Physics and Astronomy · Astronomy and Astrophysics
Astronomers report a possible second-generation planet orbiting the white dwarf HS 0209+0832. Its unusual chemical signature and a repeating 4.399-day brightness signal are consistent with an evaporating gas giant formed from material expelled by the star.
A study in The Astrophysical Journal examines how black holes in isolated pairs could acquire spins that are tilted relative to their orbit or point in the opposite direction. The results suggest these features are not necessarily evidence that a pair formed through close encounters in a dense stellar environment.
Astronomers have studied a rapidly spinning neutron star in a roughly one-day orbit with a likely helium white dwarf. Its unusually changing orbit and signs of magnetized material between the stars suggest it may represent a transitional stage between two types of binary systems.
Researchers developed an AI-based method for reconstructing changing radio images of black-hole jets as continuous videos. Applied to repeated observations of the blazar 3C 345, it estimated the local, instantaneous motion of plasma rather than tracking only separate jet features.
A new framework suggests that the supermassive black holes seen less than 700 million years after the Big Bang may have begun as unusually large seeds. It makes testable predictions for observations with the James Webb Space Telescope and future gravitational-wave detectors.
