Related papers: Optimizing Weights for the Detection of Stellar Os…
We present a multi-calibrator solution, i.e. MultiView, to achieve accurate astrometry on the level of the thermal noise at low VLBI frequencies dominated by ionospheric residuals. We demonstrate on L-band VLBA observations how MultiView…
The rich absorption spectra of Sun-like stars are enticing probes for variations in the fine-structure constant, $\alpha$, which gauges the strength of electromagnetism. While individual line wavelengths are sensitive to $\alpha$, they are…
We present models of alpha Centauri A and B implementing an entropy calibration of the mixing-length parameter alpha_MLT, recently developed and successfully applied to the Sun (Spada et al. 2018, ApJ, 869, 135). In this technique the value…
The classical spectrum analysis methods utilize window functions to reduce the masking effect of a strong spectral component over weaker components. The main cost of side-lobe reduction is the reduction of signal-to-noise ratio (SNR) level…
Stellar inclination is an important parameter for many astrophysical studies. Although different techniques allow us to estimate stellar inclinationt for fast rotators, it becomes much more difficult when stars are rotating slower than…
We lay out and apply methods to use proper motions of individual kinematic tracers for estimating the dynamical mass of star clusters. We first describe a simple projected mass estimator and then develop an approach that evaluates directly…
We introduce a methodology to test models with spatial variations of the fine-structure constant $\alpha$, based on the calculation of the angular power spectrum of these measurements. This methodology enables comparisons of observations…
Astrometry has long been a promising technique for exoplanet detection. At the theoretical limits, astrometry would allow for the detection of smaller planets than previously seen by current exoplanet search methods, but stellar activity…
Modern data are increasingly both high-dimensional and heteroscedastic. This paper considers the challenge of estimating underlying principal components from high-dimensional data with noise that is heteroscedastic across samples, i.e.,…
Alpha Centauri A is the closest solar-type star to the Sun and offers an excellent opportunity to detect the thermal emission of a mature planet heated by its host star. The MIRI coronagraph on JWST can search the 1-3 AU (1"-2") region…
The physiology of the dark adaption process of the eye is revisited from an astronomical point of view. A new method for the magnitude estimation of a star is presented. It is based upon the timing of the physiological cycle of the…
We have developed a new technique for weak lensing analysis, with which the effect of the point spread function (PSF) on small galaxy images can be corrected for accurately. Rather than relying on weighted second moments of detected images,…
Telescopes measuring cosmic microwave background (CMB) polarization on large angular scales require exquisite control of systematic errors to ensure the fidelity of the cosmological results. In particular, far-sidelobe contamination from…
Since the volume accessible to galaxy surveys is fundamentally limited, it is extremely important to analyse available data in the most optimal fashion. One way of enhancing the cosmological information extracted from the clustering of…
Binary asteroids probe thermal-radiation effects on the main-belt asteroids' evolution. We discuss the possibility of detecting binary minor planet systems by the astrometric wobble of the center-of-light around the center-of-mass. This…
The precise mechanisms that provide the non-radiative energy for heating the chromosphere and the corona of the Sun and those of other stars constitute an active field of research. By studying stellar chromospheres one aims at identifying…
Stellar activity is the main limitation to the detection of Earth-twins using the RV technique. Despite many efforts in trying to mitigate the effect of stellar activity using empirical and statistical techniques, it seems that we are…
We implement an algorithm based on the weighted stacking of astronomical images that can combine different observations of the same region of the sky removing the interfering signals. We develop a C++ code that takes as input a set of…
Hot subdwarf stars are particularly challenging for asteroseismology due to their rapid pulsation periods, intrinsic faintness and relative rarity both in the field and in clusters. These features have ensured that the preferred method of…
Stellar activity interferes with precise radial velocity measurements and limits our ability to detect and characterize planets, particularly Earth-like planets. We introduce \aestra (Auto-Encoding STellar Radial-velocity and Activity), a…