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 using the James Webb Space Telescope (JWST) have discovered a stellar bar in GN20, a massive galaxy seen just 1.5 billion years after the Big Bang. The new paper was submitted to the preprint server arXiv on May ...
Which comes first, the galaxy or the black hole? We don't know, but scientists have long thought it could be the galaxy: Large stars within an existing galaxy consume their fuel and collapse to form black holes, which can ...
Astronomy
May 29, 2026
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Astronomers may have uncovered a hidden supermassive black hole inside the famous Antennae galaxies NGC 4038/4039, a pair of colliding galaxies best known for their spectacular bursts of star formation. The paper outlining ...
NASA's Nancy Grace Roman Space Telescope is poised to make a major leap in the hunt for worlds outside our solar system, known as exoplanets. Scientists expect the mission to reveal around 100,000 worlds—a staggering leap ...
Astronomy
May 28, 2026
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On the night of 18 December 2019, a star in our satellite galaxy, the Large Magellanic Cloud, briefly got brighter. Not dramatically nor explosively, just a smooth symmetrical rise and fall in brightness lasting about an ...
Astronomy
May 28, 2026
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This NASA Hubble Space Telescope image features the dwarf irregular galaxy ESO 490-017, roughly 12,000 light-years in diameter and some 23 million light-years away in the constellation Canis Major. The galaxy's low surface ...
Astronomy
May 27, 2026
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A large protocluster of galaxies that existed 12.6 billion years ago, first discovered with the Subaru Telescope, has been examined in detail using the James Webb Space Telescope (JWST). The study found that galaxies in crowded ...
Astronomy
May 26, 2026
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New observations from the James Webb Space Telescope have revealed fresh details about one of the most luminous known objects in the universe: the dust-shrouded quasar W2246−0526, seen just 1.2 billion years after the Big ...
At the center of most large galaxies sits a supermassive black hole (SMBH). When these black holes are actively consuming material, they become incredibly luminous quasars. But some quasars appear wrapped in thick clouds ...
Researchers at The University of Alabama in Huntsville (UAH), a part of The University of Alabama System, have identified a promising new method for measuring the mass of galaxies orbiting the Milky Way by using pulsars, ...
Astronomy
May 22, 2026
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