Unveiling a Pulsating Pair: A Close Binary with a Pre-White Dwarf in WASP 1021-28
Lee et al. (2025) analyze the binary system WASP 1021-28, made up of an A-type star and a pre-He white dwarf. Using TESS and VLT data, they model the system’s physical properties and detect pulsations from both stars. Their results reveal insights into stellar evolution, binary interaction, and the role of a distant third star in shaping the system’s history.
Unraveling the Binarity of B-type Supergiants in the Small Magellanic Cloud
A new study by Britavskiy et al. examines the binary nature of early B-type supergiants (BSGs) in the Small Magellanic Cloud using data from the Binarity at LOw Metallicity (BLOeM) survey. Analyzing 262 stars, the team found that about 40% are likely binaries, with a sharp drop in binarity for stars cooler than 18,000 K. The findings suggest that mergers play a key role in BSG evolution, and that binary fractions remain consistent across different metallicity environments. Future observations will further clarify how these massive stars evolve.
The Mystery of Wide Binaries in Metal-Poor Stars
This study examines the frequency of wide binary companions among metal-poor stars using Gaia and infrared surveys. Researchers found that while close binaries (separations <8 AU) are common (about 20%), wide binaries (separations >8 AU) are rare, with a frequency below 3%. This suggests that metal-poor environments and dynamical interactions disrupt wide binaries over time. The findings provide insights into star formation in the early universe.
Uncovering the Mystery of Stripped Stars in Binary Systems
Stripped stars in binary systems lose their hydrogen-rich layers, contributing to supernovae and ionizing radiation. This study shows that while low-mass stripped stars are common, massive stripped stars are rare in low-metallicity environments, forming a "helium-star desert." These findings impact our understanding of early galaxies, cosmic reionization, and stellar evolution, highlighting the need for further observations.