant H II regions covering the spectral range from λ3600 to 9700 Å in the spiral galaxies M101 and M51 have been analyzed in order to determine reliable chemical abundances and radial gradients. The behaviour of the S/O ratio with metallicity is also explored. The data are consistent, within the errors, with a constant S