Tag: exoplanets

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

Ricerca

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

» Read more
, , , ,

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

Ricerca

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

» Read more
, , ,

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

Ricerca

“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

» Read more
, , ,

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

Ricerca

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

» Read more
, ,

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

Ricerca

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

» Read more
, , , , ,

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

Ricerca

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,

» Read more
, , ,

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

Ricerca

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

» Read more
, , , , , , , ,

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

Ricerca

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

» Read more
, , , , ,

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

Ricerca

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

» Read more
, , , , , , ,

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

Ricerca

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.

» Read more
, , , , , , ,
1 … 3 4 5 6 7