Search Publications
A Search for Exoplanets in Open Clusters and Young Associations based on TESS Objects of Interest
Mann, Andrew W.; Gan, Tianjun; Sun, Qinghui +1 more
We report the results of our search for planet candidates in open clusters and young stellar associations based on the Transiting Exoplanet Survey Satellite (TESS) Objects of Interest Catalog. We find one confirmed planet, one promising candidate, one brown dwarf and three unverified planet candidates in a sample of 1229 open clusters from the sec…
The Astrometric Performance Test of 80 cm Telescope at Yaoan Station and Precise CCD Positions of Apophis
Guo, Bifeng; Peng, Qingyu; Chen, Ying +4 more
The 80 cm azimuthal telescope has newly been mounted at Yaoan Station, Purple Mountain Observatory since 2018. The astrometric performance of the telescope is tested in the following three aspects. (a) The geometric distortion of its CCD attached. It is stable in both a single epoch and multi epochs. Eight distortion solutions are derived over abo…
V0644 Ser: An Active Ultrashort Period Contact Binary Star
Zhu, Li-Ying; Xu, Hu-Shan; Thawicharat, Sarotsakulchai +1 more
The photometric solutions of the ultrashort period close binary V0644 Ser based on our new complete BVRI light curves are derived by the Wilson-Devininney code. The results show that V0644 Ser is a W-type shallow contact binary, and the third light was found in the R and I bands. Compared with the light curves in 2011, the amplitude variation of t…
B3 0749+460A: A New Repeat "Changing-look" Active Galactic Nucleus Associated with X-Ray Spectral Slope Variations
Filippenko, A. V.; Wang, J.; Gao, C. +5 more
Here we report an identification of B3 0749+460A as a new double-peaked local "changing-look" active galactic nucleus (CL-AGN) in terms of our multi-epoch spectroscopic analysis. By comparing our new spectra taken in 2021 with the ones taken by the Sloan Digital Sky Survey in 2004, BOSS in 2013 and MaNGA in 2016, we reveal type transitions of Seyf…
Application of Random Forest Regressions on Stellar Parameters of A-type Stars and Feature Extraction
He, Ying; Chen, Shu-Xin; Sun, Wei-Min
Measuring the stellar parameters of A-type stars is more difficult than FGK stars because of the sparse features in their spectra and the degeneracy between effective temperature (T eff) and gravity (log g). Modeling the relationship between fundamental stellar parameters and features through machine learning is possible because we can …
Herschel Investigation of Cores and Filamentary Structures in the Perseus Molecular Cloud
Zhang, Guo-Yin; Zhang, Chang; Li, Jin-Zeng +1 more
Cores and filamentary structures are the prime birthplaces of stars, and play key roles in the process of star formation. Latest advances in the methods of multi-scale source and filament extraction, and in making high-resolution column density map from Herschel multi-wavelength observations enable us to detect the filamentary network structures i…
A Photometric Study of Two Contact Binaries: CRTS J025408.1+265957 and CRTS J012111.1+272933
Hu, Qingshun; Zhang, Yu; Ma, Shuo +2 more
We performed new photometric observations for two contact binaries (i.e., CRTS J025408.1+265957 and CRTS J012111.1+272933), which were observed by the 1.0 m telescope at Xingjiang Astronomical Observatory. From our light curves and several survey data, we derived several sets of photometric solutions. We found that CRTS J025408.1+265957 and CRTS J…
X-Ray and Radio Studies of the Candidate Millisecond Pulsar Binary 4FGL J0935.3+0901
Zheng, Dong; Wang, Zhong-Xiang; Xing, Yi +1 more
4FGL J0935.5+0901, a γ-ray source recently identified as a candidate redback-type millisecond pulsar (MSP) binary, shows an interesting feature of having double-peaked emission lines in its optical spectrum. This feature would further suggest the source is a transitional MSP system in the sub-luminous disk state. We have observed the source with X…
Photometric Investigation of Contact Binary DY Cet Based on TESS Data
Yıldırım, M. F.
We present a photometric analysis of the Transiting Exoplanet Survey Satellite (TESS) light curve of contact binary system DY Cet and the behavior of its orbital period variation. The light curve and published radial velocity data analysis was performed using the Wilson-Devinney code. As a result of simultaneous analysis of the light curve with ra…
Can Turbulent, High-density Gas Form Stars in Molecular Clouds: A Case Study in Ophiuchus
Tsai, Chao-Wei; Lin, Yuxin; Wu, Jingwen +3 more
Star formation is governed by the interplay between gravity and turbulence in most of molecular clouds. Recent theoretical works assume that dense gas, whose column density is above a critical value in the column density probability distribution function (N-PDF), where gravity starts to overcome turbulence, becomes star-forming gas and will collap…