Tag: exoplanets

How to correct from systematics high-precision photometric data. The study: “Principal component analysis to correct data systematics. Case study: K2 light curves” of A. Petralia (INAF-OAPA) recently appeared on Experimental Astronomy

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Several fields in modern astronomy rely on high-precision photometric data. This is true, in particular, for the search of exoplanets with the method of transits. This method consists in searching very small periodic dimming of stellar emission due to the transit of planets along the line of sight during their orbits. For instance, the transit due to a Hot Jupiter (a gaseous

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Hot Jupiters around young stars. The study: “The GAPS Programme at TNG. XXI. A GIARPS case study of known young planetary candidates: confirmation of HD 285507 b and refutation of AD Leonis b” of I. Carleo (Van Vleck Observatory/INAF-OA Padova) recently appeared on A&A

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The discovery of the first exoplanet in 1995 was a challenge to our knowledge of the architecture of planetary systems. The planet orbiting around the star 51 Peg, in fact, was different than the planets in our Solar System: it was a gaseous giant orbiting at only 0.05 Astronomical Units (A.U., where 1 A.U. is the average distance between Earth

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Thermal inversion in the atmosphere of a ultra-Hot Jupiter. The study: “Neutral Iron Emission Lines from the Dayside of KELT-9b: The GAPS Program with HARPS-N at TNG XX” of Pino L. (INAF/OA Arcetri; University of Amsterdam) recently appeared on ApJ

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Hot Jupiters are gaseous planets orbiting very close to their stars, typically closer than 0.1 Astronomical Units (the average distance between Earth and Sun), and with very short orbital periods of days or even hours. An extreme sub-class of these planets are the ultra-Hot Jupiters. These planets are tidally-locked to their stars (which means that they show always the same

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Planets with ultra-short period. The study: “An ultra-short period rocky super-Earth orbiting the G2-star HD 80653” of G. Frustagli (INAF – Astronomical Observatory of Brera) recently appeared on A&A

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The “Ultra-Short Period” (USP) exoplanets have very close orbits and orbital periods shorter than one day. These planets typically have a radius smaller than 2 Earth radii and a terrestrial composition, sometime with an excess of iron.   Four hypotheses have been made to explain the formation and evolution of USP planets. The main hypothesis is that these planets originate

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Hot super-Earths with an hydrogen-rich atmosphere. The study: “Hot Super-Earths with Hydrogen Atmospheres: A Model Explaining Their Paradoxical Existence” of D. Modirrousta-Galian (INAF-OAPA) recently appeared on ApJ

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“Super-Earths” are rocky exoplanets with a mass between that of Earth and Uranus. Some of these planets may also have a close orbit around the parent star. For instance, the super-Earth 55 Cancri e has a mass of 8.6 Earth masses and it orbits at a distance of 0.016 AU (Astronomical Unit, which is the average distance between Earth and

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TESS finds an exoplanets around a 40 million years old star. The study: “A possibly inflated planet around the bright young star DS Tucanae A” of S. Benatti (INAF-OAPA/INAF-Padova) recently appeared on A&A

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The final architecture of a planetary system is the result of a complex interplay between several processes, such as the dispersion of the protoplanetary disk from which the planetary system formed, and the gravitational interaction between the newborn planets. Besides, these processes can be affected by the environment and by their central star. One of the most important process dictating

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Evaporating planets. The study: “Photo-evaporation of close-in gas giants orbiting around G and M stars” of D. Locci (INAF-OAPA) recently appeared on A&A

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The stellar magnetic activity can produce an important emission of energetic X-ray and UV radiation. This emission is typically variable, both because the magnetic activity changes over short time scales, and because it decreases during stellar evolution. For instance, solar-type stars in the pre-main sequence phase (i.e. younger than 30 million years) are thousand times brighter in X-rays than main

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Stellar chemical composition and planetary formation. The study “Connecting substellar and stellar formation. The role of the host star’s metallicity” of J. Maldonado (INAF-OAPA) recently appeared on A&A

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To date, about 4000 exoplanets (planets orbiting around other stars) have been confirmed. Stars hosting planets and sub-stellar companions span a wide range of stellar parameters and even evolutionary phases. For this reason, several studies have been focused on the connection between stellar parameters and the possibility to host planets or sub-stellar companions such as brown dwarfs.   In particular,

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A new super-Earth around an M star. The study: “HADES RV program with HARPS-N at the TNG. IX: A super-Earth around the M dwarf Gl 686” of L. Affer (INAF-OAPA) recently appeared on A&A

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Low mass star (in particular M-type star, with a mass between 0.075 and 0.5 solar masses) are typical targets for the search and study of exoplanets. In these stars, in fact, the radial velocity method is more efficient than in stars with higher mass. Radial velocity consists in detecting periodic oscillations in the stellar spectra due to the motion of

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