Wide-field survey instruments are used to efficiently observe large regions of the sky. To achieve the necessary field of view, and to provide a higher signal-to-noise ratio for faint sources, many modern instruments are undersampled. However, precision photometry with undersampled imagers requires a detailed understanding of the sensitivity variations on a scale much smaller than a pixel. To a...

This paper reviews the state of the art in follow-up photometry for planetary transit searches. Three topics are discussed: (1) Photometric monitoring of planets discovered by radial velocity to detect possible transits (2) Follow-up photometry of candidates from photometric transit searches to weed out eclipsing binaries and false positives (3) High-precision lightcurves of known transiting pl...

A high accuracy photometric reduction method is needed to take full advantage of the potential of the transit method for the detection and characterization of exoplanets, especially in deep crowded fields. In this context, we present DECPHOT, a new deconvolution-based photometry algorithm able to deal with a very high level of crowding and large variations of seeing. It also increases the resol...

This is the first of a series of papers devoted to a global study of the photometric properties of the red stellar sequences in a complete sample of the Large Magellanic Cloud clusters, by means of near infrared array photometry. Deep J,H,Ks photometry and accurate Color Magnitude Diagrams down to K ≈ 18.5, Based on observations collected at the European Southern Observatory, La Silla, Chile, u...

BV RI CCD-based and near-IR (J) imaging, together with unfiltered photometry of the hot subdwarf B star PG 0856+121 are reported. Two close, faint, red, point-like sources are resolved. They account for the previously reported IR excess observed in this hot subdwarf. In addition, the new unfiltered differential photometry of PG 0856+121 confirms its previously reported pulsational nature. A com...

To describe human perception related phenomena, one can distinguish among three classes of quantities: psychological ones reflecting perception, quantities directly related to the physical stimuli and psychophysical quantities that can be measured using physical quantities, but which reflect some characteristics of the human sensory system. Related to vision the three classes are the terms rela...

It is shown that in very crowded elds, such as the cores of globular clusters, aperture pho-tometry of subsampled-deconvolved HST/WFPC2 images gives statistically better results than any of the following DAOPHOT-II reductions of the original data: aperture photometry, proole-tting photometry, and the hybrid method of aperture photometry on neighbour-subtracted images. Furthermore , the deconvol...

Aims. Using the CoRoT space based photometry of the O-type binary HD 46149, stellar atmospheric effects related to rotation can be separated from pulsations, because they leave distinct signatures in the light curve. This offers the possibility of characterising and exploiting any pulsations seismologically. Methods. Combining high-quality space based photometry, multi-wavelength photometry, sp...

We report J , H , and K photometry of 86 stars in 40 fields in the northern hemisphere. The fields are smaller than or comparable to a 4×4 arcmin field-ofview, and are roughly uniformly distributed over the sky, making them suitable for a homogeneous broadband calibration network for near-infrared panoramic detectors. K magnitudes range from 8.5 to 14, and J − K colors from -0.1 to 1.2. The pho...

We present results of large-aperture (D1@) JK photometry and CCD BV RI photometry near the centers of three distant (0.111 z1 0.22), rich Abell clusters of galaxies. The colors of the integrated light are consistent with those of nearby E and S0 galaxies. The absence of anomalous reddening implies that no more than 2 h~1% (1 p limit) of the dark matter in these clusters can be in the form of lo...