相关论文: Photometric stellar variation due to extra-solar c…
We investigate whether rings around extrasolar planets could be detected from those planets' transit lightcurves. To this end we develop a basic theoretical framework for calculating and interpreting the lightcurves of ringed planet…
Stellar occultations have been used to search for Kuiper Belt and Oort Cloud objects. We propose a search for interstellar objects based on the characteristic durations ($\sim 0.1 \mathrm{s}$) of their stellar occultation signals and high…
A recent analysis of high precision photometry obtained using the Kepler spacecraft has revealed two surprising discoveries: (1) over 860 main sequence A-type stars -- approximately 40% of those identified in the Kepler field -- exhibit…
About 10% of upper main sequence stars are characterised by the presence of chemical peculiarities, often found together with a structured magnetic field. The atmospheres of most of those chemically peculiar stars present surface spots,…
Planetary companions to the source stars of a caustic-crossing binary microlensing events can be detected via the deviation from the parent light curves created when the caustic magnifies the star light reflecting off the atmosphere or…
The Sun and stars with low magnetic activity levels, become photometrically brighter when their activity increases. Magnetically more active stars display the opposite behaviour and get fainter when their activity increases. We reproduce…
In terms of scientific output, the best way to study solar system bodies is sending spacecraft to make in-situ measurements or to observe at close distance. Probably, the second best means to learn about important physical properties of…
We discuss the interpretation of distortions to stellar spectral lines with particular attention to line bisectors in the presence of an orbiting planetary companion. We present a simple model whereby light reflected by the companion can…
Mountain ranges, volcanoes, trenches, and craters are common on rocky bodies throughout the Solar System, and we might we expect the same for rocky exoplanets. With ever larger telescopes under design and a growing need to not just detect…
If a source star is gravitationally microlensed by a multiple lens system, the resulting light curve can have significant deviations from the standard form of a single lens event. The chance to produce significant deviations becomes…
We consider small-scale spheroidal clusters of weakly interacting massive particles in our Galaxy as non-compact gravitational microlenses and predict the appearance of caustics in the plane of a lensed source. The crossing of these…
Solar and stellar externally occulted coronagraphs share similar concepts, but are actually very different because of geometric characteristics. Solar occulters were first developed with a simple geometric model of diffraction perpendicular…
We predict how a remote observer would see the brightness variations of giant planets similar to Jupiter and Saturn as they orbit their central stars. We model the geometry of Jupiter, Saturn and Saturn's rings for varying orbital and…
The Oort cloud is presumably a pristine relic of the Solar System formation. Detection of the Oort cloud may provide information regarding the stellar environment in which the Sun was born and on the planetesimal population during the outer…
The (magnetic) chemically peculiar (CP) stars of the upper main sequence are well-suited laboratories for investigating the influence of magnetic fields on the stellar surface because they produce abundance inhomogeneities (spots), which…
Magnetic, chemically peculiar stars are known for exhibiting surface abundance inhomogeneities (chemical spots) that lead to photometric and spectroscopic variability with the rotation period. It is commonly assumed that the surface…
The detectability of moons of extra-solar planets is investigated, focussing on the time-of-arrival perturbation technique, a method for detecting moons of pulsar planets, and the photometric transit timing technique, a method for detecting…
Stellar surface processes represent a fundamental limit to the detection of extrasolar planets with the currently most heavily-used techniques. As such, considerable effort has gone into trying to mitigate the impact of these processes on…
We consider microlensing of an elliptical source crossing a fold caustic. We derive a simple expression for the light curve of a source with uniform surface brightness that is accurate to third order in the ellipticity e (yielding errors of…
We present theoretical predictions for photometric and spectroscopic signatures of rings around transiting extrasolar planets. On the basis of a general formulation for the transiting signature in the stellar light curve and the velocity…