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A New X-Ray Tidal Disruption Event Candidate with Fast Variability
Greiner, J.; Komossa, S.; Erben, T. +3 more
During a close encounter between a star and a supermassive black hole, the star can get disrupted by the black hole's tidal forces, resulting in a tidal disruption event (TDE). The accretion of the star's material onto the black hole produces strong emission in different wavelength regimes. Here we report the discovery with the Roentgen Satellite …
Super-resolution of Solar Magnetograms Using Deep Learning
Xu, Long; Zhao, Dong; Dou, Fengping +2 more
Currently, data-driven models of solar activity forecast are investigated extensively by using machine learning. For model training, it is highly demanded to establish a large database which may contain observations coming from different instruments with different spatio-temporal resolutions. In this paper, we employ deep learning models for super…
The Role of Magnetic Fields in Triggered Star Formation of RCW 120
Chen, Zhiwei; Sefako, Ramotholo; Jiang, Zhibo +3 more
We report on the near-infrared polarimetric observations of RCW 120 with the 1.4 m IRSF telescope. The starlight polarization of the background stars reveals for the first time the magnetic field of RCW 120. The global magnetic field of RCW 120 is along the direction of 20°, parallel to the Galactic plane. The field strength on the plane of the sk…
Precise Evolutionary Asteroseismology of High-Amplitude δ Scuti Star AE Ursae Majoris
Fu, Jian-Ning; Xue, Hui-Fang; Niu, Jia-Shu
Stellar structure and evolution theory is one of the bases in modern astronomy. Stellar inner structures and their evolutionary states can be precisely tested by asteroseismology, since the inner information is brought to the stellar surface by the global oscillating waves and becomes observable. For stellar evolutionary speed (i.e., how long time…
The Relative Orientation between Local Magnetic Field and Galactic Plane in Low Latitude Dark Clouds
Wolf, S.; Pandey, J. C.; Choudhury, Gulafsha B. +4 more
In this work, we study the magnetic field morphology of selected star-forming clouds spread over the galactic latitude (b) range -10° to 10°. The polarimetric observations of clouds CB24, CB27 and CB188 are conducted to study the magnetic field geometry of those clouds using the 104 cm Sampurnanand Telescope (ST) located at ARIES, Manora Peak, Nai…
Physical Properties of 29 sdB+dM Eclipsing Binaries in Zwicky Transient Facility
Wang, Shu; Deng, Li-Cai; Wang, Kun +3 more
The development of large-scale time-domain surveys provides an opportunity to study the physical properties as well as the evolutionary scenario of B-type subdwarfs (sdBs) and M-type dwarfs (dMs). Here, we obtained 33 sdB+dM eclipsing binaries based on the Zwicky Transient Facility (ZTF) light curves and Gaia Early Data Release 3 (EDR3) parallaxes…
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…