Search Publications
Ensemble Numerical Simulations of Realistic SEP Events and the Inspiration for Space Weather Awareness
Li, Gang; Wang, Xin; Luo, Bingxian +5 more
The solar energetic particle (SEP) event is a kind of hazardous space weather phenomena, so its quantitative forecast is of great importance from the aspect of space environmental situation awareness. We present here a set of SEP forecast tools, which consists of three components : (1) a simple polytropic solar wind model to estimate the backgroun…
The First Photometric Study of W UMa Binary System V1833 Ori
Tanrıver, Mehmet; Bulut, Ahmet
The first photometric solution in the B, V, R c and I c filters of the short period V1833 Ori eclipsing binary is presented based on new ground-based CCD photometric observations. We analyzed the BVRI photometric light curves of the system, using PHOEBE 0.31a, a binary star modeling program, with the Wilson-Devinney metho…
A catalogue of 74 new open clusters found in Gaia Data-Release 2
Xu, Ye; Li, Jing-Jing; Wu, Zhen-Yu +2 more
Based on astrometric data from Gaia Data-Release 2 (DR2), we employ an unsupervised machine learning method to blindly search for open star clusters in the Milky Way within the Galactic latitude range of |b| < 20°. In addition to 2080 known clusters, 74 new open cluster candidates are found. In this work, we present the positions, apparent radi…
How much has the Sun influenced Northern Hemisphere temperature trends? An ongoing debate
Henry, Gregory W.; Solheim, Jan-Erik; Scafetta, Nicola +20 more
In order to evaluate how much Total Solar Irradiance (TSI) has influenced Northern Hemisphere surface air temperature trends, it is important to have reliable estimates of both quantities. Sixteen different estimates of the changes in TSI since at least the 19th century were compiled from the literature. Half of these estimates are "low…
An Earth-mass planet in a time of COVID-19: KMT-2020-BLG-0414Lb
Maoz, Dan; Tan, Thiam-Guan; Han, Cheongho +58 more
We report the discovery of KMT-2020-BLG-0414Lb, with a planet-to-host mass ratio q 2 = 0.9-1.2 × 10-5 = 3-4 ⊕ at 1σ, which is the lowest mass-ratio microlensing planet to date. Together with two other recent discoveries (4 ≲ q/q ⊕ ≲ 6), it fills out the previous empty sector at the bottom of the triangular (log s, …
LAMOST Time-Domain survey: first results of four K2 plates
Tian, Hao; Kovalev, Mikhail; Fu, Jian-Ning +23 more
From Oct. 2019 to Apr. 2020, LAMOST performed a time-domain (TD) spectroscopic survey of four K2 plates with both low- and medium-resolution observations. The low-resolution spectroscopic survey acquired 282 exposures ( ≈ 46.6 h) over 25 nights, yielding a total of about 767 000 spectra, and the medium-resolution survey took 177 exposures ( ≈ 49.1…
Orbits of 152 globular clusters of the MilkyWay galaxy constructed from Gaia DR2
Bajkova, Anisa Talgatovna; Bobylev, Vadim Vadimovich
We present orbits and their properties for 152 globular clusters of the Milky Way galaxy obtained using average Gaia DR2 proper motions and other astrometric data from the list of Vasiliev. For orbital integration we have applied the axisymmetric model of the Galactic potential based on the Navarro-Frenk- White dark halo, and modified by Bajkova &…
New open clusters found by manual mining of data based on Gaia DR2
Casado, Juan
The physical nature of a series of 20 new open clusters is confirmed employing existing data on putative star members, mainly from the second Gaia Data Release (DR2). The clusters were discovered as overdensities of stars by visual inspection of either photographic DSS plates or proper motion plots of random source fields. The reported objects are…
Discovery of Four New Clusters in the Cygnus Cloud
Chen, Li; Zhong, Jing; Li, Jing +1 more
We report the discovery of four new open clusters (named QC 1, QC 2, QC 3 and QC 4) in the direction of Cygnus Cloud and select their members based on five astrometric parameters (l, b, ϖ, ${\mu }_{\alpha }^{* }$ , µδ) of Gaia DR2. We also derive their astrophysical parameters for each new cluster. Structure parameters are generat…
Physical and geometrical parameters of CVBS XIV: the two nearby systems HIP 19206 and HIP 84425
Mardini, Mohammad K.; Al-Wardat, Mashhoor A.; Hussein, Abdallah M. +6 more
Data release 2 (DR2) from the Gaia mission was of great help in precise determination of fundamental parameters of Close Visual Binary and Multiple Systems (CVBMSs), especially masses of their components, which are crucial parameters in understanding formation and evolution of stars and galaxies. This article presents the complete set of fundament…