Search Publications
Symbiotic Nature of the Zirconium Star CSS 1102
Ikonnikova, N. P.; Tatarnikov, A. M.; Dodin, A. V. +2 more
Based on the spectroscopic observations carried out with the 2.5-m telescope at the Caucasus Mountain Observatory (CMO) of the Sternberg Astronomical Institute (SAI), we have established the symbiotic nature of the poorly studied S star CSS 1102. The Balmer jump in emission is observed in the object's spectrum, and there are lines typical for gase…
Orbit determination methods for interplanetary missions: development and use of the Orbit14 software
Schettino, Giulia; Serra, Daniele; Tommei, Giacomo +1 more
In the last years, a new generation of interplanetary space missions have been designed for the exploration of the solar system. At the same time, radio-science instrumentation has reached an unprecedented level of accuracy, leading to a significant improvement of our knowledge of celestial bodies. Along with this hardware upgrade, software produc…
On the Nature of the Photospheric Horizontal Magnetic Field Increase in Major Solar Flares
Wang, Yuming; Sun, Xudong; Liu, Lijuan +2 more
The rapid increase of the horizontal magnetic field (B h ) around the flaring polarity inversion line is the most prominent photospheric field change during flares. It is considered to be caused by the contraction of flare loops, the details behind which is still not fully understood. Here we investigate the B h increase i…
A New Approach to Kinetic Energy Flux at the Different Frequencies above the IRIS Bright Points
Tavabi, Ehsan; Sadeghi, Rayhane
Various bright structures abound in the chromosphere playing an essential role in the dynamics and evolution therein. Tentatively identifying the wave characteristics in the outer solar atmosphere helps to understand this layer better. One of the most significant aspects of these characteristics is the wave phase speed (PS), which is a dominant co…
Evidence for thermokarst depressions on comet 67P/Churyumov-Gerasimenko: An interplanetary comparison
Jorda, L.; Groussin, O.; Bouley, S. +3 more
Aims: The nucleus of comet 67P/Churyumov-Gerasimenko (67P) is ice rich and shows evidence of morphologies driven by sublimation processes. In particular, the fine-particle deposits (FPD) that cover its surface reveal depressions of many tens of meters. A detailed analysis of these morphologies and of the properties of the fine-particle deposi…
A search for annihilating dark matter in 47 Tucanae and Omega Centauri
Staveley-Smith, Lister; Bekki, Kenji; Westmeier, Tobias +1 more
A plausible formation scenario for the Galactic globular clusters 47 Tucanae (47 Tuc) and Omega Centauri $(ω$ Cen) is that they are tidally stripped remnants of dwarf galaxies, in which case they are likely to have retained a fraction of their dark matter cores. In this study, we have used the ultra-wide band receiver on the Parkes telescope (Murr…
On survival of dust grains in the sublimation zone of cold white dwarfs
Shestakova, Lyubov I.; Kenzhebekova, Akmaral I.; Serebryanskiy, Aleksander V.
We consider a mechanism for the deposition of dust grains on to the surface of cold white dwarfs (WDs). Calculations show that grains can fall on to a cold WD directly, without reaching the phase of complete evaporation, if the parent bodies and the grains orbit on elongated, close to parabolic, orbits. To this end, we calculated the dynamics of e…
SN 2019va: a Type IIP Supernova with Large Influence of Nickel-56 Decay on the Plateau-phase Light Curve
Wang, Xiaofeng; Zhang, Jujia; Mo, Jun +12 more
We present multiband photometric and spectroscopic observations of the type II supernova, (SN) 2019va, which shows an unusually flat plateau-phase evolution in its V-band light curve. Its pseudo-bolometric light curve even shows a weak brightening towards the end of the plateau phase. These uncommon features are related to the influence of 56…
Automated algorithms to build active galactic nucleus classifiers
Larsson, J.; Falocco, S.; Carrera, F. J.
We present a machine learning model to classify active galactic nuclei (AGNs) and galaxies (AGN-galaxy classifier) and a model to identify type 1 (optically unabsorbed) and type 2 (optically absorbed) AGN (type 1/2 classifier). We test tree-based algorithms, using training samples built from the X-ray Multi-Mirror Mission-Newton (XMM-Newton) catal…
SDSS-IV MaStar: [α/Fe] for the MaNGA Stellar Library from synthetic model spectra
Bizyaev, Dmitry; Law, David R.; Stassun, Keivan G. +11 more
We calculate the α-enhancement ratio [α/Fe] for the Mapping Nearby Galaxies at APO (MaNGA) Stellar Library (MaStar) while also fitting for the fundamental atmospheric parameters effective temperature, surface gravity, and metallicity - Teff, log g, [Fe/H]. This approach builds upon a previous catalogue of stellar parameters, whereby onl…