Category: Ricerca

X-ray analysis of the Wolf Rayet of Westerlund 1. The study: “EWOCS-II: X-ray properties of the Wolf-Rayet stars in the young Galactic super star cluster Westerlund 1” of K. Anastasopoulou (INAF-OAPA/CfA) appeared on A&A

Ricerca

Massive stars live short and violent lives. Mainly during the later stages of their evolution, these stars undergo significant changes in their structure and lose a large fraction of their initial mass into the surrounding environment as stellar winds. In particular, during the Wolf-Rayet phase, which lasts only a few hundred thousand years, massive stars eject their outer layers, which

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New Study on Thermalization of X-IFU Instrument’s Ultra-Thin Al-Coated Filters led by N. Montinaro (INAF – OAPA)

Ricerca

X-ray astronomy is aimed at the understanding of the high-energy phenomena occurring in the Universe. Since our atmosphere blocks the X-ray photons, this branch of astronomy relies on observations made with satellites. In the past 30 years, X-ray astronomical observations had two main actors: the NASA satellite Chandra and XMM/Newton of the European Space Agency (ESA). The future, instead, goes

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Ammonia and water in the atmosphere of the warm Neptune HAT-P-11 b. The study described in the paper: “The GAPS Programme at TNG LV. Multiple molecular species in the atmosphere of HAT-P-11 b and review of the HAT-P-11 planetary system” of M. Basilicata (Università di Tor Vergata)

Ricerca

One of the most interesting possibilities offered by the research on exoplanets is the ability to study types of planets that are not present in the Solar System. Among these are the “hot” and “warm” Neptunes. These are planets the size of Neptune that orbit very close to their stars (with an orbital period shorter than 10 days), with an

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Fifteen spectral indices to select planetary-mass objects. The study: “Spectral characterization of young LT dwarfs” of L. Piscarreta (CENTRA, ESO) appeared on A&A

Ricerca

Understanding the star formation process also means acquiring a full understanding of its final products, such as the mass distribution of the stars formed in a single star-formation event (which is the initial mass function). In particular, it is still not clear what the dominant mechanism responsible for the formation of the less massive sources is: the planetary-mass objects, with

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A study on the processes responsible for the acceleration of particles in shocks. The study: “Individual particle approach to the diffusive shock acceleration. Effect of the non-uniform flow velocity downstream of the shock” of O. Petruk (INAF-OAPA) appeared on A&A

Ricerca

Our planet is constantly bombarded by highly energetic particles known as ‘cosmic rays‘. The spectrum of cosmic rays up to energies of 1015 electronvolts (eV) is formed by the sources in our Galaxy, while particles with observed energies up to 1021 eV should have extra-galactic origin. The cosmic ray spectrum follows a power law, meaning that the flux of particles with a given

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Four planets (at least) for two stars. The study: “The GAPS Programme at TNG. LIII. New insights on the peculiar XO-2 system” of A. Ruggieri (Università di Padova) appeared on A&A

Ricerca

Every sci-fi enthusiast, especially Star Wars fans, has wondered whether planets orbiting two stars, like Tatooine, can exist in reality. This is actually an important question in astronomy: It has been estimated that in the Milky Way, one-third of low-mass stars are in binary systems. Therefore, to fully understand the population of planets in our Galaxy, it is necessary to

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Water or stellar activity? The study: “A reanalysis of the LHS 1140 b atmosphere observed with the Hubble Space Telescope” of A. Biagini (INAF-OAPA/UNIPA) appeared on MNRAS

Ricerca

To date, April 1st 2024, 74.4% of the 5602 confirmed exoplanets have been discovered through transit observations. This technique involves observing the imperceptible and periodic dimming of the luminosity of the central star during each transit of their planets in front of the star with respect to our line of sight. Furthermore, by comparing spectroscopic observations of the star outside

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A first homogeneous study on the dynamics of stellar clusters. The paper: “The Gaia-ESO Survey: 3D dynamics of young groups and clusters from GES and Gaia EDR3” of N. J. Wright (Keele University) recently appeared on MNRAS

Ricerca

Stars do not form in isolation. During gravitational collapse, molecular clouds fragment, forming a large number of stars. For this reason, young stars are typically observed as members of star clusters or associations.   In the past decade, the study of stellar clusters in the Milky Way has undergone a revolution, thanks to observations from the Gaia satellite of the

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TOI-4515 b, a “warm Jupiter” with a turbulent story. The study: “The GAPS programme at TNG L. TOI-4515 b: An eccentric warm Jupiter orbiting a 1.2 Gyr-old G-star” of I. Carleo (Instituto de Astrofísica de Canarias) recently appeared on A&A

Ricerca

The study of the orbital parameters of exoplanets can shed light on their past. An important quantity in this context is the eccentricity of elliptical orbits, which is the ratio between the distance of the foci over the major semiaxis. Eccentricity is equal to zero when the ellipse degenerates into a circle or equal to one when it degenerates into

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Synthesis of spectra of exoplanetary atmospheres externally irradiated by X/UV radiation. The study: “Signatures of X-ray dominated chemistry in the spectra of exoplanetary atmospheres” of D. Locci (INAF – OAPA) appeared on PSJ

Ricerca

One of the lessons we have learned after two decades of exoplanetary science, primarily from the diversity of exoplanets discovered to date, is that various properties of exoplanets depend on the characteristics and evolution of their parent stars. Specifically, stellar X-ray and UV radiation can impact the chemical and physical properties of planetary atmospheres. While UV radiation is primarily absorbed

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