Physics and Astronomy · Astronomy and Astrophysics
A joint analysis of the neutron-star merger GW170817 and the gamma-ray burst GRB 170817A found no evidence that the gravitational constant has changed over time. The study limits its fractional rate of change to between −3.36 × 10⁻⁹ and 5.34 × 10⁻¹⁰ per year.
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 review examines how pulsating stars in eclipsing binary systems can be used to study stellar interiors and the effects of tides. Space-based observations, combined with repeated measurements of starlight spectra, can provide model-independent masses and radii for thousands of systems.
