We present low resolution maps, of a 4' × 0'.5 region, of comet Halley, in photometric bands J and K, a central scan in the H band and JHKL photometry taken with the 1.5 m Sanchez-Magro Telescope of the Instituto de Astrofisica de Canarias. We obtain central and integrated magnitudes and colours and discuss its variation with distance from the

Presented are the results of a large and deep optical-near-infrared multi-epoch survey of the Praesepe open star cluster using data from the UKIRT Infrared Deep Sky Survey (UKIDSS) Galactic Clusters Survey. Multiple colour-magnitude diagrams were used to select potential members and proper motions were used to assign levels of membership

The double distance and metallicity frontier marked by the SMC has been finally broken with the aid of powerful multi-object spectrographs installed at 8-10m class telescopes. VLT, GTC and Keck have enabled studies of massive stars in dwarf irregular galaxies of the Local Group with poorer metal-content than the SMC. The community is working to

The authors present maps of a 3arcmin×2arcmin region of the inner coma of comet P/Halley, at 10arcsec resolution, in CN (3883 Å); C2 (5100 Å); C3 (4040 Å); CN (4216 Å); NH2 (6107 Å); [O I] (6300 Å) and CH (4322 Å). The maps were prepared from multi-position absolute spectrophotometry of comet Halley, with 3.6 Å resolution, in the wavelength range

Aims: We study in detail nine sources in the direction of the young σ Orionis cluster, which is considered to be a unique site for studying stellar and substellar formation. The nine sources were selected because of their peculiar properties, such as extremely-red infrared colours or excessively strong Hα emission for their blue optical colours

In this study we present the absolute magnitude calibrations of thin-disc main-sequence stars in the optical , and in the near-infrared . Thin-disc stars are identified by means of Padova isochrones, and absolute magnitudes for the sample are evaluated via the newly reduced Hipparcos data. The obtained calibrations cover a large range of spectral