Related papers: Adaptive elliptical aperture photometry: a softwar…
As new large-scale astronomical surveys greatly increase the number of objects targeted and discoveries made, the requirement for efficient follow-up observations is crucial. Adaptive optics imaging, which compensates for the image-blurring…
Spectroscopy is a powerful tool for detecting variability in the rapidly oscillating Ap (roAp) stars. The technique requires short integrations times and high resolution, and so is limited to only a few telescopes and instruments. To test…
Proper photometric data are challenging to obtain in the K2 mission of the Kepler space telescope due to strong systematics caused by the two-wheel-mode operation. It is especially true for variable stars wherein physical phenomena occur on…
Intensive reverberation mapping monitoring programs combine ground-based photometric observations from different telescopes, requiring intercalibration of lightcurves to reduce systematic instrumental differences. We present a new iterative…
Light curves for RR Lyrae stars can be difficult to obtain properly in the K2 mission due to the similarities between the timescales of the observed physical phenomena and the instrumental signals appearing in the data. We developed a new…
We define and put at the disposal of the community SOAP, Spot Oscillation And Planet, a software tool that simulates the effect of stellar spots and plages on radial velocimetry and photometry. This paper describes the tool release and…
The rapidly oscillating Ap stars are of importance for studying the atmospheric structure of stars where the process of chemical element diffusion is significant. We have performed a survey for rapid oscillations in a sample of 9 luminous…
The rapidly oscillating Ap (roAp) stars exhibit pulsational photometric and/or radial velocity variations on time scales of several minutes, which are essential to test current pulsation models as well as our assumptions of atmospheric…
We have carried out a survey of short-period pulsations among a sample of carefully chosen cool Ap stars using time-resolved observations with the UVES spectrometer at the ESO 8-m VLT telescope. Here we report the discovery of pulsations…
Substellar companions such as exoplanets and brown dwarfs exhibit changes in brightness arising from top-of-atmosphere inhomogeneities, providing insights into their atmospheric structure and dynamics. This variability can be measured in…
More than 450 exoplanets are known and this number increases nearly every day. Only a few constraints on their orbital parameters and physical characteristics can be determined, as most exoplanets are detected indirectly. Measuring the…
We develop a software package SPADExp (simulator of photoemission angular distribution for experiments) to calculate the photoemission angular distribution (PAD), which is the momentum dependence of spectrum intensity in angle-resolved…
We present the analysis of time-series of photoelectric data of a Bp star and four new Ap stars observed photoelectrically under the Nainital-Cape survey programme. The project was started about two decades ago, aiming to search for new…
We present the method of the Extended Aperture Photometry (EAP) that we applied to K2 RR Lyrae stars. Our aim is to minimize the instrumental variations of attitude control maneuvers by using apertures that cover the positional changes in…
Large ground-based telescopes equipped with adaptive optics (AO) systems have ushered in a new era of high-resolution infrared photometry and astrometry. Relative astrometric accuracies of <0.2 mas have already been demonstrated from…
Adaptive optics is a technique mostly used on large telescopes. It turns out to be challenging for smaller telescopes (0.5~2m) due to the small isoplanatic angle, small subapertures and high correction speeds needed at visible wavelengths,…
The 60 known rapidly oscillating Ap (roAp) stars are excellent laboratories to test pulsation models in the presence of stellar magnetic fields. Our survey is dedicated to search for new group members in the Northern Hemisphere. We attempt…
Direct imaging and spectral characterization of exoplanets using extreme adaptive optics (ExAO) is a key science goal of future extremely large telescopes and space observatories. However, quasi-static wavefront errors will limit the…
Near-diffraction limited imaging and spectroscopy in the visible on large (8-10 meter) class telescopes has proved to be beyond the capabilities of current adaptive optics technologies, even when using laser guide stars. The need for high…
One of the main goals of the COROT mission is to get precise photometric observations of selected bright stars in order to allow the modelling of their interior through asteroseismology. However, in order to interpret the…