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.
A new study published in Nature Astronomy indicates that the dense, star- and dark-matter–rich environments around supermassive black hole binaries pack on the order of a million solar masses into each cubic parsec. The team ...
For this month's ESA/Hubble Picture of the Month, NASA/ESA's Hubble Space Telescope is joined by ESA's Euclid to create a new view of the most visually intricate remnants of a dying star: the Cat's Eye Nebula, also known ...
Astronomy
Mar 3, 2026
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It is one of the most famous questions in science, and it was asked, as legend has it, over lunch. Enrico Fermi, the physicist who helped build the first nuclear reactor and whose name graces a unit of length so small it ...
Astrobiology
Mar 2, 2026
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NGC 941 is located approximately 55 million light-years away in the constellation Cetus. This faint galaxy is classified as an intermediate spiral, exhibiting characteristics between a barred spiral with a central bar and ...
Astronomy
Feb 26, 2026
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An international team of astronomers has employed the Atacama Large Millimeter/submillimeter Array (ALMA) to investigate molecular gas in a nearby galaxy known as NGC 1387. Results of the observational campaign, published ...
We have known for several decades that the universe is expanding. Scientists use multiple techniques to measure the present-day expansion rate of the universe, known as the Hubble constant. These methods are internally consistent ...
Astronomy
Feb 24, 2026
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An international team of scientists led by the Institute of Cosmos Sciences at the University of Barcelona (ICCUB) and the Institute of Space Studies of Catalonia (IEEC) has presented REGALADE, an unprecedented catalog covering ...
Astronomy
Feb 20, 2026
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That the universe is expanding has been known for almost a hundred years now, but how fast? The exact rate of that expansion remains hotly debated, even challenging the standard model of cosmology. A research team at the ...
Astronomy
Feb 19, 2026
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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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