How Binary Star Systems May Launch Rogue Jupiters
Aleksandra Ćalović and collaborators show that Jupiter-like free-floating planets may be ejected from young binary systems formed by disc fragmentation. Their 3D simulations reveal that as a secondary star grows, its gravitational interactions with nearby planets often fling them into interstellar space. These ejections are most common in massive binaries and could explain the abundance of rogue Jupiters observed in young star clusters.
Binary Stars Illuminate the Secrets of NGC 2506: A Precise Age and Distance for a Middle-Aged Star Cluster
Kadri Yakut et al. used data from Gaia, TESS, and ground-based telescopes to analyze five binary stars in the open cluster NGC 2506. By jointly modeling their light, velocity, and energy distributions, the team derived a precise cluster age of 1.94 billion years and a distance of about 3,200 parsecs. This method demonstrates how binary systems can accurately reveal a cluster’s age, distance, and evolutionary state.
How Binary Stars Complicate the Dark Matter Mystery in Tiny Galaxies
Gration and collaborators show that binary stars can skew measurements of ultrafaint dwarf galaxies by inflating their stellar velocity dispersions. Using simulations, they find unresolved binaries add significant “noise,” sometimes making globular clusters appear like galaxies. The effect is even stronger if the galaxies form fewer low-mass stars. Their work highlights the need to account for binaries when estimating galactic masses and testing dark matter theories.
When Discs Dance: How Misaligned Binary Stars Create Unusual Spiral Arms
Rowther et al. use 3D simulations to show that moderately misaligned circumbinary discs can form unusual leading spiral arms at connection points between inner and outer discs. These spirals don’t rotate with the disc and vanish when the discs align or fully break. The effect is independent of detailed disc physics, and in some cases shadows can also launch trailing spirals, meaning both types can coexist.
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.