Tag: exoplanets

Planets migrations and impacts. The study: “A giant impact as the likely origin of different twins in the Kepler-107 exoplanet system” of A. S. Bonomo (INAF– OA di Torino) recently appeared on Nature Astronomy

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Exoplanets with a radius smaller than 3 Earth radii span a wide range of characteristics. In fact, both low density sub-Neptunian and high-density Earth- and Mercury-like planets have been observed with such a radius. This diversity suggests that these planets, despite being formed in a similar way, followed different evolutionary patterns depending on the characteristics of their host stars, the

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Three super-Earth for a star. The study “Masses and radii for the three super-Earths orbiting GJ 9827, and implications for the composition of small exoplanets” of K. Rice (University of Edinburgh) published by MNRAS

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Super-Earths are exoplanets with radii between that of the Earth and that of Neptune (about 4 times the radius of the Earth), and with orbital periods smaller than 100 days. Although the Solar System does not host a similar planet, super-Earths are actually common in the Milky Way. This type of exoplanet is also interesting since they populate a gap

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Artificial Intelligence applied to astrophysics. The paper “ExoGAN: Retrieving Exoplanetary Atmospheres Using Deep Convolutional Generative Adversarial Networks” of T. Zingales (UCL, INAF – OAPA) published on AJ

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In the last few years, many space missions and ground-based surveys, discovered more than 4000 exoplanets, especially using the transit and radial velocity methods. These two methods combined, give us a first estimation of the bulk density of the planets. In order to have a deeper understanding on the planetary characteristics and history, we also need to study their atmospheres.

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Planets in binary systems. The study: “The HADES RV Programme with HARPS-N@TNG VIII. Gl15A: A multiple wide planetary system sculpted by binary interaction” of M. Pinamonti (INAF-OATo) published on A&A

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In our Galaxy, a large fraction of stars is part of binary systems. For instance, the study of Duquennoy & Mayor (1991) suggests a binary fraction of 57% for solar type stars. A slightly smaller binary fraction is expected for less massive stars. Among pre-Main Sequence stars, several binary systems are known to host a circumbinary disk. These disks are

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A sub-Neptunian planet discovered around a G9 star. Published on MNRAS: “K2-263 b: a 50 d period sub-Neptune with a mass measurement using HARPS-N” of A. Mortier (University of St. Andrews)

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The search of exoplanets relies mainly on two techniques: transits and radial velocity. With the former method exoplanets are revealed thanks to small and periodic dimming of the light of stars when their planets orbit across the stellar disk, producing a small eclipse. The method of radial velocity consists in revealing the oscillations of stars around the center of mass

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The first study in the framework of GIARPS rules out the existence of a hot Jupiter. The study: “Multi-band high resolution spectroscopy rules out the hot Jupiter BD+20 1790b. First data from the GIARPS Commissioning” of I. Carleo (INAF – OAPd) recently published on A&A

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Most of the exoplanets identified so far have been discovered by using two techniques: transits and radial velocity. In particular, radial velocity method consists in detecting the oscillations of stars around the center of mass common with their planetary systems by measuring periodic doppler shifts in high-resolution spectra. The main difficulty with this technique is the fact that stellar activity,

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The orbital inclination of 5 exoplanets is presented in teh study “The GAPS programme with HARPS-N at TNG XVI. Measurement of the Rossiter–McLaughlin effect of transiting planetary systems HAT-P-3, HAT-P-12, HAT-P-22, WASP-39, and WASP-60” of L. Mancini (University of Rome Tor Vergata), recently published by A&A

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The discovery of hot Jupiters (Jupiter-like exoplanets in close orbits) has changed our view of planet formation. It is still debated whether hot Jupiters form in the present-day orbits or they form at large distances from their star and then they migrate inward. (e.g. Maldonado et al. 2018).   Planetary migration can be induced by several effects, mainly interaction between

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ARIEL selected as next M4 mission by the ESA Space Programme Committee

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In the last years the number of known exoplanets has grown quickly thanks to missions such as Kepler and CoRoT and instruments such as HARPS-N, mounted on the Telescopio Nazionale Galileo, which are designed to identify exoplanets with the method of transits or radial velocity. We have understood now that the presence of exoplanets is a common features in stars

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A new super-Earth discovered thanks to Harps-N. The study “HADES RV Programme with HARPS-N at TNG. GJ 3942 b behind dominant activity signals” of M. Perger published by A&A

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The analysis of radial velocity is one of the two main methods used to detect exoplanets. This method consists in measuring the Doppler effect on stellar spectra deriving the velocity component along the line of sight (the radial velocity). If the star has a planet, they both orbit around the common center of mass,  producing periodic oscillations of the osberved

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