Category: Ricerca

A search for binary systems with GES. The study “The Gaia-ESO Survey: double, triple, and quadruple-line spectroscopic binary candidates” by T. Merle recently appeared on A&A

Ricerca

The study of binary systems plays an important role in several fields of astronomy such as stellar evolution and galactic archeology since it allows direct measurements of stellar parameters such as masses, radii, and luminosities.   Multiple stellar systems have typically small angular separation and thus they are not resolved by direct imaging. In these cases spectroscopy is a powerful tool

» Read more
, , , ,

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

Ricerca

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

» Read more
, , , , , , ,

The study: “XMM-Newton imaging of V1818 Orionis: a young stellar group on the eastern edge of the κ Ori ring” of I. Pillitteri (INAF-OAPA) recently published by A&A

Ricerca

The Orion Molecular Cloud is likely the best target for studying star formation. In the past few million years, in fact, this cloud formed thousands stars over a wide range of stellar masses and in several episodes with different characteristics: From isolated low mass stars to populated and massive stellar clusters; from star formation from self-collapsing clouds to triggered star

» Read more

Star formation and X-rays. Published by MNRAS the study: “Röntgen spheres around active stars” of D. Locci (OAPA/UNIPA)

Ricerca

“Stars form from the gravitational contraction of molecular clouds”: This is the basic concept of star formation process. However, the reality is much more complicated than this. The process that cause large (typically tens of light years) and cold (few degrees K) clouds of gas and dust to collapse into stars consists in a complex interplay between gravity, gas turbulence,

» Read more

A detailed view of the accretion process onto pre-Main Sequence stars. Published on A&A the study: “Redshifted X-rays from the material accreting onto TW Hydrae: Evidence of a low-latitude accretion spot” of C. Argiroffi

Ricerca

Pre-Main Sequence stars (which are still contracting and whose nucleus is still not hot and dense enough to ignite the nuclear fusion) are often observed surrounded by a disc of gas and dust called protoplanetary discs. Among the reasons why it is crucial to study these discs, it must be cited the fact that they are the environment of planet

» Read more

OAPA astronomers participated at the study: “Laboratory unraveling of matter accretion in young stars” of G. Reves published by Science Advances

Ricerca

Pre-Main Sequence stars are young stars (solar type pre-main sequence stars are younger than about 30 million years), that are often observed surrounded by a disc of haas and dust called “protoplanetary discs”. These discs can actively accreting matter onto the central star, with a complex process resulting from a complicated interplay between the gas of the disc and the

» Read more
, , , , ,

Archeo-astronomy with the Gaia-ESO Survey. “The Gaia-ESO Survey: matching chemodynamical simulations to observations of the Milky Way” of B. B. Thompson recently published

Ricerca

Not all the archaeologists do their studies digging holes or classifying artifacts in dusty museums… some of them actually use telescopes…   Galactic archeology is a branch of astronomy dedicated to the study of the formation and evolution of the components of our Galaxy (bulge, bar, disc and halo) by analyzing ages, dynamics, and chemical abundances of stars. Not an easy

» Read more
, ,

A new super-Earth discovered with HARPS-N: Published by A&A the research: “HADES RV Programme with HARPS-N at TNG. V: A super-Earth on the inner edge of the habitable zone of the nearby M dwarf GJ 625” of A. Suárez Mascareño

Ricerca

The family of the potentially habitable exoplanets named “super-Earths” (rocky planets with a mass ranging between 2 and 10 times that of the Earth), counts a brand new member.   On Astronomy & Astrophysics has been recently published the study “HADES RV Programme with HARPS-N at TNG. V: A super-Earth on the inner edge of the habitable zone of the

» Read more

Cycles of chromospheric and coronal activity. Published by A&A “Fifteen years in the high-energy life of the solar-type star HD 81809” of S. Orlando (INAF-OAPA)

Ricerca

An observation in X-rays of a single star 15 years long…The objective? The understanding of the coronal cycle in stars: do solar-like stars have a coronal cycle such as the one of our Sun?   The term “solar activity” includes all those phenomena observed in the solar photosphere, chromosphere, and corona related to the solar magnetic field, such as sunspots,

» Read more

NASA/Chandra press release about the simulation made by an OAPA/UNIPA/CfA team of the nova V745 Sco

Ricerca

A recent press release has appeared on the NASA/Chandra website (link), dedicated to the binary system V745 Sco and the model developed by S. Orlando (INAF-Astronomical Observatory of Palermo), M. Miceli (University of Palermo) e J. J. Drake (Harvard-Smithsonian Center for Astrophysics, US), which explains the nova explosion occurred on February 6th 2014.   V745 Sco is a binary system composed

» Read more
1 … 23 24 25 26 27 … 30