Related papers: Precision Millimeter Astrometry of the $\alpha$ Ce…
In this work, we present a new methodology to fit the observed and synthetic spectrum of solar-like stars at millimeter, submillimeter and infrared wavelengths through semiempirical models of the solar chromosphere. We use the…
The field of exoplanetary science has seen discovery rates increase dramatically over recent years, due largely to the data from the Kepler mission. Even so, individual discoveries of planets orbiting nearby stars are very important for…
Regardless of their close proximity, abundance measurements for both stars in {\alpha} Centauri by different groups have led to varying results. We have chosen to combine the abundance ratios from five similar data sets in order to reduce…
The discovery of a planet orbiting around Proxima Centauri, the closest star to the Sun, opens new avenues for the remote observations of the atmosphere and surface of an exoplanet, Proxima b. To date, three-dimensional (3D) General…
[Abridged] Debris discs around main-sequence stars indicate the presence of larger rocky bodies. The components of the nearby binary aCentauri have higher than solar metallicities, which is thought to promote giant planet formation. We aim…
A planet orbiting in the "habitable zone" of our closest neighboring star, Proxima Centauri, has recently been discovered, and the next natural question is whether or not Proxima b is "habitable". Stellar winds are likely a source of…
We investigate the production of axion-like particles (ALPs) in stellar cores, where they interact with electromagnetic fields and electrons, with typical masses between $\mathcal O(0.1)$ and $\mathcal O(10)$ keV. These low-energy ALPs are…
Kepler is a space telescope that searches Sun-like stars for planets. Its major goal is to determine {\eta}_Earth, the fraction of Sunlike stars that have planets like Earth. When a planet 'transits' or moves in front of a star, Kepler can…
The existence of satellite galaxy planes poses a major challenge for the standard picture of structure formation with non-baryonic dark matter. Recently Tully et al. (2015) reported the discovery of two almost parallel planes in the nearby…
We have made velocity observations of the star alpha Cen B from two sites, allowing us to identify 37 oscillation modes with l=0-3. Fitting to these modes gives the large and small frequency separations as a function of frequency. The mode…
We extend our study of the extent of the regions within the $\alpha$ Centauri AB star system where small planets are able to orbit for billion-year timescales (Quarles & Lissauer 2016, AJ 151, 111) to investigate the effects of minimizing…
We perform long-term simulations, up to ten billion years, of closely-spaced configurations of 2 -- 6 planets, each as massive as the Earth, traveling on nested orbits about either stellar component in $\alpha$ Centauri AB. The innermost…
The photospheric radius is one of the fundamental parameters governing the radiative equilibrium of a star. We report new observations of the nearest solar-type stars Alpha Centauri A (G2V) and B (K1V) with the VLTI/PIONIER optical…
Observations of the Earth's exosphere have unveiled an extended envelope of hydrogen reaching further than 10 Earth radii composed of atoms orbiting around the Earth. This large envelope increases significantly the opacity of the Earth to…
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…
Trigonometric parallaxes measured with ground-based telescopes of the RECONS consortium as part of the CTIOPI program are used to search for stars that have either had an encounter with the solar system in the past or will have such an…
Modeling the submillimeter to centimeter emission of stars is challenging due to a lack of sensitive observations at these long wavelengths. We launched an ongoing campaign to obtain new observations entitled Measuring the Emission of…
The very nature of the solar chromosphere, its structuring and dynamics, remains far from being properly understood, in spite of intensive research. Here we point out the potential of chromospheric observations at millimeter wavelengths to…
A search for laser light from the directions of Alpha Centauri A and B was performed by examining 15362 optical, high-resolution spectra obtained between 2004 and 2018. None of the spectra exhibit laser emission lines. The threshold was 10%…
We present a novel approach to model the nearby stars Alpha Cen A & B and Procyon A using asteroseismic and interferometric constraints. Using the VINCI instrument installed at the VLT Interferometer (VLTI), the angular diameters of the…