Tag: exoplanets

A super-Earth for the star GJ 740. The study: “A super-Earth on a close-in orbit around the M1V star GJ 740. A HADES and CARMENES collaboration” of B. Toledo-Padrón (IAC) recently appeared on Astronomy & Astrophysics

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In the last years, stars of spectral class M (which are stars with effective temperatures between 2400 and 3700 K and masses between 0.08 and 0.45 solar masses) have been extensively observed for the search of exoplanets. This both because they are the most abundant class of stars in the Galaxy, and because the low star/planet mass ratio, compared to

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Two Neptunians for a young star. The study: “The GAPS Programme at TNG XXVIII. A pair of hot-Neptunes orbiting the young star TOI-942” of I. Carleo (Wesleyan University/INAF-OAPd) recently appeared on su A&A)

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The exoplanetary systems discovered so far (3212 systems with a total of 4331 exoplanets, as reported by https://exoplanets.nasa.gov/ on January 21st 2021) show a great variety of systems architecture, with some configurations which are completely different than that of our Solar System. This variety of architectures is a challenge for studies of the planetary formation process and all mechanisms that contribute in

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Photospheric spots and planetary transits. The study: “Correcting the effect of stellar spots on ARIEL transmission spectra” of G. Cracchiolo (UNIPA, INAF-OAPA) appeared on MNRAS

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A “transit” occurs when we observe a planet moving across the disc of its star. Thus, during the transit the planet obscures a small portion of its star, slightly reducing its luminosity. While in the Solar System the only planets we can observe transiting in front of the Sun are Mercury and Venus, transits is still the most efficient method

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Chemical composition and elevation of the atmosphere of WASP-121b. The study: “Atmospheric Rossiter-McLaughlin effect and transmission spectroscopy of WASP-121b with ESPRESSO” of F. Borsa (INAF-OA Brera) recently appeared on A&A)

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Ultra-hot Jupiters are gaseous planets orbiting at close distances from their central stars, with rotation periods shorter than 3 days. Their atmospheres are thus heated, more than 2000 degrees, by the incident radiation emitted by the central star. For this reason, the atmospheres of ultra-hot Jupiters shows peculiar properties compared with planets of other types. For instance, they are affected

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The fraction of exoplanets as a function of stellar metallicity. The study: “HADES RV Programme with HARPS-N at TNG XII. The abundance signature of M dwarf stars with planets” of J. Maldonado (INAF-OAPA) recently appeared on A&A

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The mechanisms involved in the formation of planets are still not completely understood. The most widely accepted model that describe the formation of gaseous planets is the core-accretion model. In this paradigm, the formation of these planets starts with the formation of a large rocky core by the coagulation of planetesimals, followed by the accretion of a large gaseous envelope

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An Hot Jupiter that may not be there. The study: “The GAPS Programme at TNG. XXVII. Reassessment of a young planetary system with HARPS-N: is the hot Jupiter V830 Tau b really there?” of M. Damasso (INAF-OATo) recently appeared on A&A

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Some of the exoplanets known so far belong to classes that do not exist in our Solar System. For instance,  the class of the Hot Jupiters, i.e., gaseous giant planets orbiting at close distances from their stars (typically less than 0.5 AU, Astronomical Unit, where a 1 AU is the average distance between Sun and Earth, about 150 million km).

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A super-Earth orbiting around an old M star. The study: “GJ 357 b. A super-Earth orbiting an extremely inactive host star” of Modirrousta-Galian (UNIPA/INAF-OAPA) recently appeared on A&A

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Despite theoretical models predict a large abundance of Earth-like planets in our Galaxy, the family of the 4284 planets discovered so far (updated at 2020/9/25, credits: NASA) counts relatively a few of such a planets. This is clearly an observational bias, due to the fact that the methods used to detect planets are not sensitive to small planets. For this

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Neptunians and super-Earths in systems with “cold” Jupiters as test for planetary migration theories. The study: “The GAPS programme at TNG. XXIV. An eccentric Neptune-mass planet near the inner edge of the BD-11 4672 habitable zone” of D. Barbato (UniTo/OATo) and M. Pinamonti (OATo) recently appeared on A&A

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The architecture of planetary systems is result from both the planet formation process and a complex mechanism of radial migration of planets. This has occurred also in the Solar System, whose final architecture resulted from the migration of the gaseous giants. In particular, the theories describing the formation and migration of super-Earths and Neptunian planets predict different configurations of the

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Exoplanets with extended evaporating atmospheres. The study: “The GAPS programme at TNG. XXII: The GIARPS view of the extended helium atmosphere of HD 189733 b accounting for stellar activity” of G. Guilluy (UniTO/INAF-OATo) recently appeared on A&A

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The number of known exoplanets discovered so far (4197 planets, updated at 2020/August/4th, from NASA) is large enough to allow us to study their global properties. One of these properties, still lacking a proper explanation, is the so-called “Neptunian desert”, e.g. the lack of intermediate planets with orbital periods shorter than 3 days. One of the hypotheses that can explain the Neptunian

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Atmosphere and habitability in terrestrial planets. The study: “A systematic study of CO2 planetary atmospheres and their link to the stellar environment” of A. Petralia (INAF-OAPA) recently appeared on MNRAS

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Terrestrial planets are common in the Milky Way. It has been estimated, in fact, that at least 30% of stars in the Solar neighborhood host a terrestrial planet, and this fraction increases to 40% considering the habitable zone around all M stars (e.g. stars with effective temperature between 2400 and 3700 degrees) of the Galaxy. The habitable zone is defined

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