Search Publications
Discovery of 226 δ γ
Zhou, Ai-Ying
We present the discovery of 269 pulsating variable stars of
Spectroscopic and photometric study for five late G- to K-type short-period contact binaries
Michel, Raúl; Mora Zamora, I.; Wang, Zhi-Hua +1 more
We reported spectroscopy and photometry for five ultra-short period W UMa-type contact binaries. Eleven sets of low resolution spectra are obtained from the Large Sky Area Multiobject Fiber Spectroscopic Telescope (LAMOST) database and analyzed. It has been determined that these systems are late G- to K-type stars: G7V for J0658, G9V for LINEAR 35…
Estimation of classical Cepheid's physical parameters from NIR light curves
Balázs, Lajos G.; Kovács, Gábor B.
Recent space-borne and ground-based observations provide photometric measurements as time series. The data points are nearly continuous over a limited observational interval or randomly scattered over a long period. The effect of interstellar dust extinction in the near-infrared range is only 10% of that measured in the visual (V) range. However, …
The distortion solution for the 1-m telescope at Yunnan Observatory and its application to the positional measurement of four main-belt asteroids Eugenia(45), Roma(472), Lundmarka(1334) and Autonoma(1465)
Wang, Na; Liu, Kai-Rui; Xue, Zheng-Yang +2 more
Four main-belt asteroids Eugenia, Roma, Lundmarka and Autonoma were observed at Yunnan Observatory 1-m telescope in 2022–2023. A total of 66 CCD frames for the four asteroids are observed. In order to improve the astrometry, the geometric distortion (called GD hereafter) of the 1-m telescope is solved. After GD correction, the precision of Eugenia…
How inclusion of binaries affects the fitting of giant branches and determination of fundamental parameters of star clusters
Li, Zhongmu; Zhou, Yun
Open clusters (OCs) play an important role in the study of star formation and the structural evolution of the Milky Way. This paper fits the color-magnitude diagrams (CMDs) of 17 OCs using a tool called Powerful CMD, with the aim of studying the effect of inclusion of binary stars on the fitting of cluster CMDs with clear giant branches. The fitti…
Study of solar activities associated with a Halo CME on 17 Feb 2023 event
Ahamed, A. Ansar; Subramanian, S. Prasanna; Rahman, A. Mujiber +3 more
In the present work, propagation of an earth directed fast and wide Coronal Mass Ejection event on 17 February 2023 is studied in detail. The complex magnetic configuration in the Active Region (AR) 13229 at N25E64 caused an intensive X2.3 flare with a peak at 19:38 UT. It is followed by a massive halo CME event observed in the LASCO C3 coronagrap…
Hints of point-symmetric structures in SN 1987A: The jittering jets explosion mechanism
Soker, Noam
I identify a point-symmetric structure composed of three pairs of clumps in the recently released JWST image of the ejecta of SN 1987A and argue that these pairs of clumps support the jittering jets explosion mechanism (JJEM) for SN 1987A. I compare this point-symmetric structure with the multipolar-lobe morphology of a post-asymptotic giant branc…
Unveiling δ Scuti and γ Doradus hybrid pulsation of HD 53166 and HD 53349 plus rich frequencies in HD 52788
Zhou, Ai-Ying
We present discoveries of the hybrid δ Scuti and γ Doradus types stellar pulsational variability of two stars, HD 53166 and HD 53349, which were previously used as comparison in the differential photometry of a known δ Scuti star HD 52788. More surprisingly, HD 52788 exhibits 126 pulsation frequencies in a small domain in 4-12 d-1 based…
Estimating the absolute parameters of W UMa-type binary stars using Gaia DR3 parallax
Poro, Atila; Nourmohammad, Mahshid; Hedayatjoo, Mahya +7 more
The accuracy of absolute parameters' estimation in contact binary systems is important for investigating their evolution and solving some challenges. The Gaia DR3 parallax is one of the methods used for estimating the absolute parameters, in cases where photometric data is the only one that is available. The use of this method includes advantages …
Discovery of four new EL CVn-type binaries in the Gaia eclipsing binaries
Wang, Kun; Ren, Anbing; Peng, Yuhui
In this paper, we performed a search for EL CVn-type binaries based on the Gaia and TESS data. Through the combination of the Gaia DR3 eclipsing binary catalogue and the Gaia DR3 spectroscopic binary catalogue, we have identified 13 stars exhibiting EL CVn-like characteristics. Among these stars, nine have already been identified as EL CVn binarie…