Irina Belskaya

V. N. Karazin Kharkiv National University · Institute of Astronomy

Within our international program to obtain accurate physical properties of trans-Neptunian objects (TNOs) we predicted a stellar occultation by the TNO (38628) Huya of the star Gaia DR2 4352760586390566400 (mG = 11.5 mag.) for March 18, 2019. After an extensive observational campaign, we updated the prediction and it turned out to be favorable to c...

The amount of sparse asteroid photometry being gathered by both space- and ground-based surveys is growing exponentially. This large volume of data poses a computational challenge owing to both the large amount of information to be processed and the new methods needed to combine data from different sources (e.g. obtained by different techniques, in...

In this work we aim to investigate the presence of absorption bands around 3.4 μm in the infrared spectra of primitive asteroids. We collected the published reflectance spectra of low-albedo asteroids from the literature and analyzed the 2.4-3.8 μm region using the same techniques. From the initial dataset of 92 asteroids, we restricted our analysi...

We present new photometric observations for twelve asteroids ((122) Gerda, (152) Atala, (260) Huberta, (665) Sabine, (692) Hippodamia, (723) Hammonia, (745) Mauritia, (768) Struveana, (863) Benkoela, (1113) Katja, (1175) Margo, (2057) Rosemary) from the outer part of the main belt aimed to obtain the magnitude-phase curves and to verify geometric a...

We present new photometric observations for twelve asteroids ((122) Gerda, (152) Atala, (260) Huberta, (665) Sabine, (692) Hippodamia, (723) Hammonia, (745) Mauritia, (768) Struveana, (863) Benkoela, (1113) Katja, (1175) Margo, (2057) Rosemary) from the outer part of the main belt aimed to obtain the magnitude-phase curves and to verify geometric a...

Context. Less than one percent of the discovered small Solar System objects have highly inclined orbits ( i > 60°), and revolve around the Sun on near-polar or retrograde orbits. The origin and evolutionary history of these objects are not yet clear. Aims. In this work we study the surface properties and orbital dynamics of selected high-inclinatio...

Less than one percent of the discovered small solar system objects have highly inclined orbits ($i>60^{\circ}$), and revolve around the Sun on near-polar or retrograde orbits. The origin and evolutionary history of these objects are not yet clear. In this work we study the surface properties and orbital dynamics of selected high-inclination objects...

We prepared a preliminary comparative analysis of the asteroid absolute magnitudes between the Kharkiv dataset and the MPC, Pan-STARRS, and PTF datasets. The analysis has shown that the absolute magnitude dataset obtained from the Pan-STARRS survey project is closest to our dataset and can be the most suitable for the determination of diameters or...

We present the first-ever measurements of the surface colors and rotational properties of a recently discovered distant object in an unusual orbit 2016 ND21. In 2017, this object was close to its perihelion, which allowed us to observe it with a 2.0-m telescope at the Peak Terskol observatory. Broadband photometric observations of 2016 ND21 were ca...

We present a review on polarimetric properties of small Solar system bodies. The main results of polarimetric investigations of asteroids, comets, transneptunian objects and Centaurs are discussed focusing on recent findings. We also discuss the polarimetric observations of dust clouds in our Solar system.

Astrophysics and Space Science Library, vol 460

Within our international program to obtain physical properties of Transneptunian objects (TNOs) we predicted a stellar occultation by the TNO (38628) Huya of a very bright star (mv= 10.6 mag) for 2019, March 18 th. After a very extensive astrometric campaign we updated the prediction and it turned out to be favorable to central Europe. Therefore, w...

The values of the phase integral q were determined for asteroids using a numerical integration of the brightness phase functions over a wide phase-angle range and the relations between q and the G parameter of the HG function and q and the G1 , G2 parameters of the HG1G2 function. The phase-integral values for asteroids of different geometric albed...

The values of the phase integral q were determined for asteroids using (i) a numerical integration of the brightness phase functions over a wide phase-angle range and (ii) the relations between q and the G parameter of the HG-function and q and the G1, G2 parameters of the HG1G2-function. The phase-integral values for asteroids of different albedo...

Aims. We studied the rotational properties of the dwarf planet Makemake. Methods. The photometric observations were carried out at different telescopes between 2006 and 2017. Most of the measurements were acquired in BVRI broad-band filters of a standard Johnson-Cousins photometric system. Results. We found that Makemake rotates more slowly than wa...

We have obtained polarimetric measurements of asteroid (101955) Bennu, a presumably primitive near-Earth object (NEO) that is the target of NASA's sample return mission OSIRISREx. During our observing campaign, Bennu was visible from Earth under a wide range of illumination conditions, with phase angle in the range 16°-57°. Together with (3200) Pha...

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A multicolour phase-polarization curve of asteroid (3200) Phaethon has been obtained during the 2017 December apparition by merging measurements taken at the observing station of Calern (France) and at the Rozhen observatory (Bulgaria). All the observations were obtained in the positive polarization branch, the phase angle ranging from 36° to 116°....

We have obtained polarimetric measurements of asteroid (101955) Bennu, a presumably primitive near-Earth object (NEO) that is the target of NASA's sample return mission OSIRIS-REx. During our observing campaign, Bennu was visible from Earth under a wide range of illumination conditions, with phase-angle in the range 16 to 57 degrees. Together with...

Airless bodies are directly exposed to ambient plasma and meteoroid fluxes, making them characteristically different from bodies whose dense atmospheres protect their surfaces from such fluxes. Direct exposure to plasma and meteoroids has important consequences for the formation and evolution of planetary surfaces, including altering chemical makeu...

Asteroid (3200) Phaethon is a Near-Earth Apollo asteroid with an unusual orbit that brings it closer to the Sun than any other known asteroid. Its last close approach to the Earth was in mid-December 2017 and the next one will be on October 2026. Previous rotationally time-resolved spectroscopy of Phaethon showed that its spectral slope is slightly...

We search for possible differences in rotational frequencies, diameters, albedos, and orbital parameters between Trojans belonging to the L4 and L5 swarms using our own observations and literature data. With increasing number of observational data it becomes evident that the L4 and L5 populations have very similar distributions of most parameters w...

Asteroid (3200) Phaethon is a Near-Earth Apollo asteroid with an unusual orbit that brings it closer to the Sun than any other known asteroid. Its last close approach to the Earth was in mid-December 2017 and the next one will be on October 2026. Previous rotationally time-resolved spectroscopy of Phaethon showed that its spectral slope is slightly...

The large program aimed at observing the magnitude-phase dependences is performed at the Institute of Astronomy of V. N. Karazin Kharkiv National University. The main goal is to obtain high quality data both in the linear part and in the region of the opposition effect (OE) down to extremely small phase angles of less than one degree to investigate...

Because of realization of the large program performed at the Institute of Astronomy of V. N. Karazin Kharkiv National University, the high quality magnitude-phase dependences have been obtained for about 85 asteroids of different taxonomic types and the significant differences in the behavior of the opposition effect of asteroids were detected. Mai...

A multi-colour phase-polarization curve of asteroid (3200)~Phaethon has been obtained during the December 2017 apparition by merging measurements taken at the observing station of Calern (France) and at the Rhozen observatory (Bulgaria). All the observations were obtained in the positive polarization branch, the phase angle ranging from 36$^\circ$...

The moderate albedo of asteroid (152) Atala was confirmed based on its magnitude-phase dependence and albedo obtained from occulatation diameter.

In the framework of a 30-night spectroscopic survey of small near-Earth asteroids (NEAs) we present new results regarding the identification of olivine-rich objects. The following NEAs were classified as A-type using visible spectra obtained with 3.6 m NTT telescope: (293726) 2007 RQ17, (444584) 2006 UK, 2012 NP, 2014 YS34, 2015 HB117, 2015 LH, 201...

We present the results of the first-ever visible spectroscopic survey fully dedicated to the small (absolute magnitude H>20) near-Earth asteroid (NEA) population. Observations have been performed at the New Technology Telescope (NTT) of the European Southern Observatory (ESO), during a 30-night Guaranteed Time Observations programme, in the framewo...

We present the results of photometric observations of six Transneptunian objects and three Centaurs, estimations of their rotational periods and corresponding amplitudes. For six of them we present also lower limits of density values. All observations were made using 3.6-m TNG telescope (La Palma, Spain). For four objects -- (148975) 2001 XA255, (2...

A new photometric model with small number of parameters is presented. The model is based on an assumption that there exist such surfaces for which spatial brightness variations caused by small topography undulations can be reproduced exactly by corresponding spatial variations of albedo. This indistinguishability results in a differential equation...

The values of the phase integral were determined for the main asteroid composition types using brightness phase functions in the wide phase angle range from space mission data. We found that the range of phase integral values for asteroids of different composition is within 0.34-0.54 with an average value of 0.42.

The large majority of astronomical observations are based on intensity measurements as a function of either wavelength or time, or both. Polarimetry, a technique which measures the way in which the electromagnetic field associated to the radiation oscillates, does provide further information about the objects that have emitted or scattered the obse...

The dwarf planet (136472) Makemake is one of the largest trans-Neptunian objects discovered to date. Noteworthy, the size and surface temperature of this celestial body put it in a transition region where nitrogen is preferentially lost, while the less volatile methane is retained. Indeed, literature spectra clearly show that the surface of Makemak...

We present the results of the photometric and spectrophotometric properties of the 67P/Churyumov–Gerasimenko nucleus derived with the Optical, Spectroscopic and Infrared Remote Imaging System instrument during the closest fly-by over the comet, which took place on 2015 February 14 at a distance of ∼6 km from the surface. Several images covering the...

Photometry is one of the main techniques for studying the physical properties of asteroids. The large bulk of valuable information on rotation and shapes, sizes and albedos, structural and optical properties of asteroids is provided by photometry, especially during the last decade. We review the progress and some problems in asteroid photometry foc...

We present new observational data for selected main-belt asteroids of different compositional types. The detailed magnitude-phase dependencies including small phase angles (<1 deg) were obtained for these asteroids, namely: (10) Hygiea (down to the phase angle of 0.3 deg, C-type), (176) Iduna (0.2 deg, G-type), (214) Aschera (0.2 deg, E-type), (218...

The results of the in situ exploration of the asteroid (4) Vesta by the Dawn spacecraft open new perspectives in the field of interpretation of remote-sensing polarimetric measurements of asteroids. (4) Vesta has long been known to be the only asteroid exhibiting a cyclic variation of the degree of linear polarization of the sunlight scattered by i...

Trojan asteroids orbit in the Lagrange points of the system Sun-planet-asteroid. Their dynamical stability make their physical properties important proxies for the early evolution of our solar system. To study their origin, we want to characterize the surfaces of Jupiter Trojan asteroids and check possible similarities with objects of the main belt...

In this paper we present the results on the polarimetric and spectroscopic observations of the potentially hazardous Asteroid (214869) 2007 PA8 obtained during its favorable apparition in October–November 2012, when it approached the Earth at the minimal distance of 0.043 AU. Polarimetry was carried out at the NOT in the B, V, R, and I bands coveri...

We present updated classification of 258 trans-neptunian objects (TNOs) and centaurs based on their visible and near-infrared colors. With increasing quality and quantity of color measurements we distinguished again four classes of objects confirming the previous classification into the BB, BR, IR, and RR taxonomic groups. Increasing accuracy of co...

The discovery of a vast population of small bodies in the outer part of the solar system has opened new frontiers in solar system studies. More than 1500 objects orbiting the Sun beyond Neptune have been detected since the first discovery of a transneptunian object (TNO) in 1992 by Jewitt and Luu (1993). The population of TNOs has a complex orbital...

The early 1970s were an era of quick progress in polarimetric studies of atmosphereless solar system bodies. Some basic results coming from new observation campaigns and laboratory experiments can be found in the book Planets, Stars, and Nebulae Studied with Photopolarimetry, edited by T. Gehrels in 1974, while other investigations were published i...

The application of the polarimetric technique to asteroid studies progressed significantly during the last decade. The most interesting results were the discovery of asteroids with peculiar polarimetric properties, new findings on wavelength dependence of polarization, and some improvements in the polarimetric method of albedo determination. We rev...

At least ten of low-albedo asteroids without nonlinear increasing of brightness down to subdegree phase angles were detected among outerbelt asteroids, Hildas and JupiterTrojans. It is possible that only the single scattering and shadowhiding mechanisms form their brightness behaviour. These asteroids have very low surface albedo and belong mainly...

We present new observational data for selected main-belt asteroids of different compositional types. The detailed magnitude-phase dependences including small phase angles (<1°) were obtained for these asteroids, namely: (10) Hygiea (down to the phase angle of 0.3°, C-type), (176) Iduna (0.2°, G-type), (214) Aschera (0.2°, E-type), (218) Bianca (0.3...

Regular photometric observations aimed for obtaining physical properties of near-Earth asteroids (NEA) are carried out within the Asteroid Search and Photometry Initiative (ASPIN) of the International Scientific Optical Network (ISON). At present, ISON project joins 35 observation facilities in 15 countries with 80 telescopes of different class. Ph...

The current concepts on the physical properties of the Jovian Trojans are reviewed in the paper. The distributions of rotation periods and light-curve amplitudes, the features of the phase dependencies of brightness, and the available data on the surface composition, density, diameters, and albedo of the Trojans are analyzed. The history of the dis...

CCD-photometry was performed for two Jupiter Trojan asteroids (911) Agamemnon and (4709) Ennomos for which the diameters were obtained from occultation events. New data on rotation periods, lightcurve amplitudes, color indices, magnitude–phase slopes, and absolute magnitudes were obtained for these asteroids. We have used the diameters from occulta...

We analyze here a wide sample of carbonaceous chondrites from historic falls (e.g. Allende, Cold Bokkeveld, Kainsaz, Leoville, Murchison, Murray and Orgueil), and from NASA Antarctic collection in order to get clues on the role of aqueous alteration in promoting the reflectance spectra diversity evidenced in the most primitive chondrite groups. We...

This paper presents the first results of CCD photometry of selected Hilda group asteroids. These observations are part of a program carried out in the Institute of Astronomy of the Kharkiv National University, that is aimed to receive the parameters of the rotation and the optical properties of asteroids from the resonant groups. The observations w...

Sunlight scattered by asteroidal surfaces is partially linearly polarized. The polarization depends on the physical properties of the particles (size, refractive index, structure), and varies with the geometry of observations (phase angle) and wavelength. The polarization phase curves of asteroids with a bell-shaped positive branch and a shallow ne...

New CCD-observations of asteroid (596) Scheila were carried out and magnitude-phase dependence was obtained after the collision impact with other object.

Polarimetric measurements of Centaurs (5145) Pholus, (10199) Chariklo, and (2060) Chiron were obtained in 2007 and 2008 with the FORS instrument of the 8m ESO Very Large Telescope. Each observing series consisted of one or two acquisition images, and from 8 to 16 images obtained with polarimetric optics in, setting the retarder plate at different p...

We interpret the polarimetric observations of transneptunian objects (TNOs) using a radiative-transfer coherent-backscattering model that utilizes a so-called phenomenological fundamental single scatterer (Muinonen and Videen, JQSRT, in press, 2012). The new modeling allows us to constrain the single-scattering albedo, phase function, and polarizat...

Context. We study the surface properties of transneptunian populations of Solar-system bodies. Aims. We investigate the surface characteristics of the dwarf planet (136472) Makemake and the resonant object (90482) Orcus. Methods. Using the FORS2 instrument of the ESO-VLT we have carried out linear polarisation measurements of Makemake and Orcus. Re...

The hydrated groups of carbonaceous chondrites (hereafter CCs) exhibit different degrees of aqueous alteration. Primary minerals were transformed in their parent bodies by the action of the water. Most of the water was probably accreted as ice or bounded in hydrated minerals. Moderate heating associated with residual radioactivity or collisional co...