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.
Intense radiation emitted by active supermassive black holes—thought to reside at the center of most, if not all, galaxies—can slow star growth not just in their host galaxy, but also in galaxies millions of light-years away, ...
Astronomy
Feb 18, 2026
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A team of 48 astronomers from 14 countries, led by the University of Massachusetts Amherst, has discovered a population of dusty, star-forming galaxies at the far edges of the universe that formed only a billion years after ...
Astronomy
Feb 17, 2026
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Astrophysicists from the University of Waterloo have observed a new jellyfish galaxy, the most distant one of its kind ever captured. Jellyfish galaxies are named for the long, tentacle-like streams that trail behind them. ...
Astronomy
Feb 17, 2026
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In 2014, a NASA telescope observed that the infrared light emitted by a massive star in the Andromeda galaxy gradually grew brighter. The star glowed more intensely with infrared light for around three years before fading ...
Astronomy
Feb 14, 2026
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The existence of massive, elliptical galaxies in the early universe has puzzled astronomers for two decades. An international team led by Nikolaus Sulzenauer and Axel Weiß from the Max Planck Institute for Radio Astronomy ...
Astronomy
Feb 10, 2026
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Using the James Webb Space Telescope (JWST), an international team of astronomers has discovered a new massive and quiescent red galaxy, which they dubbed "Red Potato." The discovery was reported in a research paper published ...
This NASA/ESA Hubble Space Telescope image features an uncommon galaxy with a striking appearance. NGC 7722 is a lenticular galaxy located about 187 million light-years away in the constellation Pegasus.
Astronomy
Feb 2, 2026
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The mystery of dark matter—unseen, pervasive, and essential in standard cosmology—has loomed over physics for decades. In new research, I explore a different possibility: Rather than postulating new particles, I propose that ...
Last year, astronomers were fascinated by a runaway asteroid passing through our solar system from somewhere far beyond. It was moving at around 68 kilometers per second, just over double Earth's speed around the sun.
Astronomy
Jan 28, 2026
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The NASA/ESA/CSA James Webb Space Telescope has topped itself once again, delivering on its promise to push the boundaries of the observable universe closer to cosmic dawn with the confirmation of a bright galaxy that existed ...
Astronomy
Jan 28, 2026
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