We present the developed methods of digitization, image processing, reduction, and scientific data mining with the latest reference catalogs, which allowed us to obtain a good positional and photometric accuracy in B-band of 6,500 asteroids down to 17.5 m from the Ukrainian Virtual Observatory database of astroplates. The archive includes FON-Kyiv, FON-Kitab, FON-Dushanbe sky surveys (1981–1996) and astroplates of the Baldone and Tautenburg observatories. For some of asteroids, observations are either completely absent or not enough over the certain time interval to the moments of their official discoveries (about 300 such objects were found). Positional observations during these time scales are highly useful for a more detailed study of the dynamics and orbital parameters of asteroids as well as the obtained photometric parameters are very complementary with present-day data for studying changes in brightness and light curves.

The need for accurate photometric redshifts estimation is a topic that has fundamental importance in Astronomy, due to the necessity of efficiently obtaining redshift information without the need of spectroscopic analysis. We propose a method for determining accurate multi-modal photo-z probability density functions (PDFs) using Mixture Density Networks (MDN) and Deep Convolutional Networks (DCN). A comparison with a Random Forest (RF) is performed.

The research of stars with the B[e] phenomenon is still in its infancy, with several unanswered questions. Physically realistic models that treat the formation and evolution of their complex circumstellar environments are rare. The code HDUST (developed by A. C. Carciofi and J. Bjorkman) is one of the few existing codes that provides a self-consistent treatment of the radiative transfer in a gaseous and dusty circumstellar environment seen around B[e] supergiant stars. In this work we used the HDUST code to study the circumstellar medium of the binary system GG Car, where the primary component is probably an evolved B[e] supergiant. This system also presents a disk (probably circumbinary), which is responsible for the molecular and dusty signatures seen in GG Car spectra. We obtained VLTI/MIDI data on GG~Car at eight baselines, which allowed to spatially resolve the gaseous and dusty circumstellar environment. From the interferometric visibilities and SED modeling with HDUST, we confirm the presence of a compact ring, where the hot dust lies. We also show that large grains can reproduce the lack of structure in the SED and visibilities across the silicate band. We conclude the dust condensation site is much closer to the star than previously thought. This result provides stringent constraints on future theories of grain formation and growth around hot stars.

With SDSS multi-bands photometric data we propose that the variation of the nuclear continuum emission mostly accounts for the observed wavelength-dependent variability of active galactic nuclei.

Since 2010, a program to explore new eclipsing binary systems identified from STEREO photometry has been in progress. Our first results are presented here: light curves and high resolution spectra taken with Coudé spectrograph (National Astronomical Observatory Rozhen) and ARC Échelle spectrometer (ARCES, Apache Point Observatory).

Extrasolar planets in binary and multiple star systems have become a noticeable niche with about 50 planets among over 500 known. Here we however focus on a particular subset of exoplanets in binary star systems — circumbinary planets. They have the unique advantage that a search for circumbinary planets does also significantly contribute to the understanding of their parent stars. We review what is currently known about circumbinary planets and then introduce our two projects aimed at detecting circumbinary planets: The TATOOINE project to find circumbinary planets around non-eclipsing double-lined spectroscopic binary stars with precision radial velocities, and the SOLARIS project to detect circumbinary planets with the timing of eclipses of eclipsing binary stars. For the SOLARIS project, we were granted 2.6 million USD to establish a network of at least four robotic 0.5-m telescopes on three continents (Australia, Africa and South America) to carry out precision photometry of a sample of eclipsing binary stars. We expect that both projects will have a large impact also on the observational stellar astronomy.

Every ten years the astronomy and astrophysics community in the United States undertakes a survey intended to prioritize plans for major ground- and space-based astronomical facilities for the coming decade. New Worlds, New Horizons (NWNH) was released in August 2010 and represents the community's advice to the United States' funding agencies about the top priorities for 2010-2020. Here we focus on the recommendations of NWNH for space-based exoplanet missions to be considered by NASA, and on the plans developed to date for how NASA will respond to the science goals and missions set out for them by NWNH.

The PRIMA (Phase-Referenced Imaging and Micro-arcsecond Astrometry) facility at ESO VLTI (Paranal observatory) is expected to be commissioned in mid 2008. The ESPRI (Exoplanet Search with PRIMA) consortium is currently preparing an astrometric survey to search for extrasolar planets. To achieve the scientific goal of this survey, a careful selection of target and reference stars is necessary. Apart from catalog search and modelling, extensive and dedicated preparatory observations are indispensable. Here we present two aspects of the preparatory observation programs: A high dynamic range near infrared (NIR) imaging survey to search for astrometric reference stars around the preselected target stars and characterization of the target stars by using high-resolution spectroscopy.

We have started a VLBI monitoring program for Asymptotic Giant Branch (AGB) stars at 22 and 43 GHz as part of a project of the VLBI Exploration of Radio Astrometry (VERA) for precisely obtaining the period-luminosity (PL) relation of Galactic Mira variables. Using accurate distances measured with VERA, we reveal PL relation in the Galaxy based on the absolute magnitudes of the sources. We selected the sources for VLBI monitoring so that they have a good coverage of various pulsation periods. Photometry in the infrared J, H, and K bands for over 600 AGB stars has also started since 2003 with the 1m telescope of Kagoshima University to obtain the pulsation periods and magnitudes. Current analysis of the phase referencing VLBI observations of S Crt shows that the parallax of 2.3±0.2 milliarcsec (mas) corresponds to a distance of 435+41−35 pc. From the infrared monitoring data, pulsation periods and magnitudes in K band for 248 sources were obtained.

New uvby photoelectric photometry has been acquired for the triple star DG Leo at two different observatories equipped with analogous instrumentation. A preliminary period analysis indicates the presence of at least 3 close δ Scuti frequencies (10-12 c/d, 3-6 mmag) and a slow variation. This slow variation fits quite well with half the orbital period of the spectroscopic binary; the noise level in the amplitude spectrum is only 3–4 mmag (after prewhitening).

Following our high speed photometric survey of faint cataclysmic variables, two CVs were recognised to be helium-transferring double degenerates; these are ES Cet (Рorb – 620.21144 s) and 2003aw (Psh= 2041.5 s). We have now observed ES Cet photometrically for over two years in order to follow the evolution of the orbital period. We oiler an alternative; explanation for the nature of V407 Vul (which was classified as an ultra-compact together with RX J0806 and ES Cet); this will take V407 Vul out of the AM CVn classification.