Tag: exoplanets

As X/UV radiation affects the chemistry of planetary atmosphere. The study: “Extreme-ultraviolet- and X-Ray-driven Photochemistry of Gaseous Exoplanets” of D. Locci (INAF – OAPA) recently appeared on PSJ

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Some of the 4903 exoplanets discovered and confirmed so far (https://exoplanets.nasa.gov/) orbit very close to their stars. We learnt with the very first planet discovered around a star different than the Sun (51 Pegasi b, discovered in 1995) that planets with very close orbits are possible in nature. 51 Pegasi b, in fact, orbits at about 0.05 Astronomical Units (AU,

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Discovered the first planetary system with planets both in equatorial and polar orbits revealed by the study: “The Rossiter-McLaughlin effect revolutions: an ultra-short period planet and a warm mini-Neptune on perpendicular orbits” of V. Bourrier (Observatoire Astronomique de l’Université de Genève), appeared on A&A

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The study of the architecture of planetary systems, and in particular that of the spin-orbit angle (which is the inclination of the planetary orbit with respect to the stellar rotation axis) can unveil important details on the dynamical evolution of planetary systems. In particular, young planets typically migrate radially, changing their distance to the host star and interacting with the

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The study: “Estimating Magnetic Filling Factors from Simultaneous Spectroscopy and Photometry: Disentangling Spots, Plage, and Network” of T. W. Milbourne (Harvard University), recently appeared on ApJ, present two new methods that allow astronomers to estimate the filling factor of magnetic active regions

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About 20% of the exoplanets discovered so far (October 2021) were found with measurements of radial velocity (data from https://exoplanets.nasa.gov/). This method is based on spectroscopic observations of stars with planets, from which it is possible to measure the Doppler effect produced by periodic oscillations of the star, due to the gravitational attraction between star and planet along the orbit of

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Published in A&A the paper describing the catalog of the candidate targets for the PLATO mission: “The all-sky PLATO input catalogue” of M. Montalto (Unipd/INAF-OAPd)

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According to the data released by NASA, to date (2021 October 1st) we have confirmed 4525 exoplanets in 3357 planetary systems. The vast majority of these planets (75%) were discovered with the methods of transits, while about 20% with that of radial velocity. With the former technique, planets are discovered when they transit in front of their stars along our line

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The hot Jupiter WASP-33b targeted by HARPS-N. The study: “The GAPS Programme at TNG. XXXI. The WASP-33 system revisited with HARPS-N” of F. Borsa (INAF – AO of Brera) recently appeared on A&A

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Hot Jupiters are gaseous giant planets that orbit very close to their stars (within a typical distance of less than 0.1 Astronomical Units, AU, where 1 AU is the average distance between Earth and Sun, about 150 million of km). These planets are of great interest for astronomers both because of the effects due to the intense incident stellar radiation,

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A super-Earth for the star GJ 9689. The study: “HADES RV programme with HARPS-N at TNG. XIV. A candidate super-Earth orbiting the M-dwarf GJ 9689 with a period close to half the stellar rotation period” of J. Maldonado (INAF-OAPA) recently appeared on A&A

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M stars are the most common stars in the Universe. They have a mass ranging between 0.6 and 0.08 Solar masses in the main sequence, and an effective temperature ranging between 3900 K and 2400 K. In these stars, the signals due to the presence of planets, such as radial velocity (periodic oscillations of the star from its rest position

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A young and low-density planet for DS Tucanae A. The study: “Constraints on the mass and atmospheric composition and evolution of the low-density young planet DS Tuc A b” of S. Benatti (INAF – OAPa) recently appeared on A&A

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The study of planets orbiting around young stars (younger than 100 million years) can help astronomers understanding the physical processes setting the early evolution of planetary systems. However, young stars are typically characterized by rapid rotation and intense magnetic activity, phenomena which produce photometric and spectroscopic signals that can mimic and confuse those due to the presence of planets. It

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A sub-Neptunian exoplanet around the star GJ 720 A. The study: “HADES RV Programme with HARPS-N at TNG XIII. A sub-Neptune around the M dwarf GJ 720 A” of E. González-Álvarez (CSIC-INTA) recently appeared on A&A

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About 19.3% of the 4001 exoplanets confirmed to date were discovered with the technique of the radial velocity (from https://exoplanets.nasa.gov/). This method consists in using time series of spectroscopic observations in order to measure the periodic oscillations of the position of stars due to the presence of orbiting exoplanets. In fact, in a planetary system both the planets and the

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The chemical composition of the Hot Jupiter HD 209458b tells us about its history. The study: “Five carbon- and nitrogen-bearing species in a hot giant planet’s atmosphere” of P. Giacobbe (INAF – OATo) recently appeared on Nature

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The discovery of the first planet orbiting around another star occurred in the 1995, thanks to the astronomers Michel Mayor and Didier Queloz. This discovery set a milestone in astronomy both because it was the first observational confirmation of the existence of planets orbiting around other stars (in this case 51 Pegasi), and because of the nature of this exoplanet. It

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Composition of a sub-neptunian exoplanet with TESS and ESPRESSO. The study: “A sub-Neptune and a non-transiting Neptune-mass companion unveiled by ESPRESSO around the bright late-F dwarf HD 5278 (TOI-130)” of A. Sozzetti (INAF-OATo) recently appeared on A&A

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The NASA satellite Transiting Exoplanet Survey Satellite (TESS) it’s one of the most effective telescopes to search for exoplanets. TESS is designed to find exoplanets with the transits method, e.g. by observing the periodic occultations of stars by their planets during their orbits. To date, about 27% of the exoplanets discovered with TESS belong to the class of the sub-neptunians. These planets have a

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