Search Publications
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…
Spectroscopic Study of Late-type Emission-line Stars Using the Data from LAMOST DR6
Mathew, Blesson; Kartha, Sreeja S.; Shridharan, B. +5 more
Low-mass emission-line stars belong to various evolutionary stages, from pre-main-sequence young stars to evolved stars. In this work, we present a catalog of late-type (F0 to M9) emission-line stars from the LAMOST Data Release 6. Using the scipy package, we created a Python code that finds the emission peak at Hα in all late-type stellar spectra…
A Possible X-ray Quasi-periodic Oscillation in the Narrow-line Seyfert 1 Galaxy Mrk 142
Zhong, Xiao-Gu; Wang, Jian-Cheng; Chen, Yong-Yun +1 more
A possible quasi-periodic oscillation (QPO) at frequency 7.045 × 10‑5 Hz is found in the narrow-line Seyfert 1 galaxy Mrk 142 in the data of XMM-Newton collected on 2020 April 11. We find that the QPO signal is statistically significantly larger than the 5σ level and highly coherent with quality factor Q > 5 at the 0.3–10 keV band by…
High-resolution Observations of Clustered Dynamic Extreme-Ultraviolet Bright Tadpoles Near the Footpoints of Corona Loops
Chitta, L. P.; Wang, Rui; Liu, Ying D. +2 more
An extreme ultraviolet (EUV) close-up view of the Sun offers unprecedented detail of heating events in the solar corona. Enhanced temporal and spatial images obtained by the Solar Orbiter during its first science perihelion enabled us to identify clustered EUV bright tadpoles (CEBTs) occurring near the footpoints of coronal loops. Combining SDO/AI…
Probing the Galactic Halo with RR Lyrae Stars. VI. The Radial Velocity Curve Templates of RRc Stars
Fang, Min; Tian, Haijun; Shi, Jianrong +8 more
We present radial velocity (RV) curve templates of RR Lyrae first-overtone (RRc) stars constructed with the Mg I b triplet and Hα lines using time-domain Medium-Resolution Survey spectra of seven RRc stars from Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Data Release 9. Additionally, we derive the relation between the stella…
Astrometric Observations of NEA 1998 HH49 Using the Daocheng 50 cm Telescope
Peng, Qing-Yu; Xu, Huan; Cheng, Xiang-Ming +3 more
This study details an astrometric observation campaign of the Near-Earth Asteroid 1998 HH49, conducted with the aim of refining our understanding of its physical characteristics. Utilizing the 50 cm telescope located at the Wumingshan Mountain in Daocheng, Sichuan, images were obtained over four nights, from 2023 October 19 to October 22. These ob…
A Photometric and Astrometric Study of Open Star Clusters FSR-163 and Majaess 215 Using Gaia DR3
Tadross, A. L.; Ali, Ola; Osman, A. I. +1 more
We have examined most of the astrophysical properties of the two star clusters, FSR-163 and Majaess 215, using the third data release of the Gaia space mission (Gaia DR3). We utilized the pyUPMASK method to allocate the probabilities of stars' membership candidates. Using the clusters' trigonometric parallaxes of the members with probabilities P &…
All-sky Guide Star Catalog for CSST
Tian, Hao; Wang, Wei; Zhang, Xin +17 more
The China Space Station Telescope (CSST) is a two-meter space telescope with multiple back-end instruments. The Fine Guidance Sensor (FGS) is an essential subsystem of the CSST Precision Image Stability System to ensure the required absolute pointing accuracy and line-of-sight stabilization. In this study, we construct the Main Guide Star Catalog …