Search Publications
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…
13 Galactic Star Clusters in Gaia DR3 Identified by An Improved FoF and UPMASK Hybrid Method Using MvC
Mei, Ying; Wang, Feng; Li, Zhongmu +2 more
Open clusters (OCs) serve as invaluable tracers for investigating the properties and evolution of stars and galaxies. Despite recent advancements in machine learning clustering algorithms, accurately discerning such clusters remains challenging. We re-visited the 3013 samples generated with a hybrid clustering algorithm of FoF and pyUPMASK. A mult…
Study of 26 Galactic Open Clusters with Extended Main-sequence Turnoffs
Li, Zhong-Mu; Deng, Yang-Yang
Recent studies indicate that some Galactic open clusters (OCs) exhibit extended main-sequence turnoff (eMSTO) in their color–magnitude diagrams (CMDs). However, the number of Galactic OCs with eMSTO structures detected so far is limited, and the reasons for their formation are still unclear. This work identifies 26 Galactic OCs with undiscovered e…
Variable Stars in the 50BiN Open Cluster Survey. III. NGC 884
Deng, Li-Cai; Wang, Kun; Zhang, Xiao-Bin +5 more
Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky Way. Variable stars in open clusters provide a unique way to accurately probe the internal structure, temporal and dynamical evolutionary stages of individual stars and the host cluster. The most powerful tool for such stu…