Volume 27, Issue 1

In this paper, we address the question of how a central intermediate-mass black hole (IMBH) in a globular cluster (GC) affects dynamics, core collapse, and formation of the binary population. It is shown that the central IMBH forms a binary system that affects dynamics of stars in the cluster significantly. The presence of an intermediate-mass black hole with mass ≥ 1.0-1.7%of the total stellar mass in the cluster inhibits the formation of binary stars population.

Information on interstellar extinction and dust properties may be obtained from modern large photometric surveys data. Virtual Observatory facilities allow users to make a fast and correct cross-identification of objects from various surveys. It yields a multicolor photometry data on detected objects and makes it possible to estimate stellar parameters and calculate interstellar extinction. A 3D extinction map then can be constructed. The method was applied to 2MASS, SDSS, GALEX and UKIDSS surveys. Results for several high-latitude areas are obtained, compared with independent sources and discussed here.

Spiral patterns in some disc galaxies have two arms in the centre, and three or more arms on the periphery. The same result is also obtained in numerical simulations of stellar and gaseous discs.We argue that such patterns may occur due to fast cooling of the gas, resulting in formation of giant molecular clouds. The timescale of this process is 50 Myr, the factor of 10 shorter than of ordinary secular instability. The giant molecular clouds give rise to multiarm spirals through the mechanism of swing amplification.

We developed techniques for searching young unresolved star groupings (clusters, associations, and their complexes) and of estimating their physical parameters. Our study is based on spectroscopic, spectrophotometric, and UBVRI photometric observations of 19 spiral galaxies. In the studied galaxies, we found 1510 objects younger than 10 Myr and present their catalogue. Having combined photometric and spectroscopic data, we derived extinctions, chemical abundances, sizes, ages, and masses of these groupings. We discuss separately the specific cases, when the gas extinction does not agree with the interstellar one. We assume that this is due to spatial offset of Hii clouds with respect to the related stellar population.We developed a method to estimate age of stellar population of the studied complexes using their morphology and the relation with associated H emission region. In result we obtained the estimates of chemical abundances for 80, masses for 63, and ages for 57 young objects observed in seven galaxies.

The properties of unstable large-scale hydrodynamic (HD) modes of oscillations in the gaseous disk of a flat galaxy with a rotation curve having a velocity jump in the inner region of the disk are numerically investigated. It is shown that some of these modes can form a regular pseudo-ring, and others can generate a spiral structure in a model galactic disk, with the rotation curve that can approximate the observed rotation curves in nearby massive spiral galaxies (such as M31, M81). The characteristic time of formation of the regular structure turns out to be . (1 − 2) GY, the corotation is located in the region of the velocity jump (on the radius∼ 2 − 4 kpc). The properties of the generated densitywaves are determined by the parameters of the velocity jumpon the rotation curve (relative amplitude and steepness of the velocity profile decrease), as well as the temperature (velocity dispersion) of the gas in the disk. For the first time, it was investigated how the global HD modes and the spiral structures formed by them will change in the case of the presence of a jump in the profile of the equilibrium surface density. This model profile was set in the form of a slightly smeared falling density step. Main results were obtained for two-arm m = 2 azimuthal harmonic.

We have completed a survey of twenty-two ultraviolet-selected hot subdwarfs using the Fiber-fed Extended Range Optical Spectrograph (FEROS) and the 2.2-m telescope at La Silla. The sample includes apparently single objects as well as hot subdwarfs paired with a bright, unresolved companion. The sample was extracted from our GALEX catalogue of hot subdwarf stars. We identified three new short-period systems (P = 3.5 hours to 5 days) and determined the orbital parameters of a long-period (P = 62 d .66) sdO plus G III system. This particular system should evolve into a close double degenerate system following a second common envelope phase.We also conducted a chemical abundance study of the subdwarfs: Some objects show nitrogen and argon abundance excess with respect to oxygen. We present key results of this programme.

NY Virginis is an eclipsing binary system with a subdwarf B primary and an M type dwarf secondary. Recent studies (Qian et al. 2012; Lee et al. 2014) suggested the presence of two circumbinary planets with a few Jovian masses within the system. Lee et al. (2014) examined the orbital stabilities of the suggested planets, using the best-fit parameters derived from their eclipse timing variation analysis. They found that the outer companion should be ejected from the system in about 800 000 years. An observational report from Pulley et al. (2016) pointed out that the recent mideclipse times of the binary deviate significantly from the models suggested by Lee et al. (2014). In fact, variations in the orbital period of the system had already been recognized by many authors, but the parameters of these variations vary significantly as new data accumulate. Here, we analyze the eclipse timing variations of the NY Vir system, using new mid-eclipse times that we have obtained together with earlier published measurements in order to understand the nature of the system and constrain its parameters.

The bright sdO star HD127493 is known to be of mixed H/He composition and excellent archival spectra covering both optical and ultraviolet ranges are available. UV spectra play a key role as they give access to many chemical species that do not show spectral lines in the optical, such as iron and nickel. This encouraged the quantitative spectral analysis of this prototypical mixed H/He composition sdO star. We determined atmospheric parameters for HD127493 in addition to the abundance of C, N, O, Si, S, Fe, and Ni in the atmosphere using non-LTE model atmospheres calculated with TLUSTY/SYNSPEC. A comparison between the parallax distance measured by Hipparcos and the derived spectroscopic distance indicate that the derived atmospheric parameters are realistic. From our metal abundance analysis, we find a strong CNO signature and enrichment in iron and nickel.

The chemical composition of helium-rich hot subluminous O stars plays an important role to understand and model their formation history. We present a spectroscopic analysis of four He-sdO stars,CD-31° 4800, [CW83] 0904- 02, LSS 1274 and LS IV +10° 9. The analysis is based on archival optical and UV high-resolution spectra. We used Tlusty200/Synspec48 to compute line blanketed non-LTE model atmospheres and their corresponding synthetic spectra and derive the atmospheric parameters as well as the abundances of the most prominent elements. All stars have helium-dominated atmospheres with hardly any hydrogen and temperatures between 42000 K and 47000 K while their surface gravity spans between log g = 5.4 and 5.7. CD-31° 4800 shows an enrichment of nitrogen and the characteristic pattern of hydrogen burning via the CNO-cycle, while the rest of the elements have about the solar abundance. This points to the slow merger of two helium white dwarfs as the most likely origin for this system. The other three stars are enriched in carbon, nitrogen and neon while their intermediate mass element’s abundance scatters around the solar value. They were possibly formed in the deep mixing late hot flasher scenario.

Photometric surveys at optical, ultraviolet, and infrared wavelengths provide ever-growing datasets as major surveys proceed. Colour-colour diagrams are useful tools to identify classes of star and provide large samples. However, combining all photometric measurements of a star into a spectral energy distribution will allow quantitative analyses to be carried out. We demonstrate how to construct and exploit spectral energy distributions and colours for sublumious B (sdB) stars. The aim is to identify cool companions to hot subdwarfs and to determine atmospheric parameters of apparently single sdB stars as well as composite spectrum sdB binaries.We analyse two sdB stars with high-quality photometric data which serve as our benchmarks, the apparently single sdB HD205805 and the sdB + K5 binary PG 0749+658, briefly present preliminary results for the sample of 142 sdB binaries with known orbits, and discuss future prospects from ongoing all-sky optical space- (Gaia) and ground-based (e.g. SkyMapper) as well as NIR surveys.

We present a new asteroseismic modeling of the hot B subdwarf (sdB) pulsator PG 1219+534, based on a 3- month campaign with the Mont4K/Kuiper combination at Mt Bigelow (Arizona) and on updated atmospheric parameters from high S/N low and medium resolution spectroscopy. On the basis of the nine independent pulsation periods extracted from the photometric light curve, we carried out an astroseismic analysis by applying the forward modeling approach using our latest (third and fourth generation) sdB models. Atmospheric parameters (T eff = 34 258 ± 170 K, log g = 5.838 ± 0.030) were used as independent constraints, as well as partial mode identification based on observed multiplet structures we ascribed to stellar rotation. The optimal model found is remarkably consistent between various analyses with third and fourth generation of sdB models, and also with previously published analysis with second generation sdB models. It corresponds to a sdB with a canonical mass (0.46 ± 0.02 M ⊙ ), rather thin H-He envelope (log q(envl) = −3.75 ± 0.12), and close to He-burning exhaustion (X core (C + O) = 0.86 ± 0.05).We also investigate the internal rotation of the star.We find that PG 1219+534 rotates very slowly (P rot = 34.91 ± 0.84 days) and that solid-body rotation is reached at least down to ∼60% of the radius.

Identifying progenitor systems for the double-degenerate scenario is crucial to check the reliability of type Ia supernovae as cosmological standard candles. Santander-Garcia et al. (2015) claimed that Hen 2-428 has a doubledegenerate core whose combined mass significantly exceeds the Chandrasekhar limit. Together with the short orbital period (4.2 hours), the authors concluded that the system should merge within a Hubble time triggering a type Ia supernova event. Garcia-Berro et al. (2016) explored alternative scenarios to explain the observational evidence, as the high mass conclusion is highly unlikely within predictions from stellar evolution theory. They conclude that the evidence supporting the supernova progenitor status of the system is premature. Here we present the first quantitative spectral analysis of Hen 2-428which allows us to derive the effective temperatures, surface gravities and helium abundance of the two CSPNe based on state-of-the-art, non-LTE model atmospheres. These results provide constrains for further studies of this particularly interesting system.

HW Vir systems are rare eclipsing binary systems including a subdwarf B star (sdB) with a faint companion, mostly M-dwarfs. Up to now, 19 HW Vir systems have been published, three of them with substellar companions. We report the spectroscopic as well as photometric observation of the eclipsing sdB binary PTF1 J011339.09+225739.1 (PTF1 J0113) in a close (a=0.722 ± 0.023 R⊙), short period (P = 0.0933731(3)d) orbit. A quantitative spectral analysis of the sdB yields Te.=29280 ± 720 K, log(g)=5.77 ± 0.09 dex, and log(y)=−2.32 ± 0.12. The circular orbital velocity of the sdB of K1=74.2 ± 1.7 km s−1 is derived from the radial velocity curve. Except for the strong reflection effect, no other light contribution of the companion could be detected. The light curves - recorded with ULTRACAM - were analyzed using the Wilson-Devinney code. We find an inclination angle of i=79.88 ± 0.18∘. Because our first attempts to determine q failed, we calculated large grids of synthetic lightcurves for several mass ratios. Because of degeneracy, good solutions for different mass ratios were found - the one at q = 0.24 is consistent with the sdB’s canonical mass (MsdB = 0.47 M⊙). Accordingly, the mass of the companion is M2=0.112 ± 0.003 M⊙. The radii of the two components were also derived: RsdB=0.178 ± 0.006 R⊙ and R2 = 0.158 ± 0.009 R⊙. Thus, the results for the secondary are consistent with an M-dwarf as secondary

M5865 is the only so-far confirmed close binary found in the extreme horizontal branch (EHB) of a globular cluster. A detailed study has recently proposed that this object could be a close system (period P=1.61 days) comprising a EHB and a main-sequence star of mass M≈0.6 Mʘ. Such a system has never been found among hundreds of known EHB binaries in the field, and it results in a very interesting, unique object. In this contribution, we resume the previous literature results on M5865, we discuss the reasons of interest on it, and we present some very preliminary results obtained from new observations.

We present a status report of our spectroscopic analysis of subdwarf binaries consisting of a subdwarf and a F/G/K-type main-sequence companion. These systems selected from SDSS photometry show significant excess in the (infra-)red which can not be explained by interstellar reddening. Inspection of SDSS spectra revealed that most of them are composite spectrum sdB binaries. Once their spectra are disentangled, a detailed spectral analysis can be carried out. It reveals T eff , log g and the metal abundance of each individual star. The cool companion is of particular interest, because its spectrum reveals the original chemical composition of the binary.

An interesting opportunity offered by the detection of stellar oscillations is the possibility to infer the internal rotation rate of a star through the so-called rotational splittings. Such seismic measurements remained rather scarce for hot B subdwarf (sdB) stars until the advent of space observations with the Kepler spacecraft. Nowadays, however, a number of rotation measurements have become available, offering a glimpse on the global rotational properties of sdB stars. Here, we briefly discuss what asteroseismology starts to reveal on the rotation rate of these stars. We also make connections with the internal rotation of red-giant and white-dwarf stars. In particular, we show that the very slow rotation rates derived for single sdB stars, and their similarities with the dynamical properties of the cores of red-clump stars, strongly suggest that they evolved from red-giants rather than merger events.We also point out that no more angular momentum seems to be lost by stellar cores throughout the helium burning phase until the cooling white-dwarf stage, indicating that all the braking occurs before, most likely during red-giant branch evolution.

This paper reviews recent seismic findings from Kepler and K2 data. Using three years of short cadence Kepler (K1) data, it is possible to examine time evolution of pulsations in an unprecedented way. While K2 observations are shorter, only three months, they are important as they are finding more sdBV stars than K1 did. Most importantly, K2 is discovering more p−mode pulsators with coverage not possible to get from the ground.

This short review aims to clarify upon the origins of so-called Eddington-Barbier relationships, which relate the emergent specific intensity and the flux to the photospheric source function at specific optical depths. Here we discuss the assumptions behind the original derivation of Barbier (1943).We also point to the fact that Milne had already formulated these two relations in 1921.

The article represents the results of efficiency estimation for perspective observation facilities of near-Earth astronomy in terms of the AES (artificial Earth’s satellite) optical images obtaining and quality. A mathematical method for modeling optical images based on the induced virtual environment is proposed . A speckle interferometric image registration scheme and bispectral processing are reviewed. Upon modelling, the real speckle interferometric images of stars have been used as scattering functions; the AES orbits and geometry have been set in reliance on the real AES orbits and 3D-shapes. Additionally, photon and readout noises have been modelled. A large set of different variants of the AES orbits and 3D-shapes is reviewed.Anon-linear distortion problem is analyzed. The modelling has been performed under various atmosphere turbulence conditions (2”, 4”). The following characteristics have been estimated: number of frames to accumulate depending on the AES orbit and shape, noise intensity, type and parameters of bispectral processing, energy characteristics.

The new space project of M. V. Lomonosov Moscow State University on elaboration of multiple satellites for real time monitoring in the near-Earth space of radiation environment, natural (asteroids, meteoroids) and artificial (space debris) potentially dangerous objects, electromagnetic transients, such as cosmic gamma ray bursts, terrestrial gamma ray flashes, optical and ultraviolet bursts in the Earth atmosphere is presented. It is intended to install on the satellites the following instruments for space monitoring of dangerous objects and hazards: spectrometers of electrons and protons, complex of instruments for study of transient electromagnetic phenomena including gamma ray spectrometer, detectors of ultraviolet and optical emission and wide-field optical cameras. Successful implementation of the project for the first time in the world allows realization of a space system prototype for monitoring and preventing of space hazards for both ongoing and planned space missions, and also for aircraft flying in the upper atmosphere. There are also discussed results of experiments on-board Lomonosov in view of good experience of wide field camera use for monitor observations in space. These results formed the base of scientific program for the new project Universat- SOCRAT.

Chelyabinsk event of Feb 15, 2013 clearly demonstrated that decameter sizeNear EarthObjects (NEO) should be considered as hazardous ones. Another important lesson is that bodies approaching the Earth from day sky could not be discovered by any ground-based or near Earth space telescopes and the only way to detect these bodies reasonably well beforehand is to put the telescope(s) relatively far fromthe Earth.We proposed the project of space system SODA (System of Observation of Day-time Asteroids) for exhaustive detection of decameter (and larger) bodies approaching the Earth from the Sun direction (Chelyabinsk type meteoroids). The medium-size (30 cm) wide field telescopes are to be put into vicinity of L1 (Earth-Sun) point. Observations will be performed in barrier mode. Two options are considered: single spacecraft (SC) or pair of SCs. We describe major constituents and options of the project. The entire project could be implemented with off-shelf components and fits to low-cost project requirements. Special attention is paid to accuracy of orbit of the NEO. In a variant of two SCs capable to perform observation in triangulation mode accuracy of atmosphere entry point for Chelyabinsk-like body could be as high as few tens of kilometers.

Spacecrafts in geostationary orbit are subject to a complex set of disturbances that involve changes in orbital parameters. Corrections to the orbit are regularly carried out to keep the satellite at a given point of standing. The geostationary satellites must be moved to the disposal orbit after finishing their service life. Otherwise they begin to move towards the nearest stable point of libration and to make oscillatory movements in longitude, regularly approaching different satellites, which creates a threat of collision. The theory of motion for large space objects is well developed and their movement is predictable. However, small-sized fragments of space debris, are highly susceptible to difficult-to-predict non-gravitational disturbances. It is important to study the orbital motion of space objects that perform libration movements near 75∘E,where the majority of Russian working geostationary satellites are located. Optical measurements at observatories in Zvenigorod, at the Terskol peak and on Sanglokh Mount (Tajikistan) of some of the librational geosynchronous objects were performed. Results of the analysis of some of the geosynchronous small-sized fragments are given.

The meteoroid risk in circumterrestrial space is basically caused by 1-10 mm meteoroid bodies. Meteoroid particles of such dimensions cannot be registered by modern monitoring astronomical instruments. Observable are only meteor phenomena they cause. This work analyses the activity of main meteor showers over several years and assesses the danger from meteoroids with a size of more than 1 mm. The results of calculating the meteoroid risk during these showers’ maximum activity periods have shown that despite its low values it is sufficiently close to the maximum allowable risk. This already constitutes a recognizable danger, and such a danger needs to be taken into consideration.

ISON, being an open international project that collects and interprets data about space objects for scientific analysis and spacecraft operators, includes about 40 observational sites. An involvement of two Mexican sites participating in optical observations of geostationary and highly elliptical objects as a part of the ISON project is considered. A brief description of the facilities and their observation statistics are given. Prospects for the further development of sites for monitoring near-Earth objects in Mexico are presented, including data of astronomical observing conditions from field stations.

The purpose of this paper is to estimate to what temperatures and to what depth the outer layers of the cometary nuclei are heated for several dozen revolutions around the Sun, and what changes in the composition of the volatiles occur in this case. This is important because it is not clear how much the experimentally obtained results on the composition of cometary comes depend on how long the comet is in the current orbit. Our approach to this problem is based on using 3D model of the geometry and dynamics of a cometary nucleus that takes into account the diurnal rotation and orientation of the rotation axis relative to the Sun to simulate the irradiance to take value of temperature the surface of the nucleus and 1D thermal model of the porous ice-rock body. The results of the numerical simulation of heat propagation in the subsurface layers of some points the MA’AT region of the 67P core, obtained for the 20 orbital cycles (close to 130 years), are presented in this paper.

Low Earth orbits (LEO) are known as a region of high space activity and, consequently, space debris highest density. Launcher upper stages and defunct satellites are the largest space debris objects, whose collisions can result in still greater pollution, rendering further space missions in LEO impossible. Thus, space debris remediation is necessary, and the LEO region is a primary target of active debris removal (ADR) projects. However, ADR planning requires at least an approximate idea of the candidate objects’ attitude dynamics, which is one of the incentives for our study. This paper is mainly focused on modeling and simulating the attitude dynamics of defunct satellites. We consider a “boxwing” configuration satellite with an ellipsoid of inertia close to an oblate ellipsoid of revolution. The dynamical model takes into account the gravity-gradient torque, the torque due to the residual magnetic moment, and the torque due to eddy currents induced by the interaction of conductive materials with the geomagnetic field. A better understanding of the intermediate phase of the exponential deceleration and existing final regimes is achieved owing to a more accurate model of the eddy-current torque than in most prior research.We also show the importance of orbital precession, which contributes to the overall attitude motion evolution.

The paper continues to build upon the author’s previous research on fireballs fragmentation. A model of the sudden explosive destruction of the cosmic body at the height of the maximum flash is used. After the fragmentation, the kinetic energy of the moving particles of a meteoroid passes into the thermal energy of the gas volume inwhich their motion takes place. The temperature of a gas cloud calculated analytically using energy conservation lawand equations of physical theory of meteors. The mass distribution of fragments was taken from the literature. The high temperature of the gas in a cloud allows us to talk about the phenomenon of a "thermal explosion".

Perihelion distances of Marsden and Kracht group comets fall into the range 6RS < q < 12RS (the Meyer group comets also share the same perihelion interval). It is by several folds larger than the perihelion distance of the Kreutz group comets (q < 2RS). Average circulation period for comets of the Marsden group is P = 5.5 years and for the Kracht group is P =5.3 years. The Marsden and Kracht group comets share the same origin; as well as 96P (Machholz), object 196256 (2003 EH1), meteor showers the Daytime Arietids, Northern and Southern δ Aquariids, Quandrantids forming the Machholz interplanetary complex. This work offers computational movement simulation for comet-progenitor fragments. It is shown that the orbits of the representatives of the complex can be explained if the decay of the cometprogenitor for objects 96P and 196256 occurred ~9500 years ago. The following evolution direction has been demonstrated for the complex objects: progenitor comet - comet 96P - the Marsden group comets - the Kracht group comets - the Southern δ Aquariids. However, not all the complex objects will necessarily pass through every stage of the above as it can be preceded by the total disintegration of the object.

In this paper we retrace the course of near-Earth astronomy from its beginnings.We emphasize the problem of space debris, which has arisen somewhat unexpectedly, and only keeps on growing and growing.We also cast a glance over the conferences, held by our Institute biennially.

The study of near-Earth space includes the detection and investigation of an increasing number of space debris objects by ground-based optical telescopes. There is no natural cleansing of space in the geostationary region. The telescope Zeiss-2000 with a two-meter aperture of the Terskol observatory is the largest optical instrument regularly used for space debris investigations. One of the main purposes in «Astronomy in the Elbrus region» international program’s boundaries is the detection and characterization of small fragments of debris,which are invisible for smaller telescopes. During observations on photometric nights we usually detect 4-5 unknown fragments of 17-21 st star magnitude. In this article, we present orbital parameters and physical characteristics of several small-sized fragments of the space debris detected at the Terskol observatory in 2016-2017.

An artificial neural network is described for classification of meteor trails into the distinct overdense, intermediate and underdense trail categories. The neural network was trained and on model data obtained using the “KAMET” program and tested on real data. The best result of classification success rate of 95% without according to the heights of the formation of meteor trails. Results of classification with according to the heights of the formation of meteor trails are 82% - 91%.

We re-processed spectroscopic echelle data on 1999 S4 (LINIER), a catastrophically disintegrated comet, and 2001 Q4 (NEAT) obtained at not quite favorable circumstances. Photometric conditions at the observations were good but measurements of the spectra for the first one were performed at a large zenith distance and the second - with a relatively low spectral resolution. Nevertheless, we succeeded in detection and identification of fluorescent emission lines of 9 polycyclic aromatic hydrocarbons and simpler molecules in the spectra of both comets. Our results are in accordance with those of other authors and substantiate present notions about origin of the comets.

We investigate the precision within which a simulated dark matter halo mass function can be rescaled to a different set of cosmological parameters. Our tests show that the accuracy almost linearly depends on the difference of the cosmological parameters and amounts to few percent in the case of WMAP5 and PLANCK parameters. The rescaling thus allows us to obtain a mass function with better precision than the one given by the Sheth-Mo-Tormen approximation and even more modern fits currently used in the literature.

This work seeks to summarize some special aspects of a type of exoplanets known as super-Earths (SE), and the direct influence of these aspects in their habitability. Physical processes like the internal thermal evolution and the generation of a protective Planetary Magnetic Field (PMF) are directly related with habitability. Other aspects such as rotation and the formation of a solid core are fundamental when analyzing the possibilities that a SE would have to be habitable. This work analyzes the fundamental theoretical aspects on which the models of thermal evolution and the scaling laws of the planetary dynamos are based. These theoretical aspects allow to develop models of the magnetic evolution of the planets and the role played by the PMF in the protection of the atmosphere and the habitability of the planet.

An ancient Egyptian Calendar of Lucky and Unlucky Days, the Cairo Calendar (CC), assigns luck with the period of 2.850 days. Previous astronomical, astrophysical and statistical analyses of CC support the idea that this was the period of the eclipsing binary Algol three millennia ago. However, next to nothing is known about who recorded Algol’s period into CC and especially how. Here, we show that the ancient Egyptian scribes had the possible means and the motives for such astronomical observations. Their principles of describing celestial phenomena as activity of gods reveal why Algol received the title of Horus.

The model of the galaxy is considered as a structure of the baryonic matter embedded into the hot dark matter. The dark matter is supposed to come into being from the decaying matter after the epoch of structure formation. The galaxy is divided into two regions. In the inner region, the baryonic matter predominates over the hot dark matter while in the outer region, the hot dark matter predominates over the baryonic matter. The motion of the test particle is bounded in the inner region (elliptic orbit) and unbounded in the outer region (parabolic orbit). Observational constraints on the proposed model are considered from the rotation curves of the galaxies: Milky Way, M33, NGC 2366 and IC 2574.

The intersections between a spherical shell and the faces of Voronoi polyhedrons are numerically evaluated. The nodes of these intersections are the points that share the same distances from three nuclei. The nodes are assumed to be the places where we will find clusters of galaxies. The cosmological environment is given by the coupling between the number of galaxies as function of the redshift and the LCDM cosmology.

Cometary bodies are acknowledged to contain some of the most pristine matter in the Solar System, including ices and minerals. Certain number of previously unidentified spectral emission features detected in comets can be explained as emission by hydrocarbon molecules enclosed in a Shpolskii matrix and forming frozen hydrocarbon particles. UV-induced photoluminescence spectra of several self-organized molecules exhibit emission lines coincident with unidentified cometary lines, and open the possibility of the presence of this complex organic as components of the pristine organic inventory of comets. Complex organic was detected also in three satellites of Saturn. We describe in this paper results of our investigation of complex organic of the small bodies and present new approaches and hypotheses.