Stars, as physical systems, are self-gravitating, approximately hydrostatic spheres of plasma in which energy is generated predominantly by thermonuclear fusion in their cores and transported outward by radiation and/or convection. Their structure is governed by the equations of stellar structure, balancing gravity, gas and radiation pressure, and energy transport. Stellar properties such as mass, composition, and rotation determine their internal stratification, nucleosynthetic pathways, luminosity, temperature, and evolutionary tracks. Stars interact with their environments via radiation, stellar winds, and mass loss, and they serve as fundamental sites of element synthesis and key components of galactic and cosmological structure.
Stars die and vanish from sight all the time, but astronomers were puzzled when one that had been stable for more than a decade almost disappeared for eight months.
Astronomy
Aug 22, 2025
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The size of our universe and the bodies within it is incomprehensible to us lowly humans. The sun has a mass that is more than 330,000 times that of our Earth, and yet there are stars in the universe that completely dwarf ...
Astronomy
Aug 20, 2025
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Pictures are the key to new insights in the field of astrophysics. Such images include simulations of cosmic events, which astrophysicists at UZH use to investigate how stars, planets and galaxies came into existence.
Astronomy
Aug 20, 2025
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For the first time, scientists have directly tracked the slow transformation of a dying star over more than a century—revealing it is heating up faster than any other typical star ever observed.
Astronomy
Aug 20, 2025
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A new kind of stellar explosion provides a novel way to probe the distant universe, according to new results published today in Nature Astronomy.
Astronomy
Aug 19, 2025
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The exciting discovery of an extremely rare quadruple star system could significantly advance our understanding of brown dwarfs, astronomers say. These mysterious objects are too big to be considered a planet but also too ...
Astronomy
Aug 19, 2025
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Supernovae appear to our eyes—and to astronomical instruments—as brilliant flashes that flare up in the sky without warning, in places where nothing was visible just moments before. The flash is caused by the colossal explosion ...
Astronomy
Aug 19, 2025
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One of the best places to study stars is inside "open clusters," which are groups of stars that formed together from the same material and are bound together through gravity.
Astronomy
Aug 13, 2025
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Stars are the fundamental building blocks of our universe. Most stars host planets, like our sun hosts our solar system, and if you look more broadly, groups of stars make up huge structures such as clusters and galaxies. ...
Astronomy
Jul 23, 2025
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Lightning might not strike twice, but black holes apparently do. An international group of researchers led by Tel Aviv University astronomers observed a flare caused when a star falls onto a black hole and is destroyed.
Astronomy
Jul 21, 2025
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