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New light curve solution of V568 Peg and first determination of its fundamental parameters
Kjurkchieva, Diana; Ibryamov, Sunay
We present V, R_c photometric observations of the short-period W UMa star V568 Peg. They allowed us to improve its period. The light curve solution revealed that V568 Peg is an overcontact binary of A subtype with moderate fill-out factor. Its components are K stars which undergo partial eclipses. The mass ratio was estimated by q-search analysis.…
A Kinematically Cold Structure of Candidate Young OB Stars toward the Anticenter
Casetti-Dinescu, Dana I.; Girard, Terrence M.
We combine Galaxy Evolution Explorer and Gaia DR2 catalogs to track star formation in the outskirts of our Galaxy. Using photometry, proper motions, and parallaxes we identify a structure of ∼300 OB-type candidates located between 12 and 15 kpc from the Galactic center that are kinematically cold. The structure is located between l = 120° and 200°…
Editor's note
Schartel, Norbert
Transient Dimming of the Bright Fe XIV Emission Region in the Solar Corona of the 21 August 2017 Total Solar Eclipse
Liebenberg, D. H.
During the 21 August 2017 total solar eclipse the corona was observed through a narrowband filter centered at the Fe XIV green emission line at a cadence of 30 frames/s. A bright region on the east limb was observed to dim during the 2 m 35 s totality. Details of the temporal behavior of this region are reported. The likely association of the dimm…
Data-Driven Pixelation with Voronoi Tessellation
Lam, Marco C.; McWhirter, Paul R.
In modern Astrophysics, Voronoi Tessellation is a rarely used as a pixelation scheme. While it exists, it is almost exclusively used in signal enhancements, clustering analysis, and simulations. In observational Astronomy, with Gaia, ZTF, DES, etc. data becoming available, this branch of science is becoming more and more data-driven. HEALPix offer…
Alignment procedure for the Gregorian telescope of the Metis coronagraph for the Solar Orbiter ESA mission
Susino, Roberto; Antonucci, Ester; Fineschi, Silvano +20 more
Metis is a solar coronagraph mounted on-board the Solar Orbiter ESA spacecraft. Solar Orbiter is scheduled for launch in February 2020 and it is dedicated to study the solar and heliospheric physics from a privileged close and inclined orbit around the Sun. Perihelion passages with a minimum distance of 0.28 AU are foreseen. Metis features two cha…
Strong southward and northward currents observed in the inner plasma sheet
Shen, Chao; Ji, Yong; Yang, Yan-Yan
It is generally believed that field-aligned currents (FACs) and the ring current (RC) are two dominant parts of the inner magnetosphere. However, using the Cluster spacecraft crossing the pre-midnight inner plasma sheet in the latitudinal region between 10 and 30∘ N, it is found that, during intense geomagnetic storms, in addition to FA…
Characterization of eclipsing binaries in High Latitude Field 356
Smits, Derck P.; Skelton, P. L.
Variable stars in HLF 356 identified from plates taken at Harvard Observatory southern station in the 1930s are characterised using data from the ASAS, SuperWASP and Catalina Sky Survey databases. Very little work has been done on these variables since their discovery. Their periods are determined, and light curves for these stars are presented, f…
Promising Neutron Detector with Anticoincidence Protection
Mitrofanov, I. G.; Litvak, M. L.; Sanin, A. B. +6 more
The method of remote neutron and gamma spectrometry of bodies in the solar system (the Moon, Mars, and Mercury) has been used for several decades to estimate the nuclear composition of these objects and the hydrogen abundance in their subsurface layers. Proportional gas counters based on helium-3 (3He), which have the maximum efficiency…
New Astrometric Reduction of the Supercosmos Plate Archive: First Results
Andruk, V. M.; Akhmetov, V. S.; Protsyuk, Yu. I. +2 more
The arrivals of the new more accuracy reference catalogs and development of new methods and approaches for reduction astrometric data give the new life for photographic plates archives. Gaia DR2 is not only a giant step in the astrometric accuracy allowing to measure new objects it also provides plates archives observed in the past with modern acc…