Related papers: Limits to dynamic range in GHz-THz single-dish pla…
The discovery and characterization of exoplanets around nearby stars is driven by profound scientific questions about the uniqueness of Earth and our Solar System, and the conditions under which life could exist elsewhere in our Galaxy.…
We show that the maximal frequency of cosmic gravitons must not exceed the THz domain. From a classical viewpoint, both in conventional inflationary scenarios and in bouncing models the largest frequency of the spectrum overshoots the MHz…
We present two algorithms to identify and flag radio frequency interference (RFI) in radio interferometric imaging data. The first algorithm utilizes the redundancy of visibilities inside a UV cell in the visibility plane to identify…
The radial velocity (RV) detection of exoplanets is challenged by stellar spectroscopic variability that can mimic the presence of planets and by instrumental instability that can further obscure the detection. Both stellar and instrumental…
Time-varying inhomogeneities on stellar surfaces constitute one of the largest sources of radial velocity (RV) error for planet detection and characterization. We show that stellar variations, because they manifest on coherent, rotating…
Both the quality and amount of astrophysical data are steadily increasing over time owing to the improvement of telescopes and their instruments. This requires corresponding evolution of the techniques used for obtaining and analyzing the…
Solar contamination, due to moonlight and atmospheric scattering of sunlight, can cause systematic errors in stellar radial velocity (RV) measurements that significantly detract from the ~10cm/s sensitivity required for the detection and…
A systematic programme of calibration observations was carried out to monitor the performance of the SPIRE FTS instrument on board the Herschel Space Observatory. Observations of planets (including the prime point-source calibrator,…
Ongoing ground-based radial-velocity observations seeking to detect circumbinary planets focus on single-lined binaries even though over nine in every ten binary systems in the solar-neighbourhood are double-lined. Double-lined binaries are…
Searches for small exoplanets around solar-type stars are limited by stellar physical variability. While chromospheric variability is well studied, observing, modeling. and understanding the much smaller fluctuations in photospheric…
Context: Extended circumstellar emission has been detected within a few 100 milli-arcsec around > 10% of nearby main sequence stars using near-infrared interferometry. Follow-up observations using other techniques, should they yield similar…
Context: The technique of matching synthetic spectra computed with theoretical stellar atmosphere models to the observations is widely used in deriving fundamental parameters of massive stars. When applied to binaries, however, these models…
In the last two decades, thousands of extrasolar planets were discovered based on different observational techniques, and their number must increase substantially in virtue of the ongoing and near-future approved missions and facilities. It…
Testing 3D hydrodynamic models of stellar atmospheres is feasible by retrieving spectral line shapes across stellar disks, using differential spectroscopy during exoplanet transits. From synthetic data at hyper-high spectral resolution,…
Finding low-mass planets around solar-type stars requires to understand the physical variability of the host star, which greatly exceeds the planet-induced radial-velocity modulation. This project aims at analyzing - observationally and…
We provide an overview of stellar variability in the first quarter of data from the Kepler mission. The intent of this paper is to examine the entire sample of over 150,000 target stars for periodic behavior in their lightcurves, and relate…
The spectrum of an exoplanet reveals the physical, chemical, and biological processes that have shaped its history and govern its future. However, observations of exoplanet spectra are complicated by the overwhelming glare of their host…
Long-term high-cadence measurements of stellar spectral variability are fundamental to better understand stellar atmospheric properties and stellar magnetism. These, in turn, are fundamental for the detectability of exoplanets as well as…
Solar radio spikes are short duration and narrow bandwidth fine structures in dynamic spectra observed from GHz to tens of MHz range. Their very short duration and narrow frequency bandwidth are indicative of sub-second small-scale energy…
We published spectra of phosphine molecules in Venus' clouds, following open-science principles in releasing data and scripts (with community input leading to ALMA re-processing, now benefiting multiple projects). Some misconceptions about…