Search Publications
Combined penalized weights based GM-PHD for point target tracking in starry-sky background
Luo, Qingqing; Gao, Zhisheng; Xie, Chunzhi
It is well known that the point targets observed by the space-based platform are extremely difficult to track due to the interference of a large number of stellar targets and background noise. The traditional GM-PHD, due to its probability accumulation, is easy to mistakenly identify the star as a derived new target when the real target passes clo…
Dissecting the Strong-lensing Galaxy Cluster MS 0440.5+0204. I. The Mass Density Profile
Limousin, Marceau; Carrasco, Eleazar R.; de Diego, José A. +5 more
We present a parametric strong-lensing modeling of the galaxy cluster MS 0440.5+0204 (located at z = 0.19). We have performed a strong-lensing mass reconstruction of the cluster using three different models. The first model uses the image positions of four multiply imaged systems (providing 26 constraints). The second one combines strong-lensing c…
Close eclipsing binary BD And: a triple system
Perdelwitz, V.; Kundra, E.; Guenther, E. +5 more
BD And is a fairly bright (V = 10.8), active and close (P ∼ 0.9258 days) eclipsing binary. The cyclic variability of the apparent orbital period as well as third light in the light curves indicate the presence of an additional late-type component. The principal aim is the spectroscopic testing of the third-body hypothesis and determination of abso…
Pulsation mode switching in the pulsating star HD 81589 and a proposed classification as a field FaRPB star
Martinez, P.; van Heerden, P.; Engelbrecht, C. A.
Extensive multicolour photometry and low-resolution spectroscopy obtained for HD 81589 place the star in the gap between δ Scuti and slowly pulsating B pulsators on the main sequence. A clear episode of pulsation mode switching has apparently occurred in HD 81589, with its primary pulsation frequency switching from 4.57 to 3.71 c d-1 in…
Prospects of Ground-Based and Orbital Studies of Comets and Meteors in the Post-Rosetta Mission Era
Sachkov, M. E.
In this paper, we review the current state and prospects of comet and meteor studies. Special attention is paid to scientific tasks that should be solved with a help of space missions.
The Galactic Aberration and Its Impact on Astronomical Reference Frames
Liu, Jia-cheng; Liu, Niu
The Galactic aberration effect, also known as the secular aberration drift, is a consequence of the centripetal acceleration of the Solar System Barycenter in the circular orbit around the Galactic center. It causes distance-independent apparent proper motions (the amplitude is about 5 µas · yr - 1) for extragalactic sources which…
First Space and Kinematical Analysis of Newly Discovered Southern UFMGs Clusters with Gaia
Elsanhoury, W. H.
The work on the kinematical parameters and spatial shape structure have been performed with Gaia DR2 astrometry data of the new recently southern discovered open clusters UFMG 1, UFMG 2, and UFMG 3 in the vicinity (∼1.3 degrees radius) of the rarely studied NGC 5999. The apexes positions with AD-diagram method are computed for about 107, 168, 98, …
X-ray astronomy in 2019
Elvis, Martin
Every 10 years, X-ray astronomers gather in Bologna, Italy, to review the state of the field. After 30 years of these meetings, is there really still a separate field of X-ray astronomy?
Formation and Evolutionary Changes of Coronal Holes in the Growth Phase of Cycle 23
Bilenko, I. A.; Tavastsherna, K. S.
The regularities in the formation of coronal holes in the growth phase of cycle 23 are studied. The period from January 1, 1997, to March 1, 2000 (Carrington rotations 1918–2059), is considered in detail. The evolution of the global magnetic field of the Sun from a zonal to a sectorial structure of the field distribution is analyzed. The zonal str…
Revisiting astrometric parameters of quasars in Gaia-CRF2
Liu, N.; Zhu, Z.; Liu, J. -C. +1 more
Aims: In order to check the astrometric solution quality, dependences of parallaxes and proper motions on precision, reliability, and consistency of sample solutions are studied for the quasars in the celestial reference frame of the second release of Gaia data (Gaia-CRF2).
Methods: Astrometric statistics (the number of visibility period…