Search Publications
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…
Discovery of 2716 hot emission-line stars from LAMOST DR5
Mathew, Blesson; Kartha, Sreeja S.; Kumar, Yerra Bharat +4 more
We present a catalog of 3339 hot emission-line stars (ELSs) identified from 451 695 O, B and A type spectra, provided by LAMOST Data Release 5 (DR5). We developed an automated Python routine that identified 5437 spectra having a peak between 6561 and 6568 Å. False detections and bad spectra were removed, leaving 4138 good emission-line spectra of …
Stellar loci IV. red giant stars
Yuan, Hai-Bo; Huang, Yang; Chen, Bing-Qiu +3 more
In the fourth paper of this series, we present the metallicity-dependent Sloan Digital Sky Survey (SDSS) stellar color loci of red giant stars, using a spectroscopic sample of red giants in the SDSS Stripe 82 region. The stars span a range of 0.55 - 1.2 mag in color g - i, -0.3 - -2.5 in metallicity [Fe/H], and have values of surface gravity log g…