相关论文: Benchmark tests of transmission spectroscopy using…
What makes the study of exoplanetary atmospheres so hard is the extraction of its tiny signal from observations, usually dominated by telluric absorption, stellar spectrum and instrumental noise. The High Resolution Spectroscopy has emerged…
Super Soft X-ray Sources (SSS) are powered by nuclear burning on the surface of an accreting white dwarf, they are seen around 0.1-1 keV (thus in the soft X-ray regime), depending on effective temperature and the amount of intervening…
Near-infrared photometry of transiting extrasolar planets can be of great scientific value. It is however not straightforward to reach the necessary millimagnitude precision. Here we report on our attempts to observe transits and secondary…
The Wide Field Camera Transit Survey is a pioneer program aimed to search for extra-solar planets in the near-infrared. The standard data reduction pipeline of the program uses aperture photometry to construct the light curves. We…
Brown dwarfs are compact objects that do not reach temperatures high enough to produce sustained hydrogen fusion. Consequently, they cool over time, gradually evolving through later spectral types. In fact, three new spectral types (L, T,…
We present theoretical wavelength-dependent transit light curves for the giant planet HD209458b based on a number of state of the art 3D radiative hydrodynamical models. By varying the kinematic viscosity in the model we calculate…
Modern theoretical estimates show that with the help of real equipment we are able to detect large satellites of exoplanets (about the size of the Ganymede), although, numerical attempts of direct exomoon detection were unsuccessful. Lots…
The characteristics of an x-ray spectrum can greatly influence imaging and related tasks. In practice, due to the pile-up effect of the detector, it's difficult to directly measure the spectrum of a CT scanner using an energy resolved…
We present broad-band photometry of eleven planetary transits of the hot Jupiter WASP-74b, using three medium-class telescopes and employing the telescope-defocussing technique. Most of the transits were monitored through I filters and one…
White dwarfs represent the end stage for 97% of stars, making precise parameter measurement crucial for understanding stellar evolution. Traditional estimation methods involve fitting spectra or photometry, which require high-quality data.…
Many brown dwarfs are on ultra-short period and tidally-locked orbits around white dwarf hosts. Because of these small orbital separations, the brown dwarfs are irradiated at levels similar to hot Jupiters. Yet, they are easier to observe…
Nearby M dwarf systems currently offer the most favorable opportunities for spectroscopic investigations of terrestrial exoplanet atmospheres. The LTT~1445 system is a hierarchical triple of M dwarfs with two known planets orbiting the…
White dwarf photospheric parameters are usually obtained by means of spectroscopic or photometric analysis. These results are not always consistent with each other, with the published values often including just the statistical…
Context: Transmission spectroscopy has proven to be a useful tool for the study of exoplanet atmospheres, and has lead to the detection of a small number of elements and molecules (Na, K, H$_2$O), but also revealed that many planets show…
The probability that an existing planetary transit is detectable in one's data is sensitively dependent upon the window function of the observations. We quantitatively characterize and provide visualizations of the dependence of this…
The forthcoming space missions, able to detect Earth-like planets by the transit method, will a fortiori also be able to detect the transit of artificial planet-size objects. Multiple artificial objects would produce lightcurves easily…
We obtained long-slit optical spectroscopy of one transit of WASP-48b with the Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy (OSIRIS) spectrograph at the 10.4 m Gran Telescopio Canarias (GTC). We…
The noise of a device under test (DUT) is measured simultaneously with two instruments, each of which contributes its own background. The average cross power spectral density converges to the DUT power spectral density. This method enables…
The low-resolution transmission spectra of ultra-hot Jupiters observed shortward of 0.5 microns indicate strong absorption at short-wavelengths. Previous explanations have included scattering, photochemistry, escaping metals, and…
We present broad-band photometry of five transits in the planetary system WASP-36, totaling 17 high-precision light curves. Four of the transits were simultaneously observed in four passbands (g, r, i, z), using the telescope-defocussing…