Galaxies are gravitationally bound, large-scale astrophysical systems composed primarily of dark matter, stars, stellar remnants, gas, and dust, often embedded in extended dark matter halos. They exhibit diverse morphologies, including spiral, elliptical, and irregular types, and span mass scales from roughly 10⁷ to over 10¹² solar masses. Their internal dynamics are governed by gravity and angular momentum distribution, with baryonic components organized into disks, bulges, and halos, and frequently hosting central supermassive black holes. Galaxies are fundamental units of cosmic structure formation, participating in hierarchical assembly, mergers, and interactions within larger environments such as groups, clusters, and filaments of the cosmic web.
Astronomers have long puzzled over how some massive galaxies stop forming stars and remain dormant for billions of years—even when they still contain gas that could, in principle, fuel new stars.
Astronomy
Jan 9, 2026
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A recent study provides answers to three seemingly disparate yet pressing cosmic dawn puzzles. Specifically, the authors show how dark stars could help explain the unexpected discovery of "blue monster" galaxies, the numerous ...
Astronomy
Jan 8, 2026
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Astronomers using W. M. Keck Observatory on Maunakea, Hawaiʻi Island have uncovered the largest and most extended stream of super-heated gas ever observed flowing from a nearby galaxy, providing the clearest evidence yet ...
Astronomy
Jan 8, 2026
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They're called ghost particles for a reason. They're everywhere—trillions of them constantly stream through everything: our bodies, our planet, even the entire cosmos. These so-called neutrinos are elementary particles that ...
Astronomy
Jan 8, 2026
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Galaxy clusters are formed by a dense packing of many galaxies, making them the most massive structures in the universe. Their progenitors, protoclusters, show these galaxies in their infancy, offering a window to study how ...
Astronomy
Jan 8, 2026
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Astronomers have created a detailed forecast of where they expect to observe future stellar explosions in a nearby galaxy, opening a new window into how exploding stars shape the cosmos. Focusing on M33, a spiral galaxy about ...
Astronomy
Jan 7, 2026
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Astronomers from Serbia and Russia have conducted deep optical observations of a cloud of neutral atomic hydrogen, designated FAST J0139+4328. Results of the observational campaign, published December 31 on the arXiv preprint ...
After combing through NASA's James Webb Space Telescope's archive of sweeping extragalactic cosmic fields, a small team of astronomers at the University of Missouri says they have identified a sample of galaxies that have ...
Astronomy
Jan 6, 2026
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Astronomers have captured the most detailed look yet at faraway galaxies at the peak of their youth, an active time when the adolescent galaxies were fervently producing new stars.
Astronomy
Jan 6, 2026
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Scientists at the University of Missouri have identified a small group of unusual objects in the early universe. Using NASA's James Webb Space Telescope (JWST), Haojing Yan and his team at Mizzou's College of Arts and Science ...
Astronomy
Jan 6, 2026
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