Stars

Astronomers have identified the source of unusual X-rays from the bright star gamma-Cas as a hidden white dwarf companion siphoning material from it. High-resolution data from the XRISM space mission confirmed that the emissions arise from matter heating up as it falls onto the unseen star. The discovery ends a puzzle that has intrigued scientists since the 1970s.

4. april 2026 Rapporteret af AI

Astronomers have discovered that aging stars expanding into red giants are engulfing close-orbiting giant planets. A study of nearly half a million stars shows fewer such planets around more evolved red giants, suggesting many have been destroyed. The findings come from data collected by NASA's Transiting Exoplanet Survey Satellite.

Observations of the red giant star R Doradus reveal that starlight alone cannot drive its powerful stellar winds, contradicting a longstanding astronomical model. Researchers at Chalmers University of Technology in Sweden used advanced telescopes to show that surrounding dust grains are too small to be propelled by light pressure. This discovery prompts new ideas about how essential elements for life are distributed across the galaxy.

26. december 2025 Rapporteret af AI

Astronomers have analyzed vibrations in a red giant star near a dormant black hole, uncovering evidence of a past stellar merger that defies expectations. The star, part of the Gaia BH2 system, appears ancient in chemistry but young in structure, spinning unusually fast. This discovery challenges models of stellar evolution in quiet black hole binaries.

Astronomers have revealed that the famous Pleiades star cluster, known as the 'Seven Sisters,' is merely the core of a much larger stellar complex containing thousands of related stars. Using data from NASA's TESS and ESA's Gaia telescopes, researchers at the University of North Carolina at Chapel Hill expanded the cluster's known size by a factor of 20. This finding offers new insights into star formation and the Milky Way's structure.

14. november 2025 Rapporteret af AI

An isolated galaxy in the Local Void, NGC 6789, continues to form new stars despite lacking apparent gas fuel. New deeper images reveal no signs of mergers or gas inflows that could explain the phenomenon. The mystery of its star formation deepens, challenging astronomers' understanding of galactic evolution.