OBSERVATIONAL PROGRAMS
AND FIRST RESULTS
OF
SELECTED ASTEROID
OBSERVATIONS
AT RTT150
WITHIN
INTERNATIONAL COOPERATION
Zeki ASLAN1, Rustem GUMEROV2, Lyudmila HUDKOVA3, Anatoly IVANTSOV3,
IREK KHAMITOV1, Aleksey NEMTINOV2, Gennady PINIGIN3, Sergey ZELIKOV3
1 TUBITAK
National Observatory TUG
Akdeniz
E-mail:
aslan@tug.tug.tubitak.gov.tr
2
E-mail:
rgumerov@ksu.ru
3 RI
National Astronomical Observatory
E-mail:
pinigin@mao.nikolaev.ua
Abstract. We discuss the
tasks and programs for observations of selected
asteroids in 2005−2007 at RTT150 within the international cooperation
between
the observatories of TUG (
dynamical method; improvement of orbits of NEAs; study of physical
characteristics of selected asteroids via photometric observations. The
first
results
of astrometric observations of asteroids, performed at RTT150 in 2004
and during the first half of 2005, have shown the mean accuracy of a
single
position
of a minor planet in both coordinates to be ~50 mas up to magnitude 17 and about 100 mas up to
magnitude 21.5 for
NEAs. These results give evidence
on the great possibilities of RTT150 for
accurate astrometry of the minor bodies of the Solar System and on its
usefulness in the GAIA Follow-Up Program.
Internal standard error of a single
observation of brightness of an asteroid in Rc-band is about 0.01
magnitude at
about magnitude 17 and about 0.05 at
magnitude 20.
Key words: astrometry – photometry – asteroids − CCD observations.
ASTROMETRIC CALIBRATION OF STELLAR CLUSTERS
RADU POPESCU, PETRE POPESCU, PETRE PARASCHIV, ALIN NEDELCU
Astronomical
Institute of the
Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania
E-mail:
[pradu,
petre, paras, nedelcu]@aira.astro.ro
Abstract. In April 2005 a Romanian team performed
observations at
Belogradchick observatory in
telescope, endowed with a 1k
1k
Apogee 47P CCD camera. In order to calibrate celestial
frames, there have been taken several series of CCD
images of M35 open cluster.
After resampling and reassembling dithered frames into the final single
large
image, we have recomputed and investigated
the WCS (World Coordinate System)
solution
Key words: CCD astrometry – M35 – WCS solution.
THE ARMENIAN VIRTUAL OBSERVATORY – ArVO
AREG MICKAELIAN
Byurakan Astrophysical Observatory (BAO)
Byurakan
378433, Aragatzotn province,
E-mail:
aregmick@apaven.am
Abstract.
The Armenian Virtual
Observatory (ArVO) is a project of the Byurakan Astrophysical
Observatory (BAO)
aimed at the construction of a
modern system for astronomical data archiving,
extraction, acquisition, reduction, use and publication. ArVO is based
on the
Digitized First Byurakan
Survey (DFBS) and is the Armenian contribution to the
International Virtual Observatories Alliance (IVOA). ArVO’s main goal
is to
create an interoperability
data system for Armenian astronomy based on the
Armenian and world astronomy resources and according to the IVOA
standards.
Besides the DFBS, ArVO
will combine all other Byurakan archival data and modern
observations from the 2.6-meter telescope. ArVO also includes some
science
projects, such as the
development of an automatic
identification procedure using the low-dispersion spectra and all other
available databases, as well as optical identification of X-ray,
IR and radio
sources; development of an automatic search procedure for modeled
objects, and
automatic search for new bright AGN in
DFBS. ArVO website
is available at http://www.aras.am/arvo.htm.
Key words: virtual observatories – surveys – databases.
CCD ASTROMETRY USING GROUND-BASED TELESCOPES
PETRE POPESCU, RADU POPESCU, PETRE
PARASCHIV,
ALIN NEDELCU, OCTAVIAN BĂDESCU
Astronomical
Institute of the
Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania
E-mail:
[petre, pradu,
paras, nedelcu, octavian]@aira.astro.ro
Abstract. Small ground-based telescopes often allow
observations of interesting celestial bodies for a long period, in
order to fill
the gaps in the data obtained
by means of large telescopes. Besides, small
telescopes equipped with CCDs are often fast systems. This combination
is good
for performing the above
mentioned observations.
Key words: CCD astrometry − data reduction.
DYNAMICAL SYSTEM OF DATA MANAGEMENT IN ASTRONOMY
LIVIU ŞERBĂNESCU 1, MIHAI CARAMIHAI 2
1 Astronomical
Institute of the
Str.
Cuţitul de Argint 5, 040557
E-mail: livius@aira.astro.ro
2 “Politehnica”
University
Splaiul
Independenţei 515,
E-mail:
m.caramihai@ieee.org
Abstract. Astronomy assumes
a large amount of data with a large variety of
data type. Fast access to data, as well as transfer between working
teams,
presumes an interface with the users in a unitary way, and access to
the
distributed database systems. In this context it is necessary to
develop a
software
(ADSI – Astronomical Database System Interface) that will interface
all data type used by the database distribution systems.
Key words: astronomical databases – object representation.
COMPUTATION OF ASTEROID EPHEMERIS
GHEORGHE BOCŞA
Astronomical
Institute of the
Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania
E-mail:
gbocsa@aira.astro.ro
Abstract. We present the
computation method of an ephemeris, for a body in
an elliptic orbit, on the basis of orbital elements and of the
rectangular
coordinates of the Sun.
Key words: orbit computation – ephemerides – asteroids.
PETRE PARASCHIV1, ALIN
NEDELCU1, PETRE POPESCU1, TEODOR
NEGOIŢĂ2,
1 Astronomical
Institute of the
Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania
E-mails:
[paras, nedelcu,
petre, pradu, octavian]@aira.astro.ro
2 Romanian Institute for Polar Research
Bd.
Libertăţii 1, Bl. A,
3 National Institute for Research and Development in Isotopic and Molecular Technologies
Str.
Donath
71−103, P.O. Box 700, 400293 Cluj-Napoca, Romania
E-mail:
itim@oc1.itim-cj.ro
Abstract. The aim
of this project is to achieve a robotic telescope adapted to polar
environment
activity. After performing the technological study
containing the main
parameters and attaining goals, a study of astroclimate will be
performed by both
using the already obtained database and in
situ
determination at the Romanian-Australian scientific polar station
Law-Racoviţă. The module will be build following studies, projects and
testing
of
materials and components in
associates,
after a preliminary training. Observational results are intended to be
stored
in databases, analyzed and eventually home-processed. The
astro-geodetical
observation programs will be performed via satellite communications.
Key words: Antarctic astronomy – robotic telescopes.
PROCESSING
TIME CONTACTS FOR VENUS’
TRANSIT 2004 USING THE
HOUGH
TRANSFORM
VLAD TURCU, DAN MOLDOVAN
Astronomical
Institute of the
Astronomical
Observatory Cluj-Napoca
Str.
Cireşilor
19, 400487 Cluj-Napoca, Romania
E-mail:
vturcu@academie.cj.edu.ro,
dmoldovan@academie.cj.edu.ro
Abstract. CCD real-time
observations of Venus’ transit 2004 were obtained at
the Cluj-Napoca Observatory of the Astronomical Institute of the
Romanian
time series of frames (> 1000). Due
to the strong noise immunity of the Hough transform, the O−C
time contacts obtained are less than 2 seconds.
The present
processing method minimizes the extinction errors and, with careful
implementation algorithm, tends to the instrumental technical limits.
Key words: Solar system − Venus’ transit − contact timings − Hough transform.
LOCAL-SCALE GEOID DETERMINATION METHODS
PETRE POPESCU, RADU POPESCU, OCTAVIAN BĂDESCU
Astronomical
Institute of the
Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania
E-mail:
[petre, pradu,
octavian]@aira.astro.ro
Abstract. Among the tasks asked by modern geodesy
one can quote accurate determination of geoid correlated to local areas
on the
Earth.
Local vertical deflection determination allows the determination of the
geoid at local scale. The preliminary astrogeodetic observations
started
at
Key words: geoid model – vertical deflection.
MORE REFINED SOLUTIONS IN THE GYLDÉN-TYPE PROBLEM
DAN ŞELARU 1, VASILE MIOC 2, CĂTĂLIN CUCU-DUMITRESCU 1
Institute for Space Sciences
Str.
Mendeleev 21−25, 010362
E-mails: [danselaru, cucudumitrescu]@yahoo.com
Astronomical
Institute of the
Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania
E-mail:
vmioc@aira.astro.ro
Abstract. We resume and
consistently extend our previous researches
concerning the Gyldén-type problem (a two-body problem with
time-dependent
equivalent gravitational parameter). To approach most of the concrete
astronomical situations modelable in this way, we
consider a periodic small perturbation.
For the
nonresonant case, we present a second-order analytical solution. For
the
resonant case,
we adopt the most realistic astronomical situation: only one
dominant term of the Hamiltonian. In this case we point out a
fundamental model
of resonance, common to every resonant situation, and, moreover,
identical to
the first model of resonance (Breiter 2003). Considering the
simplest model of
periodic change of the equivalent
gravitational parameter, we find that all possible resonances are
confined to
the first
fundamental model.
Key words: celestial mechanics − Gyldén-type problem − Hori-Deprit methods − resonances.
FAMILIES OF ORBITS IN CONSERVATIVE FIELDS OF HÉNON-HEILES TYPE
MIRA-CRISTIANA ANISIU
“Tiberiu
Popoviciu”
CP 68,
400110
E-mail:
mira@math.ubbcluj.ro
Abstract. The
equations of the inverse problem of dynamics are used in order to
obtain planar
and spatial potentials of Hénon-Heiles type,
which give rise to some special
families of curves. The curves of such a family can be traced by a
material
point of unit mass, with suitable
initial conditions, moving under the action
of the specific potential. We determine the region where the motion is
possible, as well as the total
energy of the particle.
Key words: celestial mechanics – inverse problem of dynamics – families of orbits.
Resonances of the GyldÉn-type problem
CĂTĂLIN CUCU-DUMITRESCU1, VASILE MIOC2, DAN ŞELARU1
1 Institute for Space Sciences
Str.
Mendeleev 21−25, 010362
E-mail:
cucudumitrescu@yahoo.com, danselaru@yahoo.com
2 Astronomical
Institute of the
Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania
E-mail:
vmioc@aira.astro.ro
Abstract. We tackle the
Gyldén-type problem (a two-body problem with
time-changing equivalent gravitational parameter). In the most
interesting case
for astronomy: small-amplitude periodic variation, we study the
behavior of the
system in the neighborhood of resonances.
A partial averaging of the vector
field, combined with the introduction of a slowly-changing
timelike variable, leads to a
one-degree-of-freedom
system of ODE. Considering the simplest case of the
variation, we perform some numerical experiments. Even in this simplest
case,
the phase
portraits are very complex: a mixture of oscillation zones,
circulation zones and chaotic zones.
Key words: Gyldén-type problem − nonlinear particle dynamics − resonances.
PHOTOGRAVITATIONAL RESTRICTED THREE-BODY PROBLEM. ROLE OF THE TEST PARTICLE IN THE ROCHE GEOMETRY
RODICA ROMAN
Astronomical
Institute of the
Astronomical
Observatory Cluj-Napoca
Str.
Cireşilor
19, RO-400487 Cluj-Napoca, Romania
E-mail:
rroman@math.ubbcluj.ro
Abstract. Within
the framework of the
photogravitational circular restricted three-body problem, the
conditions for
the existence of the out-of-plane equilibrium
points are analyzed. We find that at most
two pairs of such points
can exist. For the stellar binary system RW Tauri, the existence of the
out-of-plane
equilibrium
points is possible if the test particle (considered as being made
up of ice) has a radius between 11.55 and 14 microns. Nevertheless in
the XMZ-plane only two
such points could be
found. For a test particle with the radius of 13.9 microns, the
equipotential
surfaces containing the out-of-plane equilibrium points are drawn
in the XMZ-plane.
Key words: celestial mechanics – photogravitational circular restricted three-body problem – libration points.
NOTE
ON THE CIRCULAR
RESTRICTED THREE-BODY
PROBLEM
WITHIN THE PHOTOGRAVITATIONAL
MODEL
OF CONSTANTIN POPOVICI
CIPRIAN CHIRUŢĂ 1, TIBERIU OPROIU 2
1 “Ion
Ionescu de la Brad”
Aleea
M.
Sadoveanu, nr. 3, 700490, Iaşi, Romania
E-mail:
kyru@univagro.iasi.ro
Astronomical
Institute of the
Astronomical
Observatory Cluj-Napoca
Str.
Cireşilor
19, 400487 Cluj-Napoca, Romania
E-mail:
toproiu@email.ro
Abstract. We
discuss the circular
restricted three-body problem within the framework of the
photogravitational
model proposed by the Romanian
astronomer Constantin Popovici. We establish the
differential equations of motion and make some comments on the
libration
points. Some numerical
applications in the Sun-Jupiter system are given.
Key words: celestial mechanics − circular restricted three-body problem − radiation pressure.
Equilibria of Hénon-Heiles’ Two-Body Problem
DUMITRU PRICOPI,
VASILE MIOC, MAGDA
STAVINSCHI
Astronomical
Institute of the
Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania
E-mail:
[dpricopi, vmioc,
magda]@aira.astro.ro
Abstract. We tackle the
two-body problem associated to Hénon-Heiles’ famous
potential. We find the equilibrium points and we describe the
flows in their
neighbourhood. The main features of the global flow are pointed out.
Key words: celestial mechanics – Hénon-Heiles’ model – equilibria.
METHODS FOR
REPRESENTING
ADRIAN DRĂGUŞAN, SERGIU LUPU
“Mircea
cel Bătrân”
Str.
Fulgerului 1–3,
Abstract. This
paper presents the most important methods for representing the
gravitational
potential. The classical and the most used method is the
spherical
harmonics-method. The figure of the Earth is very close to an
ellipsoid.
Spherical harmonics cannot describe precisely the expansion of the
gravitational potential between the reference sphere and the reference
ellipsoid. For this purpose we adapted a new method: the ellipsoidal
harmonics.
In the final part of the paper we present the results obtained with
programs in
Maple 8 and Visual C++.
Key words: celestial mechanics − geopotential.
PHOTOMETRIC REDSHIFTS TECHNIQUE FOR GALAXIES CLUSTERING DETECTION
NEDELIA ANTONIA POPESCU
Astronomical
Institute of the
Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania
E-mail:
delia@aira.astro.ro
Abstract. Using
the Z-PEG software (Le Borgne and Rocca-Volmerange 2002), we obtained
photometric redshifts for galaxies in the field of
3C 220.1 (z = 0.62) and 3C 34 (z =
0.689) radio galaxies. In both
fields, the presence of clustering features of galaxies with similar
redshifts
is
revealed. A comparison between the HST morphology of galaxies and the
model
spectral type of galaxy is also made.
Key words: cosmology – galaxies: photometric redshifts – clustering of galaxies.
THE BLACK HOLES DISTRIBUTION IN A 50 MPC NEIGHBORHOOD. STATISTICAL APPROACH
Sorin-adrian roman 1, peter l. biermann 2
1 Northeastern University
E-mail: roman.s@neu.edu
2 Max Planck Institute for Radioastronomy
Auf dem
Hügel 69, DE-53121 Bonn,
E-mail: plbiermann@mpifr-bonn.mpg.de
Abstract. The black hole mass is derived, starting
from observational data (taken in B band) and using adequate values for
the
distance between
Earth and the galaxies. Some ambiguous aspects and the
implications that follow are emphasized. Then, starting from the
relation
between the galaxy’s
luminosity and the mass of the black hole, we obtain a
distribution of the black holes in our
cosmic neighborhood. We compare our results with data
concerning the distribution of
galaxies at a larger
radius (Devereux and Hameed 1997), and we find that the number obtained
by
Devereux and
Hameed is close to what we obtained for the E type galaxy and
higher by approximately a factor of 2 for the Sa, Sb, and Sc type case.
Key words: black holes – galaxy’s luminosity.
SEARCH FOR PULSATIONS IN B AND A STARS. THE PROBLEM OF “MAIA”-VARIABLES
KIRIL PANOV
72,
Tsarigradsko Shosse, BG-1784 Sofia, Bulgaria
E-mail:
kpanov@astro.bas.bg
Abstract. This report
contains a brief outline of the problem of the
“Maia”-variables, i.e., pulsations in the spectral range B7−A2 on the
HRD.
Some
recent results are quoted and future perspectives are suggested.
Key words: variable stars – pulsations – “Maia”-variables.
THE CENTRAL-EAST-SOUTH-EUROPEAN BINARY STAR GROUP: SOME FIRST RESULTS
TIBOR HEGEDÜS1,
JÁNOS NUSPL2,
NEVYANA MARKOVA3, HARALAMBI
MARKOV3, HELEN
ROVITHIS-LIVANIOU4,
ISTVAN VINCE5, JÓZSEF
VINkÓ6
1 Baja Astronomical Observatory of Bács-Kiskun Country
H-6500
Baja, Szegedi útca, KT 766,
2 Konkoly
Observatory of the
H-1525
3 Institute of Astronomy, National Astronomical Observatory
4 Section
of Astrophysics-Astronomy and
Mechanics, Department of Physics,
Panepistimiopolis,
Zografos 157 84, Athens, Greece
E-mail:
elivan@phys.uoa.gr
5 Astronomical
Observatory of
Volgina
7, 11160
E-mail: ivince@aob.bg.ac.yu
6 Department
of Optics and Quantum
Electronics,
POB
406,
Abstract. The
Central-East-South-European Binary (CESEB) star-study group
was formed in 2003. The main
purpose
of this scientific
group is the combined spectral and photometric observations
of several selected eclipsing binaries, using the various small and
larger
telescopes
of the involved countries, as well as the subsequent analysis of the
data to be carried out with the same
way. Here, some first preliminary results,
concerning the radial velocity and
the light curve variations of our first target, that is the active W
UMa-type
binary LS Del are presented,
compared to old data and discussed.
Key words: variable stars – eclipsing binary systems – radial velocity and light-curve analysis − LS Del.
THE PROGRAM OF PHOTOMETRIC STUDY OF CATACLYSMIC VARIABLES IN STERNBERG ASTRONOMICAL INSTITUTE
IRINA VOLOSHINA, VALERIAN SEMENTSOV
Sternberg
Astronomical Institute of
Universitetskij
prospekt 13, 119992 Moscow,
E-mail:
vib@sai.msu.ru
Abstract. Within the
framework of a large observational project devoted to
the study of long-term photometric variability of cataclysmic
variables, which
has been
carried out in the Sternberg Astronomical Institute, numerous
photometric UBV and CCD observations were obtained. Here we present the
results
for most interesting
objects included in our program: old novae HR Del, V603
Aql, novae V2274 Cyg and V2275 Cyg (both came to the outburst in 2001),
and the
very unusual recent
nova V475 Sct together with two intermediate polars, V795
Her and GK Per (Nova Per 1901), the object with a very striking
evolution. All
observations were
carried out with the UBV photometer and CCD device on the
60-cm telescope of the Sternberg Astronomical Institute in
The light curves of these cataclysmic variables are constructed and
their color behavior is considered.
Key words: variable stars – cataclysmic systems – light curves − photometry.
FIRST PHOTOMETRIC OBSERVATIONS OF RECENTLY DISCOVERED BINARIES
EUGENIA
ANTONOPOULOU, NIKOLAOS
NANOURIS,
GIANNIS KONTOGIANNIS,
GIANNIS
GIANNIKAKIS, ODYSSEAS
DIONATOS
Department of Astrophysics, Astronomy and Mechanics
Panepistimiopolis
Zografou, GR-15784
E-mail:
eantonop@phys.uoa.gr
Abstract. We present
preliminary results of BVRI photometry of binary stars
out of an observing list of short period binaries without any
previous
multifilter observations. The purpose of this project is to obtain
photometric
elements and the absolute parameters for further
understanding of the
evolutionary processes for these systems. The observations took place
at
Kryonerion Astronomical Station (NOA).
Key words: variable stars – eclipsing binary systems – photometry.
ON THE DETECTION OF OUTLIERS IN O‑C CURVES
ALEXANDRU POP 1, MICHAEL BARBOSU 2
1 Astronomical
Institute of the
Astronomical
Observatory Cluj‑Napoca
Str.
Cireşilor
19, 400487 Cluj‑Napoca, Romania
E‑mail:
apop@academie.cj.edu.ro
2 SUNY Brockport, Department of Mathematics
350 New
Campus Dr., Brockport, NY 14420,
E-mail:
mbarbosu@brockport.edu
Abstract. In the analysis of
period variability phenomena occurring in variable stars we often have
to deal
with large data sets containing
especially visual observations over an interval
of time that sometimes exceeds a century. Different observers have
often
carried out
simultaneous observations (time of maximum/minimum light) on a
certain event. This paper deals with the problem of detection and
rejection
of
outliers in such situations.
Key words: variable stars − period variability − outliers.
THE SYMBIOTIC AND ECLIPSING BINARY AR PAVONIS: LATEST OBSERVATIONS AND FINDINGS
HELEN ROVITHIS-LIVANIOU 1, ALBERT JONES 2
1 Section of Astrophysics-Astronomy and Mechanics
Department
of Physics,
Panepistimiopolis,
Zografos 157 84,
E-mail:
elivan@phys.uoa.gr
2 Carter
Observatory, National Observatory of
Abstract. The
latest visual observational material and the corresponding light curves
of the
symbiotic and eclipsing binary AR Pav,
obtained during the last four years, are presented and discussed.
General
comments for the latest findings of AR
Pav are also made.
Key words: variable stars – symbiotic stars − eclipsing binaries – light curves − AR Pav.
A Possible Extension
of Stellingwerf’S
DUMITRU PRICOPI
Astronomical
Institute of the
Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania
E-mail:
dpricopi@aira.astro.ro
Abstract. We extend
Stellingwerf’s One-Zone stellar model by considering a
slow and uniform rotation that leads to
a very small
oblateness of the star. The matter in the core-surrounding shell
is supposed to consist of a mixture of ideal gas and radiation.
Key
words: astrophysics − variable stars.
WHERE ARE THE ROOTS OF THE FAST SOLAR WIND?
MIRUNA DANIELA
POPESCU 1,2, jOHN gERARD
DOYLE 1
1
E-mail: mdp@arm.ac.uk, jgd@arm.ac.uk
2 Astronomical
Institute of the
Str.
Cuţitul
de Argint 5, 040557 Bucharest, Romania
Abstract. A few million
tons of charged particles leave the Sun every
second. This continuous stream of particles – the solar wind – leaks
from the
Sun’s inner atmosphere, escaping its gravity. How is the solar wind
accelerated
to hundreds of km s-1, together with the chain of
heating processes
that generate and sustain the Sun’s hot corona has so far defied a
quantitative
understanding, despite the multitude of efforts
spanning the last half-century.
In our work, we analyze data acquired with the
holes, being particularly interested to find the fast
solar wind origins as low as possible in the solar atmosphere. Our
results
indicate that we have
not seen the fast solar wind starting as a steady outflow
in the transition region. Instead, we see bursts of short-time
brightenings,
possibly representing
bi-directional jets (explosive events) of different
scales, which, because of the open magnetic field structure, could pump
plasma
into the corona.
Key
words: solar atmosphere – solar wind –
data analysis.
SIGNIFICANT
ACOUSTIC ACTIVITY
IN AR10720
DIANA BEŞLIU-IONECSU1, 2, ALINA-CĂTĂLINA DONEA2, PAUL CALLY2,
CHARLES LINDSEY3
1 Astronomical
Institute of the
Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania
E-mail:
deanna@aira.astro.ro
2 School
of Mathematical Sciences,
Victoria
3168,
Australia
E-mail:
alina.donea@sci.monash.edu.au, paul.cally@sci.monash.edu.au
3 Colorado Research Associates Division Northwest Research Associates, Inc.
Abstract. We report
the recent discovery of one of the most acoustically powerful flare
detected to
date produced by the
X1.2 solar flare in AR10720. We
used helioseismic holography to image the acoustic source of the
seismic waves
produced by the flare.
Egression Power maps at 6 mHz point out a strong,
extended acoustic signature, which is the focus of the solar quake. At
approximately 20 minutes
after the appearance of the flare signature, we could
also see the seismic response of the photosphere to the energy
deposited by the
flare in the
form of “ripples” on the solar surface.
Key words: solar physics − flares − helioseismology.
CORONAL HOLE − MHD NUMERICAL SIMULATION
CRISTIANA DUMITRACHE
Astronomical
Institute of the
Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania
E-mail:
crisd@aira.astro.ro
Abstract. Starting with a
dipole magnetic configuration, 2D-MHD numerical
experiments were performed on different solar radii.
Our numerical experiments
treat locally the formation of the
coronal hole. The evolution of the magnetic field and plasma parameters
are
analyzed for β ≤ 0.1. The numerical values obtained by these
simulations are in
a good agreement with those given by the observational works.
Key words: Sun – coronal hole – numerical simulations.
SOLAR-ACTIVITY SIGNATURE IN THE TIME-EVOLUTION OF THE GEOMAGNETIC FIELD
CRIŞAN DEMETRESCU, VENERA DOBRICĂ
Str.
J.-L. Calderon 19−21,
E-mail:
crisan@geodin.ro
Abstract. The
relationship between the solar activity and short-term variations in
the geomagnetic
field has been known for a long time.
However, 95−98% of the observed
geomagnetic field has internal sources, being mainly produced by a
dynamo
process in the external
core of the Earth (the main geomagnetic field) and by
magnetic rocks in the lithosphere (the lithospheric field). The time
evolution
of the
main field is currently believed
to be characterized by intervals of constant secular variation
interrupted by episodes of sudden (1−3 years)
steps in the secular
acceleration, called geomagnetic jerks. The main characteristics of
11-, 22-,
and ~80-year variations, which are present
in the annual means of geomagnetic
elements at selected observatories with 100−150 years of data, being
superimposed on a steady field,
are presented and the relationship with the
solar activity is discussed. Consequences on the interpretation of
geomagnetic
jerks are discussed
as well.
Key words: solar activity − geomagnetic field − secular variation − geomagnetic jerks.
ASTRONOMERS AND PUBLIC EDUCATION
MAGDA STAVINSCHI
Astronomical
Institute of the
Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania
E-mail:
magda@aira.astro.ro
Abstract. Astronomy is more
and more attractive for the public, especially
due to the space missions. Unfortunately, the lack of special
lessons in school
and of dedicated journals alters the correct understanding of the
celestial
phenomena. The contribution of scientists becomes
in our days not only
necessary, but compulsory. How to do it and who has to do it are
problems not
easy to solve. We need a very thorough
analysis of the way in which scientific
information is communicated to
the general public: well done, it can be beneficial; otherwise it may
drive the
new generations away from research, away from the understanding of the
phenomena, but towards the neglection of the environment
and, eventually,
towards the neglection and destruction
of our own planet.
Key words: astronomy − education.
ASTRONOMY
EDUCATION IN
OLGA ATANACKOVIC-VUKMANOVIC
Department
of Astronomy, Faculty of
Mathematics,
Studentski
trg 16, 11000 Belgrade, P.O. Box
550,
E-mail:
olga@matf.bg.ac.yu
Abstract. Astronomy
education in elementary and secondary schools and at the
universities of
The list of the amateur astronomical societies in
concerning the participation in the International Astronomy Olympiad
are also
briefly described.
Key words: astronomy education
SUMMER
SCHOOL ON SPECTROSCOPY
AT
ROZHEN
RENADA KONSTANTINOVA-ANTOVA, LUBOMIR
ILIEV, ILIAN ILIEV,
HARALAMBI MARKOV,
DIMITAR KOLEV,
NEVYANA
MARKOVA,
NIKOLAY TOMOV
72,
Tsarigradsko Shosse, BG-1784 Sofia, Bulgaria
E-mail:
renada@astro.bas.bg
Abstract. Spectral
observations constitute a powerful tool for studying the conditions in stellar atmospheres, chemical composition,
and variability in stars, in general. The Bulgarian National
Astronomical
Observatory − Rozhen (BNAO) with the 2-meter telescope
and the high-resolution
spectral equipment provides possibilities for such observations. The existence of
professionals with experience
in spectroscopy
in
the principles of
spectroscopy and their practical application to different kinds of
stars. The benefit
for the future will be the enhancement
of the level of astronomical research in
stellar physics in the region, to motivate further astronomical
integration in
the region, and also to
stop the brain-drain of young astronomers from our
region.
Key words: stellar spectroscopy − education.
TOTAL
SOLAR ECLIPSE OF
ZEKİ
ASLAN 1, 2, TUNCAY
ÖZIŞIK
2
1 Akdeniz University, Faculty of Sciences and Arts, Physics Department
07058
E-mail: aslan@tug.tug.tubitak.gov.tr
2 TUBITAK National Observatory (TUG)
E-mail:
tuncay@tug.tug.tubitak.gov.tr
Abstract. A total solar
eclipse will take place on
Antalya
concerned. We give
brief information about the observing conditions and local activities
to be
carried out during the eclipse.
Key words: total solar eclipse.
NIKOLAEV ASTRONOMICAL
OBSERVATORY: A HISTORICAL,
ASTRONOMICAL, AND
ARCHITECTURAL MONUMENT OF THE
NORTHERN
GENNADY PINIGIN1, EVNIKA LINOVA2, GRIGORY PETROV1,
ZHANNA
POZHALOVA1, NINA OLSHANSKAYA1
1 Research Institute “Nikolaev Astronomical Observatory”
Observatornaya,1,
E-mail: pinigin@mao.nikolaev.ua
2 State Protection Service of Cultural Heritage
21,
Sichnevogo Povstanya Str., B1.20,
Abstract. Nikolaev
Astronomical Observatory (NAO) is a monument of
historical, astronomical, and architectural heritage of the Northern
Black-Sea
shore.
NAO is the oldest naval observatory in the
make-up and basic profile of astronomical research. NAO was founded
in 1821 by Admiral A. Greig as the naval observatory. The main object
of world
heritage
is the main building of the observatory, which was built during
1821−1829 observing the astronomical requirements. The unique ancient
astronomical instruments,
such as the meridian circle and portable vertical
circle made by Repsold firm, were preserved in NAO. The observatory has
a
collection of astronomical clocks
made in the 18th−19th centuries and a
collection of astronomical books published in the 17th−19th centuries.
Key words: world heritage – history of astronomical research – astronomical instruments – astronomical clocks.
METON’S CYCLE AND THE 86TH OLYMPIC GAMES
HELEN ROVITHIS-LIVANIOU1, PETER ROVITHIS2
1 Section
of Astrophysics-Astronomy and Mechanics, Department of
Physics,
E-mail: elivan@ phys.uoa.gr
2 Institute
of Astronomy and
Astrophysics, National Observatory of
Abstract. A big problem in
the preparation of the old Greek calendars, when
they became lunar-solar, was to find a correlation between integer
number of
tropical years and integer number of synodic months. This was
necessary,
because neither the tropical year nor the synodic month contain integer
number
of
days while the political year and the month had to. The suggestion of
such a
relation by Meton, known as Meton’s cycle, is described. Its
announcement date
(432 BC) coincides with the 86th Olympic Games, and it is believed that
it was
made known to the public during that particular Olympiad. Moreover, a
general
discussion concerning other time cycles is given.
Key
words: time cycles – Meton’s cycle –
ancient