2+ hour 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…...

2+ hour, 45+ 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…...

3+ hour, 30+ min ago   (663+ words) The cosmic microwave background is the oldest light we can observe. Here is where it came from, what its tiny patterns reveal, and why it still matters. About 380,000 years after the Big Bang, the expanding universe had cooled enough for…...

5+ hour 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…...

2+ day, 21+ hour ago   (1203+ words) Twenty-seven faint objects beyond Neptune are giving astronomers a rare look at the planet-building material that survived when the outer solar system stopped growing. The outer solar system is not empty. Beyond Neptune, in the cold region known as the…...

2+ day, 22+ 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, 23+ hour ago   (556+ words) A brilliant X-ray source is not automatically a black hole. Matter falling toward a neutron star can also become intensely luminous, and some neutron stars have surprised astronomers by producing far more radiation than expected. Identifying the object requires evidence…...

4+ day, 2+ hour ago   (493+ words) Twenty-seven faint objects beyond Neptune have emerged from a deep James Webb Space Telescope survey, extending the search for the solar system’s building blocks to worlds only kilometres across. Hubble observations of part of the sample add a second clue:…...

6+ day, 4+ 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, 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…...