September 2026 · 7 Articles · Pages 1–147
September 2026
Open Access7 Articles · Pages 1–147
We compile a comprehensive catalog of 1,247 coronal mass ejections detected by the SOHO/LASCO and STEREO coronagraphs during the ascending and maximum phases of Solar Cycle 25 (2020–2026). By correlating CME properties with in situ solar wind measurements at L1, we characterize the dependence of geoeffectiveness on CME speed, angular width, and source region latitude. Our analysis reveals that Cycle 25 has produced 30% more fast halo CMEs than the equivalent phase of Cycle 24, with implications for space weather forecasting and the protection of orbital infrastructure.
We present multi-band optical monitoring of 92 T Tauri stars in the Chamaeleon I molecular cloud spanning three consecutive observing seasons. Time-series analysis reveals periodic variability consistent with starspot modulation in 64 sources, irregular accretion-driven fluctuations in 21, and UX Orionis-type extinction events attributed to circumstellar disk material in 7. We derive rotation periods for the spotted sample and find a statistically significant disk-locking signature, with disk-bearing stars rotating more slowly than their diskless counterparts at the 3-sigma level.
Using spectroscopic redshifts of 4.2 million luminous red galaxies from the DESI Year-2 data release, we reconstruct the three-dimensional cosmic web over the redshift range 0.4 < z < 1.1. We apply the DisPerSE filament-finding algorithm to identify cosmic filaments and voids, and measure galaxy properties as a function of distance to the nearest filament spine. Galaxies within 2 Mpc of filaments show systematically redder colors and lower specific star formation rates, confirming predictions from hydrodynamical simulations regarding the role of the cosmic web in quenching galaxy evolution.
We analyze the scattering and scintillation properties of 112 fast radio bursts detected by CHIME/FRB and the Australian SKA Pathfinder to constrain the turbulence spectrum of the intergalactic medium. By comparing observed temporal broadening and spectral modulation indices with propagation models, we find that the IGM turbulence is consistent with a Kolmogorov spectrum on scales of 0.01–100 AU. The inferred scattering measures place new constraints on the amplitude of density fluctuations in the diffuse ionized intergalactic gas, complementing dispersion measure studies of the cosmic baryon budget.
We report the discovery of a narrow stellar stream extending over 45 degrees on the sky in the outer halo of the Milky Way, identified using proper motions and photometry from Gaia Data Release 4. Follow-up spectroscopy of 28 member stars reveals a mean metallicity of [Fe/H] = −2.3 with a small intrinsic dispersion, consistent with a disrupted globular cluster progenitor. Orbit integration in a realistic Galactic potential constrains the stream’s pericentric and apocentric distances to 18 and 95 kpc, respectively, providing a new tracer of the Milky Way mass distribution at large galactocentric radii.
The application of machine learning to exoplanet transit detection has grown rapidly with the availability of large photometric datasets from Kepler, K2, and TESS. This review provides a comprehensive survey of supervised and unsupervised approaches, including convolutional neural networks, random forests, and autoencoders, applied to light curve classification and planet candidate identification. We present standardized benchmark comparisons on common datasets, analyze failure modes and systematic biases inherent to each method, and identify promising directions including self-supervised pre-training on unlabeled light curves and physics-informed neural network architectures.
We present JWST/MIRI medium-resolution spectroscopy of Saturn spanning 5–28 micrometers, revealing phosphine absorption bands at unprecedented spectral resolution and signal-to-noise ratio. Retrieval analysis indicates a phosphine mixing ratio that decreases sharply above the 500 mbar pressure level, inconsistent with simple thermochemical equilibrium profiles. We propose that photochemical destruction in the upper troposphere combined with dynamical quenching from deeper atmospheric layers best explains the observed vertical distribution, with implications for understanding phosphorus chemistry in giant planet atmospheres more broadly.