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Supergiant
Supergiants are the most massive stars. Supergiants can have masses from 10 to 70 solar masses and brightness from 30,000 up to hundreds of thousands times the solar luminosity. They vary greatly in radii, usually from 30 to 500, or even in excess of 1000 solar radii. Because of their extreme masses they have short lifespans of only 10 to 50 million years and are only observed in young cosmic structures such as open clusters, the arms of spiral galaxies, and in irregular galaxies. They are less abundant in spiral galaxy bulges, and are not observed in elliptical galaxies, or globular clusters, all of which are believed to be composed of old stars. Currently, the largest known stars in terms of physical size, not mass or luminosity, are the supergiants VV Cephei, V354 Cephei, KW Sagitarii, KY Cygni, and the Garnet Star.
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Space & Time News
August 7, 2026
Aug. 7, 2026 A ten-month Antarctic experiment found that astronauts may struggle not only with loneliness but also with spending too much time around the same people. Frequent contact was linked to greater ...
Aug. 7, 2026 Metal-rich asteroids could one day become hardware stores for Mars, supplying the materials needed to build and repair a growing colony. A new analysis shows that carefully selected asteroids may be reachable with current spacecraft technology. Some ...
July 31, 2026 Scientists have built the first all-optical photonic time crystal, allowing them to reshape the behavior of terahertz light at extraordinary speeds. The breakthrough could open the door to ultrafast computing, smarter communication systems, advanced ...
July 30, 2026 Astronomers may have been listening for alien civilizations in only a small slice of the radio spectrum while overlooking a largely unexplored range of higher frequencies. Using archived data from the ALMA telescope in Chile, researchers conducted ...
July 28, 2026 NASA’s Psyche spacecraft aced its Mars flyby, using the planet’s gravity to speed toward its 2029 encounter with a metal-rich asteroid. The spacecraft tested its cameras, magnetometer, and ...
July 23, 2026 NASA is preparing for future astronaut landings on the Moon with an unusually ambitious orbital rehearsal. During Artemis III in 2027, Orion astronauts will rendezvous and dock separately with ...
July 21, 2026 China’s Chang’e-6 samples have uncovered a surprising difference between the Moon’s two hemispheres. Solar wind particles penetrated deeper into the far-side soil because Earth’s ...
July 19, 2026 The asteroid that wiped out the dinosaurs was likely an exceptionally rare CO chondrite from a distant region of the solar system. Its unusual chemistry suggests that planet-cooling dust and debris, ...
July 18, 2026 A catastrophic asteroid breakup may have triggered a huge wave of impacts across the inner solar system about 800 million years ago. The debris was launched from near a gravitational gateway controlled by Jupiter, sending fragments toward Earth, the ...
July 17, 2026 Scientists say new technologies have reopened the debate over whether Mars could someday be terraformed, turning a once impossible idea into a serious research topic. Before anyone tries to reshape the Red Planet, though, researchers say we must ...
July 15, 2026 NASA's PACE satellite captured the Black Sea glowing turquoise during its annual phytoplankton bloom. The vivid color comes from massive numbers of coccolithophores, microscopic organisms whose reflective shells brighten the water enough to be seen ...
July 15, 2026 NASA has chosen 41 commercial technology projects that could solve critical challenges for future missions to the Moon and Mars. From powering lunar outposts to protecting spacecraft from Moon dust, the innovations are designed to push both space ...
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Aug. 6, 2026 A supermassive black hole has been found lurking about 30,000 light-years from the center of its galaxy—the first dormant black hole detected so far from a galactic core. It revealed itself only ...
Aug. 5, 2026 August brings four major celestial events, including a solar eclipse and the peak of the Perseid meteor shower. Dark New Moon skies could make the Perseids especially impressive, while Venus will ...
Aug. 4, 2026 Photons traveling through a cloud of atoms can emerge so early that they appear to have spent a negative amount of time inside. Researchers tested ...
Aug. 3, 2026 Hidden moon ice may reveal itself through the way it bends and reflects vibrations from moonquakes. The technique could help astronauts locate vital water supplies and uncover clues about the origins ...
Aug. 3, 2026 The solar wind may be stripping away Mars’ atmosphere by creating giant rolling waves along its outer edge. Data from MAVEN and Tianwen-1 show that these waves form plasma clouds that carry ...
Aug. 2, 2026 Dark matter particles may exert a hidden force on one another, but its effects are stranger than expected. An extra attraction helps the particles cluster, yet it also makes dark matter effectively ...
Aug. 1, 2026 Scientists have identified LHAASO J1912+1014u as a cosmic accelerator that can push protons beyond one quadrillion electron volts. The finding may ...
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Aug. 1, 2026 Primordial black holes may occasionally pass through white dwarf stars and trigger enormous Type Ia supernova explosions. Researchers found that these events could explain chemical patterns seen in ...
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