5 papers
Scientific Validation of the SPARC4 Pipeline: Multi-band Imaging, Polarimetry, and Photometric Time Series for Improved Characterization of Transiting Exoplanets
Eder Martioli, Claudia V. Rodrigues, Julio C. N. Campagnolo +14
High-cadence multi-band imaging and polarimetry have important scientific applications in astronomy. Observations of transits of exoplanets are a particular application that requir…
Two Low Mass-Ratio Microlensing Planets and Two Types of Central-Resonant Degeneracy
Yuchen Tang, Weicheng Zang, Yoon-Hyun Ryu +39
We present observations and analysis of two low planet/host mass-ratio () microlensing planets discovered in high-magnification events. KMT-2025-BLG-0811Lb has $q \sim 4.5 \time…
Starspot temperature of CoRoT-2 from multiwavelength observations with SPARC4
Adriana Valio, Eder Martioli, Andre O. Kovacs +5
Measuring starspot temperatures is crucial for understanding stellar magnetic activity, as it affects stellar brightness variations, influences exoplanet transit measurements, and…
A Comprehensive Analysis of Three Microlensing Planet Candidates with the Planet/Binary Degeneracy
Jiyuan Zhang, Weicheng Zang, Yoon-Hyun Ryu +65
We present observations and analyses of three high-magnification microlensing events: KMT-2022-BLG-0954, KMT-2024-BLG-0697, and MOA-2024-BLG-018. All three exhibit the "Planet/Bina…
HIP 8522: A Puzzling Young Solar Twin with the Lowest Detected Lithium
Jhon Yana Galarza, Diego Lorenzo-Oliveira, Thiago Ferreira +8
We present HIP 8522, a young solar twin with the lowest detected lithium, potentially a field blue straggler or the result of episodic early accretion. Its stellar parameters ($T_{…