Search Publications
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 …
A Catalog of 13CO Clumps from the MWISP in l = 10°–20°
Chen, Zhiwei; Jiang, Zhibo; Zeng, Xiangyun +8 more
In this study, we present a catalog of molecular clumps extracted from 13CO (J = 1 ‑ 0) emission data of the Milky Way Imaging Scroll Painting (MWISP) project. The data covers the inner Milky Way within the longitude range 10° ≤ l ≤ 20° and the latitude strip of ∣b∣ ≤ 5.°25. The workflow for the extraction of clumps, namely Facet-SS-3D-…
Preparation for CSST: Star-galaxy Classification using a Rotationally Invariant Supervised Machine Learning Method
Fang, Guanwen; Lin, Zesen; Kong, Xu +6 more
Most existing star-galaxy classifiers depend on the reduced information from catalogs, necessitating careful data processing and feature extraction. In this study, we employ a supervised machine learning method (GoogLeNet) to automatically classify stars and galaxies in the COSMOS field. Unlike traditional machine learning methods, we introduce se…
Digitization of Astronomical Photographic Plates of China and Astrometric Measurement of Single-exposure Plates
Yang, Jing; Yu, Yong; Tang, Zheng-Hong +9 more
From the mid-19th century to the end of the 20th century, photographic plates served as the primary detectors for astronomical observations. Astronomical photographic observations in China began in 1901, and over a century, a total of approximately 30,000 astronomical photographic plates were captured. These historical plates play an irreplaceable…