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 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.
Finding oxygen or methane in a rocky exoplanet’s atmosphere would not by itself show that life is present. A study in Astrobiology finds that a proposed space telescope would need to examine light from near-ultraviolet through near-infrared wavelengths to assess habitability and investigate nonbiological explanations.
Globular clusters around the Milky Way reveal evidence of a previously identified but debated merger that occurred about 1.8 billion years before the Gaia-Sausage-Enceladus merger. The incoming system had a similar stellar mass and deposited most of it in the Milky Way’s inner 6 kiloparsecs.
