6+ hour, 7+ min ago   (282+ words) Dark photons are one proposed explanation for dark matter. A new calculation suggests that the early universe’s plasma may have stopped them from depositing heat as efficiently as earlier models predicted. The post Early-Universe Plasma May Have Kept Dark Photons…...

6+ hour, 52+ min ago   (603+ words) The enormous Cygnus Bubble is usually linked to a busy star-forming region. A new study argues that the microquasar Cygnus X-3 may be the more natural source of its highest-energy gamma rays. Cygnus X-3 is a microquasar, a binary system containing a…...

9+ hour, 7+ min ago   (476+ words) A sub-threshold Einstein Probe X-ray flash was found after ZTF spotted supernova SN 2025wkm. Researchers link the signal to shock breakout and a possible magnetar-powered engine. EP250827b was a soft X-ray flash that lasted more than 1,000 seconds. Spectral fits put its peak…...

3+ day, 2+ hour ago   (1153+ words) The objects are unusually soft in X-rays but bright in extreme ultraviolet light—exactly the combination that makes them difficult to find and potentially important to the history of stars and galaxies. A galaxy can be full of powerful objects…...

3+ day, 4+ hour ago   (636+ words) Look into the middle of N44 and the most striking feature is what seems to be missing. A vast opening interrupts the glowing gas, while stars crowd the surrounding scene. What could carve a cavity this large—and what happens to…...

6+ day, 8+ hour ago   (624+ words) A neutron star is what remains after the core of a massive star collapses. It is not a small ordinary star. It is the crushed core of a dead one, compressed until protons and electrons are forced together and most…...

1+ week, 2+ day ago   (752+ words) A parsec is a distance defined by parallax. Here is how astronomers use the unit to measure the space between stars and galaxies. What is a parsec? It is a unit of distance used by astronomers to describe the space…...

1+ week, 4+ day ago   (373+ words) Researchers have completed one of the largest computer simulations of cosmic history yet assembled. Called ASTRID, it follows the growth of galaxies and black holes from the universe’s early days to the present, giving astronomers a virtual laboratory for testing…...

1+ week, 5+ day ago   (453+ words) Astronomers often treat the thin streams of stars around the Milky Way as sensitive tracers of dark matter. A new University of Washington simulation shows why that evidence needs to be read carefully: the visible structure of a galaxy can…...

2+ week, 8+ hour ago   (754+ words) The explosion is not simply a large firework at the surface. In a massive star, the core has been building heavier elements through nuclear fusion. When the core reaches iron, fusion can no longer provide the energy needed to support…...