Conference Timetable
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08:30 - 09:00 Registration...
09:00 - 10:00 Invited talks (2 x 30 min.):
- Erik Hog (Niels Bohr Institute, Copenhagen, Denmark)
Absolute astrometry in the next 50 years Abstract
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Erik Hog. "Absolute astrometry in the next 50 years"
With Gaia in orbit since December 2013 it is time to look at the
future of fundamental astrometry and a time frame of 50 years is
needed in this matter. Eleven science issues for a Gaia successor
mission in twenty years are presented and in this context the
possibilities for absolute astrometry with mas or sub-mas
accuracies are discussed. In brief, the two Gaia-like missions
would provide an astrometric foundation for all branches of
astronomy from the solar system and stellar systems to compact
galaxies, quasars and dark matter (DM) by data which cannot be
surpassed the next 50 years.
The presentation is based on:
The astrometric foundation of astrophysics
Absolute astrometry in the next 50 years
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Zhengxin Li. "New role of ground astrometry in space era"
Space techniques have replaced most of the functions which were
once uniquely executed by ground based astrometry techniques. Is
there any future for the ground based astrometry technique now?
During the 21st General Assembly of the International
Astronomical Union (IAU), a resolution was passed by Commission
19 in which it was stated that 'astrometric observations provide
a unique set of data sensitive to variations in the deflection of
the vertical. . .'. This is the only special case observation
that must be performed by ground based astronometry.
This is an important observation and must be preserved, it's
future depends on the following:
[1] Is the magnitude of the variations in the deflection of the
vertical meaningful enough to be determined in practice?
[2] If it is so, what is the cause of these variations? Can we
determine them by astrometry techniques?
[3] If the variations are significant, then what is the usage of
these determined variations in Sciences and Technologies?
The paper summarize the works have been done in China. More and
more evidence is showing that astrometry may play an role in
providing observations of the variations in the deflection of the
vertical which is related to the mass changing underground, for
example, the mass migration before and after an earthquake in
northern China. Thus the techniques may be useful in predicting
earthquakes, as well as monitoring underground water and other
phenomena which are essential for the health and safety of
millions people. In the past astronomers have looked either into
the sky or on the ground's surface. Now might be the time to look
into the ground and this technique may find a useful purpose and
future.
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10:00 - 11:00 Invited talks (3 x 20 min.):
- Irina Belskaya (Inst. of Astr., Kharkiv Nat. Univ.)
From Asteroids to Transneptunian Objects: an Overview
of Physical Properties. Abstract
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Irina Belskaya. "From Asteroids to Transneptunian Objects:
an Overview of Physical Properties"
Asteroids and transneptunian objects (TNOs), that form two belts
of small bodies in the inner and outer parts of the Solar system,
are believed to contain fossil remnants from its early stage.
Their investigation has a key value for understanding the
formation and evolution of the Solar System. Study of small Solar
system bodies has achieved significant advances during last
decade. Observational data have increased exponentially thanks to
large ground-based telescopes and space missions. An overview of
physical properties will be given for various dynamical groups of
objects, including Near-Earth objects, main belt asteroids,
Trojans, Centaurs, and transneptunian objects.
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- Yuriy Voitenko (Inst. for Space Aeronomy, Belgium)
Solar wind turbulence from MHD to kinetic scales.Abstract
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Yuriy Voitenko. "Solar wind turbulence from MHD to kinetic scales"
Alfven waves and turbulence provide an important source for
energy transport and release in solar-terrestrial plasmas. An
intrinsic property of nonlinear interactions among MHD Alfvenic
fluctuations is an anisotropic spectral transfer of energy toward
progressively smaller wavelengths perpendicular to the mean
magnetic field. High-resolution Cluster observations of the solar
wind turbulence have revealed that the turbulent cascade is not
terminated at the so-called high-frequency spectral break, but
extends further into the kinetic-scale range. The resulting
turbulence at small kinetic scales is dominated by highly oblique
kinetic Alfven waves (KAWs).
We develop the theory of the turbulence transition from MHD to
kinetic scales. Nonlinear interactions among KAWs produce spectra
that are significantly steeper than the Kolmogorov-like MHD
turbulent spectra with the slope -5/3. In the asymptotic kinetic
range, well below the ion gyroradius scale, the spectral index of
the strong turbulence is -7/3. However, in the intermediate range
between the asymptotic MHD and kinetic ranges we found even
steeper spectra with the slope -3 formed by weakly dispersive
KAWs [Voitenko and De Keyser, 2011].
The resulting double-kink spectral pattern is often seen in the
turbulent spectra measured by Cluster. The intermediate-range
KAWs interact with particles efficiently and give rise to various
non-thermal features in the particle velocity distributions. In
particular, the proton (and heavier ions) distributions are
affected by KAWs and deviate significantly from the Maxwellian
ones in the velocity range covered by the KAW phase velocities
[Voitenko and Pierrard, 2013]. Proton beams, extended anti-
sunward tails, and several other non-thermal features observed in
the solar wind are thus a natural consequence of the kinetic-
scale Alfvenic turbulence.
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- Sergey Marchenko (Sci. Systems and Applications. & Goddard SFC, NASA)
Sun as a Star: Spectral Variability in the UV-VIS Range.Abstract
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Sergey Marchenko. "Sun as a Star: Spectral Variability in the UV-VIS Range"
The excellent stability of the Ozone Monitoring Instrument on
board the Aura satellite allows us to reveal and monitor both
short-term (solar rotation) and long-term (solar cycle) changes
of the spectral solar irradiance (SSI) between 265-500 nm during
the current Cycle 24, from 2009 to the present. SSI variability
in the relatively line-free regions amounts to ~0.6% +/- 0.2%
around 265 nm, gradually diminishing to 0.15% +/- 0.20% at 500
nm. This gradual decline of variability is also followed by all
prominent spectral lines and blends, with a remarkable exception
of upper-Balmer lines.
Besides the spectral features with known presence of a strong
chromospheric component (Mg II, Ca II), the most involved species
include Fe I blends and all prominent CH, NH and CN molecular
bands. We demonstrate that in the 265-500 nm range the magnitudes
and spectral dependencies of short-term (rotational) and long-
term (solar cycle) SSI changes are generally consistent, with
only a hint of wavelength-dependent deviations. Comparison of the
extensive data sets shows good repeatability of the SSI
variability patterns in the Solar Cycles 21-24.
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11:00 - 11:30 Short coffee / tee break + cookies
11:30 - 13:30 Invited talks (4 x 30 min.):
- Leonid Ksanfomality (Space Res. Inst. RAS, Russia)
Planets of Solar System and Exoplanets: from Venus
to Oceanic Planets. Abstract
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Planetans - Oceanic Planets
L.V.Ksanfomality. Space Research Institute, Moscow
leksanf@gmail.com
The analysis of experimental data obtained in studies of extrasolar low-mass
planets indicates that there is one more class of celestial bodies-planetans-oceanic
planets with global water oceans that have high, but subcritical, temperatures.
A convenient method of analysis is using of entropy-entalphy diagram. The
atmospheres of planetans should be composed mainly of water vapor under high pressure.
The number of detected planetans will grow as new exoplanets with masses of 1-5 Earth
masses are discovered. The properties of some low-mass objects that were determined
using different methods, including Kepler-11, Kepler-22, GJ 1214b, and Gl 581g, differ
appreciably.
The exoplanet GJ 1214b cannot be a planetan. On the contrary, properties of
a planetan may have the exoplanet GL 581g, if it spherical albedo reaches a value
of 0.86 (like of some of Jupiter and Saturn satellites). The radiation of the star
Gl 581 itself is mainly concentrated in the IR range, making the photolysis of water
vapor in the upper atmospheric layers of Gl 581g inefficient. For this reason, the
exoplanet Gl 581g does not loss appreciable water on a cosmogonic timescale.
On the contrary, it is shown that the identification of GJ 1214b with the model of
a planetans (as an object with low mean density) seems to be erroneous. An alternative
model of the structure of GJ 1214b suggests the existence of a silicate-metal core
with a density of 13 g/cm3 and a radius of 5000 km and a middle layer with a density of
9 g/cm3 and a radius of 10000 km. The middle layer includes a mixture of volatile
substances, mostly water, with traces of methane and ammonia. Its dense atmosphere
corresponds to the observed diameter of the exoplanet, extending to 7500 km. A possible
habitability of planetans is considered.
References:
Ksanfomality L.V. 2014 Solar System Research, 48 (1), 79
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- Evgeny Polyachenko (Inst. of Astr., RAS, Russia)
Theories of spiral structure in galaxies. Abstract
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Evgeny Polyachenko. "Theories of spiral structure in galaxies"
In the talk we trace the onset and formation of the theory of
spiral structure of galaxies from the classical works of Jeans
and Lindblad to the present day. The main part of the report is
devoted to the confrontation of quasi-stationary density waves
approach to approach utilizing transient spirals. Besides we
consider alternative theories of spiral structure formation such
as MHD theory, Fridman hydrodynamical conjecture and shallow
water experiments, and various theories of bar formation in SB-
galaxies including fast and slow bars.
We consider the problem of constructing a dynamic model and the
current understanding of the Milky Way spiral structure, as well
as the expected results due to the launch of new space
telescopes.
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- Jacek Krelowski (Center for Astr., Nicholas Coper. Univ., Torun, Poland)
Kinematics of the outer parts of the galactic disc -
the role of possible Dark Matter. Abstract
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Jacek Krelowski. "Kinematics of the outer parts of the
galactic disc - the role of possible Dark Matter"
The mysterious Dark Matter is currently being called the Saint
Graal of science. The estimates of its mass give the values many
times higher than that of the "traditional" baryonic matter.
However, all attempts to detect this form of matter directly (not
via its gravity) failed. One of the serious problem follows the
fact that the crucial evidence of the Dark Matter follows flat
rotation curves of spiral galaxies.
While building such a curve for our Milky Way, the main source of
uncertainty follows the distance measurements. Basing on the huge
collection of echelle spectra of OB stars we demonstrated that
distances to the thin disc objects (OB stars, interstellar clouds
being revealed by CaII absorptions) can be reliably estimated
using intensities of interstellar CaII H and K lines. The same
lines allow also to measure Doppler shifts to the most distant
clouds along any sightline with the precision much higher than in
the case of stellar spectra as the latter are influenced by fast
rotation and binarity of many OB stars.
The talk will demonstrate that even the existing data create
serious doubts as to the existence of Dark Matter: the rotation
curves of young, disk population objects clearly follow keplerian
rather than flat rotation curve of the Milky Way. The result is
based on a statistically significant sample of objects, situated
in the most interesting directions in the galactic disk, namely l
= 135 deg., l = 180 deg and l = 225 deg. The first two ones are
available from the Terskol Observatory. Our result, creating
serious doubts on whether our Galaxy is embedded in the dark
halo, is based mostly on the spectra from this Observatory.
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- Igor Karachentsev (SAO RAS, Russia)
Star Formation rate in the local volume galaxies. Abstract
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Igor Karachentsev. "Star Formation rate in the local volume galaxies"
A distance-limited sample of 869 objects from the Updated Nearby
Galaxy Catalog is used to characterize the star formation status
of the Local Volume population. I present estimates of star
formation rate (SFR) for 802 galaxies within 11 Mpc, derived from
the H-alfa imaging survey with the 6-m BTA telescope and the far-
ultraviolet survey with GALEX. I briefly discuss some basic
scaling relations between the SFRs and galaxy luminosity,
morphology, HI-mass, surface brightness, as well as environment.
About 3/4 of our sample consist of dwarf galaxies. It is noted
that the specific SFR of nearly all luminous and dwarf galaxies
does not exceed the maximum value: log(SFR/M*)= -0.4 [Gy-1].
Most spirals and blue dwarfs have enough amount of gas to support
their observed SFR over the next Hubble term. Only a 5% - fraction
of {BCD, Im, Ir} - galaxies proceed in a mode of vigorous
starburst activity. In general, the star formation history of the
late-type galaxies is mainly driven by their internal processes.
The present SFRs of {E, S0, dSph} - galaxies are typically ~1/100
of their former activity.
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13:30 - 14:00 Lunch break + snacks + coffee / tee + cookies
14:00 - 16:00 MAO report. NASU VFA.
16:00 - 18:00 Invited dinner.
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In a case of any problem with your registration, please, send the e-mail
(or contact with any other way) to the LOC members:
E-mail: mao-2014-loc@mao.kiev.ua
Phone: 380 (44) 526-31-10
Fax: 380 (44) 526-21-47
Ludmila Pakuliak or Marina Ishchenko.
Pakuliak Ludmila pakuliak@mao.kiev.ua
Marina Ischenko marina@mao.kiev.ua
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