On June 2019, the panel for the evaluation of the proposals for observations with the NASA telescope Chandra, operating in the X-rays, which met up in Boston, has approved the Large Project: “Star formation in starburst: a deep ACIS-I observation of Westerlund 1“, led by the astronomer Mario Giuseppe Guarcello – INAF Astronomical Observatory of Palermo. More details on the
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Stellar X-ray emission arises from their corona, which is the outer part of stellar atmosphere with low-density high-temperature (up to million degrees) plasma. Even if we lack a fully understanding of the details, we know that the intensity of stellar X-ray emission depends on the intensity and the morphology of stellar magnetic field. The interior of stars of FGK
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Most of the stars, mainly the low mass stars, produce their own magnetic field in their interior. The interaction between the magnetic field and stellar plasma is the cause of phenomena such as photosperic spots, faculae, protuberances, coronal mass ejections, and flares. The study of this activity is important both because it reveals how intense magnetic fields interact with high-temperature
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OB associations are objects of great importance, since they contain a rich population of OB stars. Despite their paucity, OB stars have a strong impact on the evolution of their parental clouds, nearby stars, and the whole Galaxy. For instance, their intense UV emission affects the evolution of the parental cloud and the star formation process in it, sometimes triggering
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What remains after a supernova explosion, which is among the most energetic phenomena in the Universe, is an expanding cloud interacting with the surrounding interstellar medium (the “supernova remnants”) and a compact object produced by the contraction of the nucleus of the progenitor star. Given its proximity to the Sun (“only” 945 light years), the Vela supernova remnant is one
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di Mario Giuseppe Guarcello ( segui mguarce) È stato pubblicato sul sito del satellite Chandra della NASA un articolo (link) interamente dedicato agli studi INAF-OAPA/CfA della regione di formazione stellare nota come Nebulosa dell’Aquila o M16, contenente l’ammasso stellare NGC 6611, realizzato con vari telescopi operativi in diverse bande dello spettro elettromagnetico, tra cui il satellite Chandra della
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During their short existence lasting only few million years, massive stars (more massive than 8 solar masses with spectral type O and B-early) strongly affect the surrounding environment thanks to their intense UV radiation and stellar winds. A single O star, in fact, can loose about 10-6 solar masses of gas in a wind reaching velocities of 1600–2500 km s−1 (Stevens & Hartwell, 2003).
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di Mario Giuseppe Guarcello ( segui mguarce) A recent study by a team of researchers of INAF-Astronomical Observatory of Palermo, the University of Palermo, and the University of Madrid, recently published on the Astrophysical Journal, shows that enormous flares in the young stars in Orion are due to large magnetic loops connecting the stars and their protoplanetary disks,
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