地球与行星天体物理

We present an investigation into the fate of disrupting near-Sun comet C/2019 Y4 (ATLAS). Imaging observations with the Lowell Discovery Telescope (LDT), obtained 3--5 months after the reported disruption and the last sighting, constrained…

The high-precision photometry from NASA's Kepler and TESS missions has revolutionized exoplanet detection, enabling the discovery of over 5500 confirmed exoplanets via the transit method and around 10000 additional candidates awaiting…

The search for potentially habitable exoplanets is a primary objective in modern astrophysics, yet the vast number of candidates discovered by missions like Kepler and TESS presents a significant challenge for detailed follow-up…

Planetary materials show systematic variations in their nucleosynthetic isotope compositions that resonate with orbital distance. The origin of this pattern remains debated, limiting how these isotopic signatures can be used to trace the…

Despite the fact that the terrestrial planets formed from the protoplanetary disk, their compositions show marked departures from that of solar nebula condensates. Metallic cores fix oxygen fugacities ($f$O$_2$s) of the planets to 5…

Type II orbital migration is a key process to regulate the mass and semimajor axis distribution of exoplanetary giant planets. The conventional formula of type II migration generally predicts too rapid inward migration to reconcile with the…

3I/ATLAS, also known as C2025 N1 (ATLAS), is the third known macroscopic interstellar object to pass through our Solar System. We report serendipitous Transiting Exoplanet Survey Satellite (TESS) observations of 3I/ATLAS taken between…

We report the detection and characterization of TOI-201 c, a long-period transiting companion to the warm Jupiter TOI-201 b. Its presence was first inferred from high-amplitude transit timing variations (TTVs) in TOI-201 b, pointing to a…

Computed using the APPLE planetary evolution code, we present updated evolutionary models for Jupiter and Saturn that incorporate helium rain, non-adiabatic thermal structures, and "fuzzy" extended heavy-element cores. Building on our…

Rocky planets orbiting M-dwarf stars are prime targets for atmospheric characterization, yet their long-term evolution under intense stellar winds and high-energy radiation remains poorly constrained. The Kepler-1649 system, hosting two…

A goal of the future Habitable Worlds Observatory (HWO) is to directly image and spectroscopically characterize true Earth-analogs. However, if a large fraction of HWO target stars host unknown dynamically disruptive giant planets in their…

We consider sampling and detection strategies for solar illuminated space debris. We argue that the lowest detectable debris cross section may be reduced by 10-100x by analysis of stacks of image frames collected at high rates rather than…

Large-amplitude variations are commonly observed in the atmospheres of directly imaged exoplanets and brown dwarfs. VHS 1256B, the most variable known planet-mass object, exhibits a near-infrared flux change of nearly 40%, with red color…

High-resolution, near-infrared observations have revealed prominent, two-armed spirals in a multitude of systems, such as MWC~758, SAO~206462, and V1247~Ori. Alongside the classical theory of disk-companion interaction, shadow-based driving…

Context. Neptune-sized exoplanets or exo-Neptunes are fundamental in the description of exoplanet diversity. Their evolution is sculpted by atmospheric escape, often traced by absorption in the H i Lyman-{\alpha} line at 1,216 {\AA} and the…

Through detailed modeling of all three stars, we show that HIP-44302 is a false positive triple-star system. While the Transiting Exoplanet Survey Satellite initially designated the object as a planetary candidate, observing a 10-day…

Modeling the atmospheres of exoplanets is fundamental to understanding their atmospheric physics and chemical processes. While one-dimensional (1D) atmospheric models with 1D radiative transfer (RT) have been widely used, advances in…

We present observations of two binary systems within the cold classical region of the Kuiper belt$-$2001 XR254 and 2016 BP81$-$obtained with the JWST Near-Infrared Spectrograph. The measured reflectance spectrum of 2001 XR254 is…

We present new transit timing measurements for the white dwarf-cold Jupiter system WD 1856+534, extending the baseline of observations from 311 epochs to 1498 epochs. The planet is unlikely to have survived the host star's red-giant phase…

Migration typically occurs during the formation of planets and is closely linked to the planetary formation process. In classical theories of non-accreting planetary migration, both type I and type II migration typically result in inward…