Search Publications
Ensemble Learning for Stellar Classification and Radius Estimation from Multimodal Data
Luo, A. -Li; Kong, Xiao; Li, Xiang-Ru +2 more
Stellar classification and radius estimation are crucial for understanding the structure of the Universe and stellar evolution. With the advent of the era of astronomical big data, multimodal data are available and theoretically effective for stellar classification and radius estimation. A problem is how to improve the performance of this task by …
VLBI with SKA: Possible Arrays and Astrometric Science
Xu, Ye; Liu, Dejian; Hao, Chaojie +4 more
The next generation of very long baseline interferometry (VLBI) is stepping into the era of microarcsecond (µas) astronomy, and pushing astronomy, especially astrometry, to new heights. VLBI with the Square Kilometre Array (SKA), SKA-VLBI, will increase current sensitivity by an order of magnitude, and reach astrometric precision routinely b…
V0405 Dra: A New Deep and Low Mass Ratio Contact Binary with Extremely Fast Decrease in the Orbital Period
Zheng, Jie; Jiang, Lin-Qiao; Tian, Xiao-Man +5 more
V0405 Dra is a W UMa-type binary star. Based on the TESS data, we have conducted an orbital period study and performed a light curve analysis for the system. The orbital period study reveals that the O ‑ C curve for V0405 Dra exhibits secular decrease at an extremely high rate of dP/dt = ‑2.71 × 10‑6 day year‑1, along with pe…
Long-term Speckle Interferometric Monitoring of Binary Systems: 2007–2023 Positional Measurements and Orbits of Seven Objects
Mitrofanova, Arina; Dyachenko, Vladimir; Beskakotov, Anatoly +3 more
The results of seventeen years of speckle interferometric monitoring of seven objects (Chara 122Aa, GJ 3010, HIP 1987, GJ 3076, HIP 11253, HIP 11352, and HIP 14929) are presented. Observational data were obtained at the 6 m Big Telescope Alt-azimuthal Special Astrophysical Observatory of the Russian Academy of Science (BTA SAO RAS) from 2007 to th…
Photometric Analysis for Asteroid (81) Terpsichore using Convex Inversion and Phase Function Fitting Methods
Gao, Quangui; Li, Huaizhen; Qin, Longhua +5 more
The shapes and rotation states (periods and pole orientations) of main-belt asteroids are important for understanding their formation and evolution. In order to obtain sufficient photometric data covering different apparitions for asteroid (81) Terpsichore, ground-based photometric observations in 2020 and 2021 were carried out. By combining publi…
A Geometric Distortion Solution Specifically for Historical Observations and its Implementation
Lin, F. R.; Peng, Q. Y.; Zheng, Z. J. +1 more
Geometric distortion (GD) critically constrains the precision of astrometry. Using well-established methods to correct GD requires calibration observations, which can only be obtained using a special dithering strategy during the observation period. Unfortunately, this special observation mode is not often used, especially for historical observati…
Resolution Enhancement of SOHO/MDI Magnetograms
Qin, Ying; Yu, Xiao-Guang; Ji, Kai-Fan +1 more
Research on the solar magnetic field and its effects on solar dynamo mechanisms and space weather events has benefited from the continual improvements in instrument resolution and measurement frequency. The augmentation and assimilation of historical observational data timelines also play a significant role in understanding the patterns of solar m…
Revisiting the Velocity Dispersion–Size Relation in Molecular Cloud Structures
Chen, Zhiwei; Zhang, Shiyu; Su, Yang +10 more
Structures in molecular ISM are observed to follow a power-law relation between the velocity dispersion and spatial size, known as Larson's first relation, which is often attributed to the turbulent nature of molecular ISM and imprints the dynamics of molecular cloud structures. Using the 13CO (J = 1–0) data from the Milky Way Imaging S…
FAST Observations of Four Comets to Search for the Molecular Line Emissions between 1.0 and 1.5 GHz Frequencies
Tsai, Chao-Wei; Duan, Yan; Li, Di +11 more
We used the Five-hundred-meter Aperture Spherical radio Telescope (FAST) to search for the molecular emissions in the L-band between 1.0 and 1.5 GHz toward four comets, C/2020 F3 (NEOWISE), C/2020 R4 (ATLAS), C/2021 A1 (Leonard), and 67P/Churyumov-Gerasimenko during or after their perihelion passages. Thousands of molecular transition lines fall i…
A Special Kind of Interplanetary Coronal Mass Ejection
Zhao, G. Q.; Zhao, Y.; Li, H. B. +3 more
It is generally believed that coronal mass ejections (CMEs) have magnetic flux rope structures because of their helical shapes. However, only about 30%–40% of interplanetary CMEs (ICMEs) have a local magnetic flux rope structure. The usual explanations are that the spacecraft only crossed the flank of the ropes and failed to detect the complete ma…