An analysis of 11 extremely low mass ratio contact binaries found that two systems changed their out-of-eclipse brightness asymmetry within one TESS sector. It also found mixed orbital-period changes and evolutionary tracks that could not reproduce the shortest-period targets under the tested assumptions.
A seven-star comparison found a sharp contrast between two ways of selecting slowly rotating, chemically peculiar A-type stars for magnetic-field searches.
The model recovered 70% of labeled likely young stars and added 14,426 candidates, but recall ranged from almost 100% in M dwarfs to about 0% in O-type stars.
An analysis of 225 Rowan et al. (2023) candidates with two eclipsing periods reports 76 confirmed blends and a 33.8% false-positive fraction for the examined set.
A short VLA observing run on the single star AU Mic found strong variability even during selected quiet intervals, along with two clear flares. The authors interpret the pattern as evidence that many small, unresolved flares may help sustain the star’s radio emission, but the result is based on one star at one epoch.
A targeted optical search of nine unusual eclipsing candidates reported at least four magnetic white dwarfs, including three likely wind-accreting pre-polars and one normal polar, while other classifications remained unclear.
The preprint reports that LY UMa was bluer during the brighter of two B and V observing runs and estimates a K7-K8V mass donor using distance and assumed light-share calculations. It also gives a single V-band estimate for nearby Mrk 153.
A computational study followed wide stellar triples from stellar birth to black-hole-binary merger, finding rare stable and unstable routes and distinct orbital and spin signatures.
A multi-wavelength case study of NOAA active region 12297 records recurrent brightenings along a fishbone-like solar magnetic structure and interprets their motion as sequential reconnection, while acknowledging that direct node-to-node triggering was not observed.
A new computational study finds that circumbinary-disc interaction can match the observed eccentricities of stripped giant binaries only under demanding assumptions, while failing to explain most short post-AGB periods.
A narrative review of selected studies finds machine-learning methods are helping search survey data for hot subdwarfs and white dwarfs, while reported classifications and population estimates still require physical confirmation.
High-resolution infrared spectra suggest TRAPPIST-1 has broadly solar-like chemistry, while its carbon isotope ratio is higher than the solar-system value.
Researchers found a linked set of thermal, motion and magnetic-topology signatures in a selected solar brightening. The authors describe the pattern as consistent with reconnection involving a twisted magnetic structure, but not as proof that reconnection occurred.
A modeling study tests whether machine learning can estimate how strong an ongoing solar flare will become, finding larger errors and lower uncertainty coverage for stronger events.