Dischi protoplanetari in Orion A non mostrano effetti ambientali sulla quantità di materia che accrescono sulla stella centrale I dischi protoplanetari sono strutture a forma di disco osservate attorno a stelle giovani, tipicamente con un’età inferiore ai 10 milioni di anni. Sono oggetti di grande interesse scientifico per vari motivi, principalmente perché rappresentano la struttura in cui si formano
Scoperto nel superammasso stellare Westerlund 1 un alone di stelle in espansione asimmetrica mentre il nucleo sembra contrarsi Gli ammassi stellari sono un prodotto diretto del processo di formazione stellare: se infatti dalla contrazione gravitazionale di una nube si forma un numero sufficientemente alto di stelle, queste rimangono legate dalla reciproca attrazione gravitazionale per almeno alcuni milioni di anni.
L’abbondanza di elementi chimici pesanti nelle regioni di formazione stellare influenza l’evoluzione delle stelle e dei loro dischi protoplanetari? Nuovi indizi da uno studio sulla regione Sh2-284 Nei primi milioni di anni di vita, le giovani stelle sono spesso circondate da un disco di gas e polveri chiamato “disco protoplanetario”. Come suggerisce il nome, è la struttura da cui
A new study on the low mass stellar population of the star forming region Corona Australis shed light on the formation of brown dwarfs In recent years, several studies of star-forming regions near the Sun have revealed that a significant fraction of the stellar population of the Milky Way consists of brown dwarfs—objects whose cores do not reach the
The star-forming regions can differ significantly from one another, particularly in terms of the population of massive stars (with masses exceeding about 10 solar masses) and stellar density (defined as the number of stars per unit volume). These aspects can vary drastically from one region to another. Such differences are extremely important, as massive stars create environments dominated by high-energy
Today in the Milky Way, star formation typically occurs in low-mass environments. Young star clusters (e.g., younger than 10 million years), in fact, typically have a mass of a few hundred solar masses. Nevertheless, our Galaxy hosts a few very massive star-forming regions that can produce tens to hundreds of thousands of stars, including some of the most massive stars
The formation of stars and planets results from the complex interplay of various factors and agents: the collapse of the cloud due to its own gravitational force, its internal turbulence and magnetic effects, the evolution of star clusters formed within, and the interactions among young stars within these clusters, as well as the influence of their radiation on the surrounding
Several questions about the star formation process are still debated. For instance, we know that stars form from the gravitational contraction of clouds of gas and dust, called “molecular clouds,” since they are mainly made of molecular hydrogen. Mainly thanks to observations from the Herschel satellite, we also know that most star formation occurs in long filaments embedded in these
After their formation, during the first few million of years (how many? it depends on the mass: the larger the stellar mass the faster is their evolution) stars continue to contract under their the action of their own gravity, rising their temperature and density. During this phase, their nuclei have not started yet the thermonuclear reactions that will power the
A supernova is the final act of the evolution of a massive star. These spectacular explosions are among the most energetic events we observe in the Universe, and they can seriously impact the surrounding environment. In particular, during the expansions of the supernova remnants, which are the expanding clouds produced by supernova explosions, the process of star formation in the
