JOSÉ LUIS BALLESTER
Departamento de Física, Universitat de les Illes Balears
Abstract. The solar corona
is the outer layer of the solar atmosphere and is
structured by the coronal magnetic field.
During the last thirty years, space missions have provided us with a lot of information about the physical conditions and
structures of the solar corona, however, several important phenomena still remain without explanation. Among them,
we could mention the coronal heating problem, and the onset and development of coronal mass ejections.
Key words: Sun – solar corona – active regions − magnetic field.
ASTRONET: PLANNING FOR EUROPEAN ASTRONOMY
Niels Bohr Institute, Copenhagen University
Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark
Abstract. ASTRONET is a
European project financed by the European Commission for 4 years and
of several European countries. Its aim is to establish a comprehensive, long-term planning process for all of European
stronomy – at all wavelengths, from the ground and from space, and for all of
and the planning for infrastructures is ongoing.
Key words: European astronomy – Science Vision – infrastructures.
CHEMICAL AND DYNAMICAL EVOLUTION OF THE GALACTIC DISK
Niels Bohr Institute
Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark
Abstract. We consider the
Milky Way Galaxy a typical spiral galaxy. Stars
from its entire history are available for study.
Complete data for 14,000 long-lived stars allow us to study the chemical and dynamical evolution of the Galactic disk.
We find that there is a large scatter in metallicities at all ages and that the velocity dispersion increases throughout the history
of the Milky Way. These findings are challenges for the standard evolutionary models and more detailed models are needed.
Key words: Galactic Disk – age determination – age-metallicity relation – disk heating.
THE EVOLUTION OF GALAXIES
II 1401, Praha 4
Abstract. The evolution of
galaxies results from a combination of internal
and external processes. The star formation is an
internal process transforming cold and dense cores of molecular clouds to stars. It may be triggered internally by expanding
shells, or externally, e.g., by galaxy collisions. The gas accretion and galaxy merging events are external contributors to galaxy
evolution. They compete with another internal process of galaxy evolution, which is the secular evolution redistributing the mass
and angular momentum inside of galaxies as a consequence of bar and spiral arms formation. As a nearby example of gas
accretion we mention the interacting system Milky Way − Large and Small Magellanic Clouds. Stripping of ISM in galaxy
clusters is reviewed as another example of interaction of galaxies with their environment.
Key words: ISM: structure − Stars: formation − Galaxies: evolution – Galaxies: star clusters – Galaxies: Magellanic Clouds – Galaxies: interactions -- Galaxies: clusters.
CHROMOSPHERICALLY ACTIVE SINGLE AND BINARY STARS − SPOTS: THE SOLAR-STELLAR CONNECTION
of Astrophysics-Astronomy and
Mechanics, Faculty of Physics,
Abstract. The active single as
well as binary stars are examined in this short review. In particular,
methods used to study their spot activity
from photometric and spectroscopic data are presented. The up-to-now achieved results are mentioned, and a comparison to the Sun is given, too.
Key words: active variable stars – active binary systems – sunspots – spots data analysis.
MAGNETIC SUPPORT OF PROMINENCES
Observatoire de Paris, Section Meudon LESIA,
92195 Meudon, France
Abstract. Prominences are
intriguing to solar physicists since more than a
century. Many problems concern the support of the cold and
dense plasma of prominences (104 K) embedded in the hundred times diluted and hot corona (106 K). I will review the different possible
models concerning such structures.
Key words: solar physics – Sun prominences – MHD.
SOLAR ACTIVE REGIONS
JAN OLOF STENFLO
Abstract. Practically, all
variability in the Universe, on short or
intermediate time scales, is caused by magnetic fields. Dynamo
in stellar interiors generate magnetic fields that are brought up to the surface by buoyancy forces and emerge in the photosphere as bipolar
magnetic regions. The large-scale bipolar regions on the Sun, which emerge at low heliographic latitudes, are what we normally call “solar
active regions” with sunspots, faculae, and flares, above which a dynamic and complex system of closed magnetic loops in the corona forms.
There is however a continuous scale spectrum of bipolar regions, spanning from the large scales to the smallest scales that we can resolve.
While we can observe reasonably well how magnetic flux emerges in the solar atmosphere, we know almost nothing about the processes by
which flux is removed. The flux removal rate must balance the flux emergence rate, otherwise the solar atmosphere would very quickly get
choked by the accumulated magnetic fields, but we do not know how this is done. This is a central problem with implications for many areas
of contemporary astrophysics.
Key words: Sun – magnetic fields – dynamo processes.
STUDY OF THE SEISMICALLY ACTIVE FLARE OF JULY 16, 2004
DIANA BeŞliu-Ionescu 1, 2, ALINA-CĂTĂLINA Donea 1, PAUL S. CALLY 1,
CHARLES LINDSEY 3
1 Centre for Stellar and Planetary Astrophysics
of Mathematical Sciences,
Clayton 3800, Australia
E-mail: firstname.lastname@example.org, email@example.com, firstname.lastname@example.org
Institute of the
Str. Cuţitul de Argint 5, 040557, Bucharest, Romania
NorthWest Research Associates, Inc.
have proven to be the most powerful events occurring at the solar
are triggered by the impulsive
flares produced in the corona, just above the acoustically active regions. Not every impulsive flare produces seismic waves emanating
from the highly depressed photosphere, just beneath the flare.
So far, we have identified a few
mechanisms which can deliver acoustic energy into the photosphere: (1)
suddenly heating the photosphere; (2) a strong shock-like compression wave propagating downwards into the chromosphere; (3) relativistic
particles delivering directly the energy and momentum into the photosphere; (4) probably the magnetic tension at the feet of the loops.
In order to discriminate which of
these is the most efficient or dominated during a particular
active flare, we have analyzed
the coronal and chromospheric emission of the regions just above the seismic source. We have performed a multiwavelength analysis of the
active region 10649 that hosted the acoustically active solar flare of
layers of the Sun, from the photosphere to the corona, suggests that high-energy particles travel through the coronal layers from the reconnection
site, hit the solar chromosphere warming it up, which then, responds by sending further into the photosphere sufficient energy (carried either by
the shock wave or by the Balmer and Paschen radiation) to produce a seismic event.
Key words: solar flares – sunquakes – Hα observations.
OF THE ATMOSPHERE
COSMIC RAYS. EXPERIMENTAL
OF THE “UNIVERSITETSKY-TATIANA” SATELLITE
GALI GARIPOV, BORIS KHRENOV, PAVEL KLIMOV
Skobeltsyn Institute of Nuclear Physics
Gory 1, 119992
Abstract. Detector on board
radiation from January 2005 to March 2007. The data on various kind of UV-radiation (scattered moonlight, aurora lights, and transient
luminous events) are presented. They are discussed in the context of future observation by space-based detectors of UV fluorescence
tracks produced in the atmosphere by ultra-high energy cosmic rays.
Key words: night atmospheric UV radiation – transient luminous events – ultra-high energy cosmic rays.
ENVIRONMENTAL EFFECTS ON GALAXIES IN CLUSTERS
Institute of the
Boční II 1401,
Abstract. Using the
N-body/SPH code GADGET adapted for interactions of two
gaseous phases, we study the influence of ram
pressure stripping on spiral galaxies in galaxy clusters. Galaxies on highly radial trajectories cross in the cluster center the density peak
of the intracluster medium (ICM) and experiences a time-varying wind. Density of the ICM and orbital velocity of the galaxy determine
effects of the ram pressure. Depending on the duration and intensity of the interaction, different amounts of interstellar material (ISM)
are found to be stripped from galaxies. The presence of the ISM in the galaxies is crucial for their star formation activity.
Key words: galaxy clusters – galaxy interaction – interstellar material.
SOLAR OBSERVATIONS FROM
TATJANA JAKŠIĆ 1, MIODRAG DAČIĆ 2, ISTVAN VINCE 2
Trg 16, 11000
Volgina 7, 11160 Belgrade, Serbia
Abstract. From 1974
up to 1994, observations of stars, and Sun, Mercury and Venus, were
daylight with the
of the Astronomical Observatory of Belgrade. The principal goal of these observations was to correct the positions of the vernal equinox
point and of the celestial equator plane. Numerous observations of upper and lower, as well as right and left Solar disk edges, enabled the
determination of the solar diameter variations as function of time. This allowed the investigation of the correlation of the considered variations
with the cycle of solar activity.
Key words: astrometry – vernal equinox – equator plane − solar diameter variations.
THE PERIODIC COMETS
29P/SCHWASSMANN-WACHMANN AND 1P/HALLEY
Famil Mustafa, Ayyub Guliyev, Elchin Babayev, Peter Shustarev
Shamakhy Astrophysical Observatory named after N. Tusi
Istiglaliyyat Street, AZ-1001,
influence of solar activity on changes of brightness of two
periodic comets (29P/Schwassmann-Wachmann and 1P/Halley)
is investigated. The brightness changes of 1P/Halley were studied on the basis of about 5900 estimations of brightness data obtained along
the period 1981−1989 and covering distances from 0.6 AU up to 9 AU. The brightness curve of 29P/Schwassmann-Wachmann was a
result of about 1300 estimations for the period 1976−2005. Spectral, correlation and cross-correlation analyses of both variations in solar
activity (different mechanisms) and changes of brightness of the investigated comets showed a presence of similar changes for the same
considered time span. Some well-known periodicities in solar activity variations were also revealed in periodical changes of comet brightness.
It is concluded that interrelations between solar activity variations and brightness changes of studied comets are significant. The telescope
apertures are also to be considered in calculations.
Key words: solar activity – periodic comets – brightness changes – telescope aperture.
AND SHAPE OF
THE SOLAR CORONA
THE TOTAL SOLAR
MYKOLA PISHKALO, IEVGENIIA SADOVENKO
Faculty of Physics, Department of Astronomy and Space Physics
Glushkove ave., Kyiv-127,
of the solar corona during the total solar eclipse of
March 29, 2006
determined. The flattening index e = a + b was found to be about 0.17. Main coronal structural features were found to be northern
and southern polar ray systems over polar coronal holes and six streamers of different brightness, located in middle and low heliographic
latitudes. Detailed coronal structure was analyzed. It was found that all coronal structural features had their counterparts on
photosphere-chromosphere level, at the limb or near it.
Key words: Sun – solar corona – structure – flattening index.
ADRIAN SABIN POPESCU
Institute of the
Str. Cuţitul de Argint 5, 040557 Bucharest, Romania
interpret the D.E.U.S. (Dimension
Embedded in Unified Symmetry) objects embedded in the catenoid of a
D.E.U.S. object as Stephani Universes. In this assumption, we check for the validity of the Gibbs-Duhem equation, one of the four
conditions needed in order that the fluid to evolve in local thermal equilibrium.
Key words: spacetime topology − multiverse − thermodynamic processes.
Interplanetary magnetic field asymmetry near Earth’S orbit
Astronomy and Space Physics Department
Abstract. The interplanetary
magnetic field (IMF) is strongly related to very various phenomena of
wind. The direction and
magnitude of IMF change continuously and significantly. In this paper we investigate the long-time variation of magnitude and direction
of the IMF vector. The IMF near the Earth was studied using the National Space Science Data Center OMNI database. We obtained
an asymmetry in the distribution of the IMF direction: the northern field is stronger than the southern one. We also analyze IMF distribution
during the different phases of the solar cycle and solar wind parameters.
Key words: interplanetary magnetic field – solar wind − heliosphere.
(LLBL): STRUCTURE, DYNAMICS,
AND MAGNETOSHEATH PLASMA
PENETRATION INSIDE THE MAGNETOSPHERE
svetlana rOSSOLENKO1,2, Elizaveta ANTONOVA1,2, YUri YERMOLAEV2, Igor KIRPICHEV2, Mikhail VERIGIN2, Natalia BORODKOVA2, Elena BUDNIK3
Institute of Nuclear
3 Centre d’Études et des Recherches des Rayonnements, Toulouse, France
mixing of magnetosheath and plasma sheet plasma in LLBL is studied on
of INTERBALL/Tail probe observations.
Variations of the fluxes of ions and electrons and the magnetic field are analyzed. The thickness of LLBL for a number of cases is evaluated.
The dependence of LLBL thickness on the changes of solar wind magnetic field and velocity is investigated. The connection between the solar
wind magnetic field direction and the turbulent fluctuations of magnetosheath magnetic field is analyzed. The influence of magnetosheath magnetic
field fluctuations on the magnetopause stress balance is discussed. It is shown that one of the main factors determining the formation and structure
of LLBL is the turbulent nature of magnetic field and plasma fluctuations in the magnetosheath.
Key words: low latitude boundary layer – magnetosheath – turbulent fluctuations.
MUTUAL PHENOMENA OF URANUS’ SATELLITES: FUTURE ROMANIAN PHOTOMETRIC OBSERVATIONS
Ştefan Gabriel Sorescu 1, 2
Institute of the
Cuţitul de Argint 5, 040557
Fulgerului 1, 900218,
Abstract. We present a
short history of mutual phenomena campaigns in
The tests we have made for this campaign, the main problems in observing the satellites, and the list of selected phenomena are also described.
Key words: Uranus’ satellites – photometry.
IS IC 51 A POLAR RING GALAXY?
Institute of the
Astronomical Observatory Cluj-Napoca
Str. Cireşilor 19, 400487 Cluj-Napoca, Romania
Abstract. A study of the
galaxy IC 51 is proposed, aiming to confirm whether
IC 51 is a polar ring galaxy or not, and to provide
more information on the dynamics of interactions between galaxies.
Key words: extragalactic astronomy – polar ring galaxy – neutral hydrogen – radio interferometry.