The quality of profile fitting of resolved stars depends ultimately upon the accuracy with which spectral differences of the sources are retrievable within the data, because the radiation color of well-separated known sources can serve as an indicator of the origin of the optical depth variations one observes during the night. The particularities of the whole sky imager (WSI) detector and optic...

We present a thorough investigation of stellar photometry based on HST imaging of crowded fields at 85 and 10 from the centre of the high-surface brightness elliptical galaxy M32. The Principal Investigators of the present archive data have elsewhere presented an impressive colour-magnitude diagram of the field at 85. Based on the same data we enlarge on their photometric analysis and supplemen...

Online Digital Sky Survey (DSS) material is often used to obtain information on newly discovered variable stars for older epochs (e.g. Nova progenitors, flare stars, . . . ). We present here the results of an investigation of photometry on online digital sky survey material in small fields calibrated by CCD sequences. We compared different source extraction mechanisms and found, that even down ...

The different algorithms appropriate for point source photometry on data from the SPIRE instrument on-board the Herschel Space Observatory, within the Herschel Interactive Processing Environment (HIPE) are compared. Point source photometry of a large ensemble of standard calibration stars and dark sky observations is carried out using the 4 major methods within HIPE: SUSSEXtractor, DAOphot, the...

The UKIRT Infrared Deep Sky Survey (UKIDSS) is the first of a new generation of hemispheric imaging projects to extend the work of the Two Micron All Sky Survey (2MASS) by reaching three magnitudes deeper in Y JHK imaging, to K = 18.2 (5σ, Vega) over wide fields. Better complementing existing optical surveys such as the Sloan Digital Sky Survey (SDSS), the resulting public imaging catalogues pr...

We report the first results of our programme to obtain multi-epoch radial velocity measurements of stars with a strong far-UV excess to identify post common-envelope binaries (PCEBs). The targets have been identified using optical photometry from SDSS DR4, ultraviolet photometry from GALEX GR2 and proper motion information from SDSS DR5. We have obtained spectra at two or more epochs for 36 tar...

We present new BVIC photometry for 350 Pleiades proper motion members with 9 < V ! 17. Importantly, our new catalog includes a large number of Kand early M-type stars, roughly doubling the number of low-mass stars with well-calibrated Johnson/Cousins photometry in this benchmark cluster. We combine our new photometry with existing photometry from the literature to define a purely empirical isoc...

The rapid variability of blazars in almost all wavelengths is now well established. Two days of observations were conducted at the Palomar Observatory during the nights of 25 and 26 February 1997 with the 5-meter Hale telescope, in order to search for rapid variability in the near-infrared (NIR) bands J, H, Ks for a selection of eight blazars. With the possible exception of 1156+295 (4C 29.45),...