Spinning Spots: Tracking the Rotation of Solar α-Sunspots and What It Means for Other Stars
Emily Joe Lößnitz and colleagues measured how α-sunspots, stable round sunspots, rotate across the Sun. They found these spots spin slightly faster than the quiet Sun but slower than average sunspots, indicating shallower anchoring. Using this data, they developed a rotation law adaptable to other stars, showing how differential rotation shapes stellar light curves and can influence exoplanet studies.
XX Tri: Watching the Sky’s Most Spotted Star Evolve Over 40 Years
This study tracks 40 years of brightness changes in XX Tri, a highly active red giant star covered in dark starspots. Researchers identified multiple magnetic cycles, surface temperature increases, and solar-like differential rotation. Their findings suggest that the star’s unspotted brightness has increased over time, challenging assumptions in spot modeling and offering insights into stellar magnetism in binary systems.
Peering into the Starspots: The First Doppler Image of λ Andromedae
Researchers produced the first Doppler image of λ Andromedae, revealing four large starspots and refining its orbital parameters with high precision. By correcting radial velocity signals caused by these spots, they confirmed the star’s nearly circular orbit and identified its companion as a likely brown dwarf. This study improves our understanding of magnetic activity in evolved stars and its impact on orbital measurements.
Starspot Activity and Rotation of SZ Piscium: A Doppler Imaging Study
This study examines the magnetic activity and rotation of SZ Piscium, a binary star system, using Doppler imaging to map starspots on the surface of its K-type subgiant star. The researchers observed widespread starspots, including a stable polar spot, and measured the star's differential rotation, finding that its equator rotates faster than its poles. They also confirmed the presence of a third companion star in the system, orbiting with a period of 1530 days.