Search Publications
Magnetic flux participation in solar surface magnetism during solar cycle 24
Wang, Jing-Xiu; Jin, Chun-Lan
This study aims at investigating surface magnetic flux participation among different types of magnetic features during solar cycle 24. State-of-the-art observations from SDO/HMI and Hinode/SOT are combined to form a unique database in the interval from April 2010 to October 2015. Unlike previous studies, the statistics presented in this paper are …
CN Andromedae: a shallow contact binary with a possible tertiary component
Soydugan, Faruk; Aliçavuş, Fahri; Yildirim, Muhammed Faruk
In this study, new photometric observations of shallow contact binary CN Andromedae (CN And) were performed and multi-color (BV R) CCD light curves (LCs) were obtained. Simultaneous analysis of new LCs and published radial velocity (RV) data reveals that the system is an early contact binary in which both components have recently filled their inne…
IU Cancri: a solar-type contact binary with mass transfer
Dai, Hai-Feng; Yuan, Hui-Yu; Yang, Yuan-Gui
We present new CCD photometry of the solar-type contact binary IU Cnc, which was observed from November 2017 to March 2018 with three small telescopes in China. BV light curves imply that IU Cnc is a W-type contact binary with total eclipses. The photometric solution indicates that the mass ratio and fill-out factor are q = 4.104 ± 0.004 and f = 3…
X-ray activity from different types of stars
Zhang, Yong; Soria, Roberto; Bai, Yu +10 more
X-ray emission is an important indicator of stellar activity. In this paper, we study stellar X-ray activity using the XMM-Newton and LAMOST data for different types of stars. We provide a sample including 1259 X-ray-emitting stars, of which 1090 have accurate stellar parameter estimations. Our sample size is much larger than those used in previou…
Resource potential and planning for exploration of the Hebrus Valles, Mars
Yadav, Santosh Kumar; Srivastava, Neeraj; Sharma, Ravi
Mars is the only extraterrestrial body which could host primitive lifeforms and also has the potential to host a human base in the near future. Towards fulfilling these objectives, several remote sensing missions and rover based missions have been sent to Mars. Still, confirmation of existing or extinct life on this planet in any form has not been…
Unusual infrared emission toward Sgr B2: possible planar C24
Li, Aigen; Xiang, Fu-Yuan; Yang, Xue-Juan +1 more
Interstellar graphene could be present in the interstellar medium (ISM), resulting from the photochemical processing of polycyclic aromatic hydrocarbon (PAH) molecules and/or collisional fragmentation of graphitic particles. Indeed, by comparing the observed ultraviolet (UV) extinction and infrared (IR) emission of the diffuse ISM with that predic…
A new method to determine the gravity field of small bodies from line-of-sight acceleration data
Barriot, Jean-Pierre; Rodriguez, J. Alexis P.; Yan, Jian-Guo +2 more
We present a new method to derive line-of-sight acceleration observables from spacecraft radio tracking data. The observables can be used to estimate the mass and gravity of a natural satellite as a spacecraft flyby. The corresponding observation model adapts to one-way and two/three-way tracking modes. As a test case for method validation and app…
CCD astrometric observations of 2017 VR12, Camillo and Midas
Su, Jie; Wang, Jian-Cheng; Zhang, Yi-Gong +2 more
We have observed three near-Earth objects (NEOs), 2017 VR12, Camillo and Midas, during 2018. The observations were made with the 1-m telescope, operated by Yunnan Observatories, over two nights. Their precise astrometric positions are derived from 989 CCD observations. The theoretical positions of asteroids are retrieved from the Jet Propulsion La…
The Y SZ,Planck - Y SZ,XMM scaling relation and its difference between cool-core and non-cool-core clusters
Zhao, Hai-Hui; Jia, Shu-Mei; Chen, Yong +3 more
We construct a sample of 70 clusters using data from XMM-Newton and Planck to investigate the Y SZ,Planck - Y SZ,XMM scaling relation and the cool-core influences on this relation. Y SZ,XMM is calculated by accurately de-projected temperature and electron number density profiles derived from XMM-Newton. Y S…
Variable binaries and variables in binaries in the Binary star DataBase
Malkov, Oleg; Kovaleva, Dana; Kaygorodov, Pavel
The Binary star DataBase (BDB, http://bdb.inasan.ru) combines data from catalogs of binary and multiple stars of all observational types. There is a number of ways for variable stars to form or to be a part of binary or multiple systems. We describe how such stars are represented in the database.