... Future seminars . P a s t seminars . ... Ejection of material from a comet after its collision with a smaller body, probabilities of collisions of migrating small bodies and dust particles with planets, and formation of small body binaries " . ... The probabilities of collisions of different small bodies (asteroids, comets, and trans-Neptunian objects) and dust particles of different sizes produced by these bodies with all planets are considered for dynamical lifetimes of bodies and particles. ...

The Extended Soft Approximation for Spherical Particles A.Y. Perelman St.Petersburg State Forest Technical Academy and N.V. Voshchinnikov Astronomy Department and Sobolev Astronomical Institute, St.Petersburg University Abstract The soft approximation (SA) gives the possibility to obtain the different optical characteristics of particles from the common point of view [1]. As for the Mie theory, they are expressed in terms of the scattering coefficients $a_n$ and $b_n$. ...

... The analysis shows, that asteroid ­ rubble pile loses its fast fragments in no time but the retaining fragments forms a compact structure immersed in dust ­ gas atmosphere, created by interaction of interplanetary medium with dispersed product of collisional evolution of asteroid. By interaction of an asteroid ­ rubble pile with interplanetary medium structures asteroid can increase its brightness on account of blowed up dust simulating phenomenon of distant comet's brightening. ...

... The distributions of orbits eccenttricities and of angular momenta for the halo stars and the old disk population are considered. The distributions have gaps separating the halo from the disk and dividing the halo population into three groups. ... Рассмотрены распределения звезд гало и старого населения диска по величине эксцентриситета орбит и угового момента. Распределения имеют провалы, отделяющие гало от диска и делящие населения гало на три группы. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... The rates of type Ia supernovae from double degenerate mergers channel in different star formation models (left panel), and the rate contribution function to the present-day ( t disc = 10Gyr) supernovae rates in the thin disc (right panel). ... We have compared the impact of different star-formation models on the rates and numbers of DDs and on the rates of type Ia (SNIa) and core-collapse supernovae (ccSN). ...

Report “Laboratory zero-baseline interferometer tests” (ZBT) was prepared and issued in ASC (35 pages including 17 figures and diagrams in Russian language). ... The Ground-Space radio interferometer (OVLBI) Radioastron includes several space and ground-based segments which are designed and manufactured by different countries and organizations. ... ZBI tests (for OVLBI) were implemented in Russia firstly. The tests were implemented by joint team of ASC, JPL and NRAO in 1999. ...

CORRELATIONS OF MEDIUM. SCALAR F I E L D I N THE STOCHASTIC A. Z. Bolginov, Ioffe Physical-Technical Institute 194021, Politekhnicheskaya, 26, Leningrad USSR N. A. Silant'ev Pulkovo Astronomical Observatory 196140, Leningrad USSR ABSTRACT: Correlations between the scalar field values (temperature, particle number etc.) in two space - time points in the turbulent medium are considered. Explicit analytical fore of correlators is obtained. ...

... Space Science Education . ... Particle detectors networks for the Fundamental Physics, Space Weather and Education . ... A network of middle to low latitude particle detectors called SEVAN (Space Environmental Viewing and Analysis Network) is planned in the framework of the International Heliophysical Year (IHY), to improve fundamental research of the space weather conditions and provide possibilities to perform short and long-term forecasts of the dangerous consequences of the space storms. ...

... We have developed an integrated system that performs astronomical observations in Near Infrared bands operating two-dimensional instruments at the Italian National Infrared Facility's ARNICA and LONGSP . ... The user interface is organized as widget-based X11 client. ... 1993; Di Giacomo et al. 1993). ... Moreover, if the interprocess communication interface includes support for networking, the software immediately becomes network distributed software. ... DESQview/X User Guide 1993, Quarterdeck . ...

... We present J(1.25 $\mic$), H(1.65 $\mic$), K(2.2 $\mic$), H$_2$(2.125 $\mic$) an d 11.2$\mic$ infrared images at sub-arcsec resolution of an area centered around the star forming region G~35.20--1.74. In J, H and K a cluster of early type stellar sources with infrared excess clearly stands out with respect to the background distribution and is associated with a diffuse K emission around an UC HII region (which is the brightest source at K). ... At 11.2$\mic$ six components are detected. ...

... All the galaxies are divided into 4 groups depending on the environment type; every subsample contains more than 10 galaxies. ... An effect of environments is seen both for the nuclei and for the bulges: if we consider the clusters (Virgo and Ursa Ma jor) and group centers as dense environments and the field and group periphery as sparse environments, then in the dense environments the stellar populations of S0s are in average older by 4­5 Gyr than in the sparse ones. ...

... The Chandra COSMOS Survey 2. ... Evidence that Compton-thick and Compton-thin obscured AGN have two physically different origins on different scales are presented and the implications for surveys and AGN evolution are discussed. oral . Monday: Type I and II AGN, Absorption, XBONGs, Tuesday: AGN correlation functions, LSS, environments . ... Monday: X-ray luminosity functions and evolution, Tuesday: AGN correlation functions, LSS, environments . ...