EDUCATION  IN  ASTROMETRY

MAGDA STAVINSCHI1, WILLIAM van ALTENA2

1 Astronomical Institute of the Romanian Academy

Str. Cuţitul de Argint 5, 040557 Bucharest, Romania

E-mail: magda@aira.astro.ro

 

2 Yale University, New Haven, Connecticut, USA

E-mail: vanalten@astro.yale.edu

Abstract. The future of astrometric research is very exciting due to the SIM and GAIA astrometric space missions, which will provide
10–20 microarcsecond positions, parallaxes and proper motions for 109 stars. Innovative ground-based telescopes, such as the LSST,
are planned, which will provide less precise data for many more stars. The potential for studies of the structure, kinematics and dynamics
of our Galaxy as well as of the physical nature of stars and of the cosmological distance scale is without equal in the history of astronomy.
Hipparcos and the HST were astrometric successes only due to the dedicated work of specialists in astrometry that fought to maintain the
astrometric characteristics of those satellites and their data pipelines. It is ironic therefore that given this unparalleled treasure trove of data,
in two years not one course in astrometry will be taught in the US, leaving all astrometric education to Europe, China and Latin America.
Who will ensure the astrometric quality control for the JWT, SIM, GAIA, LSST, to say nothing about the current large ground-based facilities,
such as the VLT, Gemini, Keck, NOAO, Magellan, the LBT, etc.? We propose a renewal of astrometric education in the universities to prepare
qualified scientists for these unique opportunities so that the scientific returns from the investment of several billions of dollars will be maximized.
The universities, observatories and agencies should acknowledge their responsibility to hire qualified full time astrometric scientists to supervise
existing and planned astronomical facilities so that quality data should be obtained. The funding agencies are providing outstanding facilities.
Will the universities, institutes and observatories assume their responsibilities?

Key words: astrometry – education.

 

 

 

GROUND-BASED  ASTROMETRY  AT  THE  TIME  OF  THE  GAIA  SPACE  MISSION

WILLIAM  THUILLOT1,  JEAN-EUDES  ARLOT1,  MAGDA  STAVINSCHI2,

MIREL  BIRLAN1,2,  VALERY  LAINEY1,3

1 Institut de Mécanique Céleste et de Calcul des Éphémérides

IMCCE/Observatoire de Paris

77 av. Denfert Rochereau F-75014 Paris, France

E-mail: thuillot@imcce.fr, Jean-Eudes.Arlot@obspm.fr

 

2 Astronomical Institute of the Romanian Academy

Str. Cuţitul de Argint 5, 040557 Bucharest, Romania

E-mail: magda@aira.astro.ro

 

3 Royal Observatory of Belgium,

Av. Circulaire, 3 – Ringlaan 3, B-1180 Bruxelles – Brussels, Belgium

Abstract. The next space astrometry mission GAIA will be launched before 2012 with the purpose to perform a wide 3-D cartography
of the Galaxy. During this 5 years long mission many Solar-System objects will be scanned and measured. Each object will be observed
about one hundred times and a very accurate astrometry, down to 10 µas, will be carried out. Furthermore, since the limiting magnitude
will be 21 and observations could be made rather close to the Solar direction, many new Solar-System objects will certainly be discovered.

Therefore this mission will be a milestone in particular for astrometry of the Solar System. Several ground-based programs of observation
of Solar-System objects will probably have to be stopped or reoriented in order to remain relevant. Our paper intends to discuss these
circumstances and the relevance of selected observations. Several proposals are made for coordinating efforts in order to get a better
knowledge of these objects. Either autonomous programs or programs complementary to the GAIA mission are proposed. Small telescopes
will be still very useful for these programs.

Key words: space mission – astrometry – catalogue – follow-up.

 

 

 

GAMMA-RAY  BURST  AFTERGLOW  STUDIES  IN  TURKEY

Mehmet  EMIN  ÖZEL1,  Yasemin  KAÇAR1,  Volkan  BAKIŞ1,

Murat  OLUTAŞ2,  Umit  KIZILOĞLU3,  Tolga  GÜVER4

1 Çanakkale Onsekiz Mart University, Department of Physics, Çanakkale, Turkey

E-mail: m.e.ozel@comu.edu.tr

 

2 Abant İzzet Baysal University, Department of Physics, Bolu, Turkey

 

3 Middle East Technical University, Physics Department, Ankara, Turkey

 

4 University of Istanbul, Department of Astronomy, Istanbul, Turkey

Abstract. Gamma-Ray Bursts (GRBs), accidentally discovered by Vela satellites forty years ago, are transient celestial events, lasting
milliseconds to tens of minutes. They are the most powerful explosions in the whole Universe. About once per day, at a random location
in the sky, a shower of gamma-ray photons with 1 keV – 100 MeV energy appears and we cannot guess where they will occur next.
Hence their observing and studying were hard. To overcome these difficulties, astronomers designed special-purpose detectors such as
Robotic Optical Transient Search Experiment (ROTSE). To understand these events, scientists need to study afterglow emissions in X-rays,
optical and radio waves after or during a GRB. The ROTSE Project aims at achieving the detection of optical afterglow emission from the
GRB. The ROTSE system can move quickly on the coordinates of the burst, which is usually announced through Internet. Presently, the
international ROTSE collaboration includes the main coordinating group (running a station at
Los Alamos) and three stations located in Turkey,
Namibia
and Australia. Each of these telescopes is fully automated, forming a worldwide network. One of them, ROTSE-IIId, is located at
Antalya
, within the Turkish National Observatory (TUG) site and is functional since May 2004. In this work, after some historical notes and
afterglow detection statistics, the properties, goals, functions and the technology behind the Global ROTSE system installed around the world
will be summarized, with emphasis on
Antalya station results.

Key words: Gamma-Ray astronomy – Gamma-Ray Bursts – GRB afterglow emissions – GCN – BATSE – ROTSE.

 

 

 

NARROW-FIELD  ASTROMETRY  WITH  THE  PRIN-MERZ  ASTROGRAPH

PETRE  Popescu1,  RADU  Popescu1,  Gheorghe  BocŞa1,  PETRE  Paraschiv1, GHEORGHE  Huian2,  ALIN  Nedelcu1, LIVIU  ŞerbĂnescu1,  OCTAVIAN  BĂdescu1

1 Astronomical Institute of the Romanian Academy

Str. Cuţitul de Argint 5, 040557 Bucharest, Romania

E-mail: petre@aira.astro.ro

 

2 INCDMF-CEFIN

Şos. Pantelimon 6–8, Bucharest, Romania

E-mail: cefin@cefin.ro

Abstract. Early results of narrow-field CCD astrometry with a new CCD camera Apogee AP47P are presented. Despite the small field of view
(7.3×7.3 arcmin), a limiting magnitude of ~18 provides us stars enough to complete the astrometrical tasks. For the same reason we were obliged
to use catalogues with a denser stellar coverage as USNO A1.0 or the newer USNO B1.0, which include proper motions. All the images are
reduced using IRAF package software.

Key words: narrow field astrometry– limiting magnitude – data reduction.

 

 

 

ASTROMETRIC  SOLUTIONS  OF  ECLIPSING  BINARIES:  R CMA  AND  XY LEO

VOLKAN  BAKIŞ,  EDWIN  BUDDING,  OSMAN  DEMİRÇAN,  HİCRAN  BAKIŞ

Physics Department, Faculty of Science & Arts

Çanakkale University

Terzioğlu Campus, 17040, Çanakkale, Turkey

E-mail: bakisv@physics.comu.edu.tr

Abstract. Astrometric solutions, together with times of minimum, have been made for R CMa (HIP35487) and XY Leo (HIP49136)
to identify the wide companions to the eclipsing pairs. From these solutions, we derive the inclination of the wide orbit as 91
°.7 ± 4.7
and 94
°.4 ± 0.2 and the masses of the third bodies as 0.36 ± 0.2 and 0.98 ± 0.2 solar masses for R CMa and XY Leo, respectively.
This study confirms that the light-time travel effect can explain the sinusoidal O – C variation of the eclipsing systems.

Key words: eclipsing binary systems – triple systems – astrometry – light time effect.

 

 

 

COOPERATION  FOR  COMMON  USE  OF  SEE ASTRONOMICAL  DATABASE  AS  A  REGIONAL  VIRTUAL OBSERVATORY 
IN  DIFFERENT  SCIENTIFIC  PROJECTS

GENNADY  PINIGIN,  YURI  PROTSYUK,  ALEXANDER  SHULGA

Nikolaev Astronomical Observatory

Str. Observatorna 1, 54030 Mykolajiv-30, Ukraine

E-mail: yuri@mao.nikolaev.ua

Abstract. The activity of scientific collaborative and co-operative research between South-Eastern European (SEE) observatories is enlarged in the last time.
The creation of a common database as a regional virtual observatory is very desirable.
The creation of astronomical information resource with a capability of
interactive access to databases and telescopes on the base of the general astronomical database of the SEE countries is presented. This resource may be connected
with the European network. A short description of
the NAO database is presented. The total amount of the NAO information makes about 90 GB, the one obtained
from other sources – about 15 GB.
The mean diurnal level of the new astronomical information produced with the NAO CCD instruments makes from 300 MB
up to 2 GB, depending on the purposes and conditions of observations.
The majority of observational data is stored in FITS format. Possibility of using of VO-table
format for displaying these data in the Internet is studied. Activities on development and the further refinement of storage, exchange and data processing standards
are conducted.

Key words: astronomical database – virtual observatory.

 

 

 

COOPERATION  FOR  GROUND-BASED  PROVISION  OF  THE  PROGRAMME  “GAIA  FOLLOW-UP”  WITHIN  THE  INTERNATIONAL 
FRAMEWORK  OF  KSU  (
RUSSIA),  TUG  (TURKEY)  AND  NAO  (UKRAINE)

ZEKI  ASLAN1,  RUSTEM  GUMEROV2,  IREK  KHAMITOV1,

GENNADY  PINIGIN3,  ALEXANDER  SHULGA3

1 Turkish  National Observatory

TUG, Akdeniz Üniversitesi Yerleşkesi, 07058 Antalya, Turkey

E-mail: aslan@tug.tug.tubitak.gov.tr

 

2 Kazan State University

18 Kremlevskaya St., 420008 Kazan, Russia

E-mail: rgumerov@ksu.ru

 

3 National Astronomical Observatory

1 Observatornaya St., 54030 Nikolaev, Ukraine

E-mail: pinigin@mao.nikolaev.ua

Abstract. In a joint project of international collaboration between KSU (Russia), TUG (Turkey) and NAO (Ukraine), positional and photometric observations of small
Solar System bodies down to 20 magnitudes connected with GAIA project are planned using the 1.5 m telescope RTT150 equipped with CCD cameras and computer
control. Additionally, observations of the brighter objects (down to 18 mag) will be made with the CCD telescopes of NAO. It is stressed that an alert system of observations
seems to be necessary in order to catch more data on these targets and follow-up from the ground. P
hotometric observations of occultations of stars by asteroids are also planned.

Key words: astrometry – photometry – small Solar System bodies.

 

 

 

NEAR-IR  SPECTROSCOPY  OF  KARIN  FAMILY  OF  ASTEROIDS

Mirel  Birlan 1,2

1 Institut de Mécanique Céleste et de Calcul des Ephémérides, Observatoire de Paris

77 av. Denfert-Rochereau, 75014 Paris Cedex, France

E-mail: Mirel.Birlan@imcce.fr

 

2 Astronomical Institute of the Romanian Academy

Str. Cuţitul de Argint 5, 040557 Bucharest, Romania

Abstract. The asteroid 832 Karin belongs to the large family of Koronis, located in the main belt. Cluster analysis and tests performed
by Nesvorný et al. (2002) and Nesvorný and Bottke (2004), reveal a family of asteroids grouped around 832 Karin. Backward numerical
integrations unveiled their orbits convergence to the same orbital elements only 5.7 million years ago. This could be the consequence of the
breakup produced by the collision of two bodies from the main belt and thus, the youngest family if asteroids ever known. Our purpose was
to investigate the spectral region 0.8–2.5 micron in order to obtain information concerning the physics and mineralogy of Karin members. The
paper presents preliminary results of near-IR spectroscopy for three of this family members: 832 Karin,
13765 Nansmith and 13807 (1998 XE13).

Key words: asteroid – family – spectroscopy.

 

 

 

IMAGE  PROCESSING  OF  HIGH-SPEED  CELESTIAL OBJECTS

ALIN  NEDELCU,  RADU  POPESCU,  OCTAVIAN  BĂDESCU

Astronomical Institute of the Romanian Academy

Str. Cuţitul de Argint 5, 040557 Bucharest, Romania

E-mail: {nedelcu, pradu, octavian}@aira.astro.ro

Abstract. In order to show the capabilities of the modernized astrograph, some observational tests of high-speed objects were performed.
The exposure time and the highly accurate metrology system have been conceived in order to monitor, focus on, and track the high-speed
objects. The ultra-sensitive CCD camera based on a back illuminated chip, allows to this instrument to “track” celestial objects up to
18 magnitudes, summing images with an exposure time that does not exceed 10 minutes.

Key words: astrometry – high-speed objects – CCD tracking.

 

 

 

STUDY  OF  THE  MAGNITUDE  EQUATION  IN  NOVA  STARS  OBSERVATIONS

Valerian  SementSov,  Irina  VolosHina

Sternberg Astronomical Institute

Moscow State University

Universitetskij Prospekt 13, Moscow, Russia

E-mail: vib@sai.msu.ru

Abstract. The preliminary results of determination of the magnitude-coordinates dependencies from CCD observations of two recent novae are presented.

Key words: variable stars – nova stars – CCD data – magnitude equation.

 

 

 

MIGRATION  VELOCITIES  OF  ASTEROIDS  FROM  MBA  TO  NEAS  AND  CENTAURS

ANATOLY  KAZANTSEV

Astronomical Observatory of Kyiv National Taras Shevchenko University

Str. Observatorna 3, 04053 Kyiv, Ukraine

E-mail: ankaz@observ.univ.kiev.ua

Abstract. Numerical calculations of evolution of some thousands asteroid tentative orbit in the zones of commensurabilities with Jupiter
with account of nine planets and three asteroids are performed. The integration intervals reached 300 thousand years. Some orbits transfer
to NEAs orbits, and some – to similar to Centaurs’ ones.
Migration velocities of asteroids from MBA to NEAs and Centaurs are estimated.

Key words: asteroids – commensurability – Centaurs – near-Earth asteroids.

 

 

 

CHAOTIC  DYNAMICS  OF  ASTEROIDAL  SATELLITES

DAN  ŞELARU1,  VASILE  MIOC2, CĂTĂLIN  CUCU-DUMITRESCU1,  MARIAN  GHENESCU1

1Institute for Space Sciences

Str. Mendeleev 21-25, 010362 Bucharest, Romania

E-mails:{danselaru, cucudumitrescu}@yahoo.com, mariang@softrust.ro

 

2Astronomical Institute of the Romanian Academy

Str. Cuţitul de Argint 5, 040557 Bucharest, Romania

E-mail: vmioc@aira.astro.ro

Abstract. We use the planar, circular, restricted three-body problem (with a Schwarzschild-type field generated by the primary) to
model the dynamics of a moonlet around a prolate asteroid under the perturbative influence of the Sun. We show that there exists a
continuous range of parameters for which the “unperturbed” problem asteroid-satellite admits a homoclinic orbit. We estimate the
Melnikov integral for the perturbed problem, showing that it has simple zeroes. This means chaotic behaviour (unpredictable motion)
of the moonlet for an open set of initial data.

Key words: celestial mechanics – asteroidal satellites – chaotic dynamics.

 

 

 

PERSISTENCE  OF  PLANETARY  RINGS  UNDER  THE  INFLUENCE  OF  THE  ANISOTROPICALLY  RE-EMITTED  SOLAR  RADIATION

VASILE  MIOC1,  MIRA-CRISTIANA  ANISIU2,  MAGDA  STAVINSCHI1

1 Astronomical Institute of the Romanian Academy

Str. Cuţitul de Argint 5, 040557 Bucharest, Romania

E-mails: vmioc@aira.astro.ro, magda@aira.astro.ro

 

2 T. Popoviciu Institute of Numerical Analysis of the Romanian Academy

P.O.Box 68, 400110 Cluj-Napoca, Romania

E-mail: mira@math.ubbcluj.ro

 

Abstract. The solar radiation has a destabilizing influence on planetary rings. The shepherding satellites explain the persistence of these structures,
but the observational evidence for such satellites is still very weak. This paper studies the existence of periodic orbits of rings’ particles under a strongly
destabilizing perturbing factor: the solar radiation re-emitted anisotropically by the “landlord” planet. To this end we use Maxwell’s model of Saturn’s
rings, but enriching the respective potential with the terms corresponding to the planet’s oblateness and to re-emitted radiation. This (n+1)-body problem
can be split into n identical two-body problems. To prove the persistence of periodic solutions, we use two basic facts: (1) the potential generates a strong
force in Gordon’s sense; (2) the vector field of the problem exhibits the symmetries Si, i = 1,2,…,7. We prove that for any pre-assigned period T there
exist infinitely many Si-symmetric (i = 2,3) periodic solutions of the problem.

Key words: celestial mechanics – planetary rings– variational methods.

 

 

 

INVESTIGATIONS  OF  THE  SOLAR  SYSTEM  SMALL  BODIES  AT  KARAZIN  KHARKIV  NATIONAL  UNIVERSITY

DMITRIJ  LUPISHKO

Institute of Astronomy of the Karazin Kharkiv National University

Kharkiv, Ukraine

E-mail: lupishko@astron.kharkov.ua

Abstract. Astronomers of Karazin Kharkiv National University were the first to start the systematic study of physical properties of asteroids in the former
Soviet Union
. The first photometric observations of asteroids were carried out in 1977 at Gissar Observatory (Tajikistan) together with our colleagues of the
Institute
of Astrophysics
in Dushanbe. Since then many asteroid research programs have been launched at the Astronomical Observatory (Institute of
Astronomy since 2001) of Karazin Kharkiv National University, such as: photometric studies of asteroid shapes and rotations; photometry and polarimetry
of M-type asteroids and their meteorite analogues; asteroid magnitude-phase dependences and opposition effect of brightness; polarimetry of CMEU-asteroids
and their taxonomy; polarization-phase dependences and opposition effect of asteroid polarization; UBVRI-polarimetry and spectral dependence of asteroid
polarization; scattering properties of asteroid surfaces; optical properties and rotation of near-Earth asteroids (NEAs), the follow-up astrometric observations
of newly discovered NEAs, and others. Many observational programs were carried out in collaborations with our colleagues in Tajikistan, Crimea (Ukraine),
Poland, Czech Republic, Germany, Italy, Sweden and the USA. Since 1995 the comets have also become the objects of attention of our group and polarimetric
and photometric observations of comets are carried out regularly.

Key words: asteroids – comets – photometry – polarimetry.

 

 

 

OBSERVATIONS  OF  STAR  OCCULTATIONS  IN  KIEV  BY  THE  “SPALAKH”  TV  SYSTEM

Valery  KLESHCHONOK1,  LILYA  KAZANTSEVA1,  VICTOR  KISLYUK2,

NICOLAY  BUROMSKY1

1 Astronomical Observatory, Taras Shevchenko Kiev National University

Observatorna Street 3, Kiev 53, 04053 Ukraine

E-mail: klev@observ.univ.kiev.ua

 

2 Main Astronomical Observatory, NAS of Ukraine

Akademika Zabolotnoho St. 27, Kiev, 03680 Ukraine

Abstract. The new television system “Spalakh” is used for observing star occultations in the Astronomical Observatory of the Kiev University. Results
of observation of star occultations are given. Some occultations that show an opportunity of the television system are described in details. The project
of creation of the network for observation of star occultations and mutual phenomena in planetary satellite systems with similar television systems is described.
Opportunities of such a network for studying the shape and kinematics of celestial bodies are analyzed.

Key words: television observations – occultations.

 

 

 

DIGITAL  PLATE  PRE-PROCESSING  USING  FUZZY  TECHNIQUES

MIHAI  CARAMIHAI1,  LIVIU  ŞERBĂNESCU2

“Politehnica” University Bucharest

Splaiul Independenţei 515, Bucharest, Romania

E-mail: m.caramihai@ieee.org

 

Astronomical Institute of the Romanian Academy

Str. Cuţitul de Argint 5, 040557 Bucharest, Romania

E-mail: livius@aira.astro.ro

Abstract. The photographic plates that represent astronomical objects are scanned with a 2400 dpi. The maximal dimension of the
plates is 24x24 cm. The scanned file dimension is 100 Mb, taking long processing times. Taking in consideration that the useful information
existing on the plate is under 1% it was adopted the translation (conversion) information method to modify it from the existent format in
another one that allows to store only the useful information. The useful information was obtained applying fuzzy methods for the recognition
of the astronomical objects. The fuzzification/defuzzification information methods were analytically constituted and are based on the measurement
micrometric machine. The observed signal was decomposed into two components: the useful signal (or signal of interest) and the noise. Generally,
the gray-level images will be the threshold to calculate geometrical measures such as area, perimeter, diameter, compactness, etc. of an object.
The standard approach to image analysis and recognition begins by segmenting the image into regions and computing various properties of and
relationships among these regions. It is not always obvious how to measure geometrical properties of fuzzy sets, but definitions have been given and
basic properties established for a variety of such properties and relationships, including connectedness and surroundness, convexity, area, perimeter
and compactness, extent and diameter. The final information, obtained with fuzzy techniques, is represented by the relative position and relative
magnitude of the astronomical objects identified on the photographic plate
.

Key words: fuzzy logic – image reconstruction – filtering – pre-processing.

 

 

 

ASTROMETRIC  PLATE  CATALOGUES  IN  THE  WFPDB

KATYA  TSVETKOVA 1,   MILCHO  TSVETKOV 1,  MAGDA  STAVINSCHI 2,

ALAIN  FRESNEAU 3,  PATRICIA  LAMPENS 4

1 Institute of Astronomy, Bulgarian Academy of Sciences

72 Tsarigradsko Shosse Blvd., Sofia-1784, Bulgaria

E-mail: katya@skyarchive.org

 

2 Astronomical Institute of the Romanian Academy,

Str. Cuţitul de Argint 5, 040557 Bucharest, Romania

E-mail: magda@aira.astro.ro

 

3 Astronomical Observatory, Strasbourg

11, rue de l'Université, 67000 Strasbourg, France

E-mail: fresneau@astro.u-strasbg.fr

 

4 Royal Observatory of Belgium,

3 Ringlaan, B-1180 Brussels, Belgium

E-mail: patricia.lampens@oma.be

Abstract. The astrometric plate catalogues included in the Wide-Field Plate Database (WFPDB, http://www.skyarchive.org) are presented.
The WFPDB with its 375 archives, containing more than 2 130 000 plates obtained with professional telescopes of 125 observatories worldwide,
is now the basic source of information for the archived observations. Their importance is in connection with analyzing of the long-term variations
(sometimes more than a century) of the positions, orbits or dimensions of a lot of celestial objects or their prediscovery history. At present there
is an on-line access to the descriptive data for 377 687 plates from 92 archives through the WFPDB updated version in the Sofia Sky Archive
Data Center (SSADC). Archives of selected digitized plates are under preparation.

Key words: astrometry –astrometric catalogues – databases – Carte du Ciel project.

 

 

 

COMPILED  CATALOGUE  OF  REFERENCE  STARS AROUND  43  EXTRAGALACTIC  RADIO  SOURCES

Vladimir  Rylkov1,  Anna  DementYeva1,  NaTALIa  NarizhnaYa1,

Nadezhda  MAIGUROVA2,  Gennady  Pinigin2,  Yuri  Protsyuk2,

Gheorghe  BocŞa3,  Petre  Popescu3

1 Main Astronomical Observatory of the Russian Academy of Sciences

Pulkovskoe Shosse 65/1, 196140 St. Petersburg-140, Russia

E-mail: vryl@gao.spb.ru

 

2 Nikolaev Astronomical Observatory

Str. Observatorna 1, 54030 Mykolayiv-30, Ukraine

E-mail: pinigin@mao.nikolaev.ua

 

3 Astronomical Institute of the Romanian Academy

Str. Cuţitul de Argint 5, 040557 Bucharest, Romania

E-mail: petre@aira.astro.ro

Abstract. Some differential catalogues of reference stars around extragalactic radio sources obtained from photographic and CCD
observations by different observatories are considered. A compiled catalogue of star positions in fields 30'x 30' for the reduction of
optical observations ERS on telescopes endowed with CCD cameras is intended. Photographic observations fields around of 74 ERS
were made in Pulkovo observatory, around 115 ERS – in observatory of Kiev university, around 188 ERS – in the Astronomical Institute
of the Romanian Academy in Bucharest, 208 fields around ERS in Nikolaev observatory on telescope with CCD camera were obtained.
As first results the reduction techniques for results of observations to uniform compiled catalogue are shown. Astrometric positions for 5500
stars brighter than 16 magnitude for 43 fields around ERS are presented. A comparison of our results with those of other authors is made.

Key words: astrometry – reference stars – extragalactic radio source field.

 

 

 

Relative  positioning  of  geoid-ellipsoid  using  vertical  deviation

Octavian  BĂdescu1,2,  PETRE  POPESCU2,  RADU  POPESCU2

1 Technical University of Civil Engineering

Bd. Lacul Tei 124, Bucharest, Romania

E-mail: octavian@aira.astro.ro

 

2 Astronomical Institute of the Romanian Academy

Str. Cuţitul de Argint 5, 040558 Bucharest, Romania

E-mail: petre@aira.astro.ro, pradu@aira.astro.ro

Abstract. The angular differences between local vertical direction (plumb line) defining the geoid, and normal to the ellipsoid surface,
also called vertical deflection, are not negligible at all. These differences can reach sometimes values of tens of arcseconds. Astro-geodetical
methods of determining vertical deflection are more effective for local accurate geoid determination than other methods, i.e. gravimetry.
Nowadays, the astro-geodetic compilation of the geoid can be done in absolute values, by combining GPS satellite techniques with star
tracking CCD technology. Through the introduction of an adequate matrix of weights, we take into account the unequal weights of all
direct measurements: angular measurements and times at the chronometer. Applying the theory of conditional measurements with unknowns,
we get a rigorous algorithm for the determination with maximum efficiency of all three fundamental elements of astronomical geodesy.

Key words: astrometry – geodesy – astronomy – vertical deviation.

 

 

 

ASTROMETRY  IN  ODESSA  UNIVERSITY

NATALIYA  BAZYEY

Odessa Astronomical Observatory, Odessa, Ukraine

E-mail: Ii1966@mail.ru

Abstract. We present a survey of the astrometric activities in Odessa University Observatory. On the basis of the meridian observations
with the Repsold meridian circle, the collaborators of the observatory published about 40 catalogues of accurate stellar positions.
The importance of cooperation with other astronomical institutions (Pulkovo,
Kiev, Nikolaev) is pointed out.

Key words: astrometry – observations – meridian circle.

 

 

 

SHIP’S  COORDINATES  VIA  SOLAR  CIRCUMMERIDIAN  OBSERVATIONS

STELIAN  COJOCARU,  FLAVIUS  OTINCELESCU,  ADRIAN  DRĂGUŞAN

“Mircea cel Bătrân” Naval Academy

Str. Fulgerului 1–3, Constanţa, Romania

E-mail: cojocarus@yahoo.com

Abstract. We introduce an original method used to determine the ship’s astronomical position based on Sun’s altitude measurements
near the meridian passage. The paper introduces the classical method of Saint-Hillaire for determining the ship’s position from
simultaneous measurements to heavenly bodies and analyses a practical example comprising 33 measurements used both to determine
the ship’s position and to evaluate the results.

Key words: solar observations – navigation.

 

 

 

ASTROMETRY  WITH  THE  50/70  SCHMIDT  TELESCOPE OF  THE  BULGARIAN  NATIONAL  ASTRONOMICAL OBSERVATORY    ROZHEN

VIOLETA  Ivanova1,  TANYU  Bonev1,  GORDANA  Apostolovska2,

GALIN  Borisov1,  VLADIMIR  Krumov1

1 Institute of Astronomy, Bulgarian Academy of Sciences

72, Tsarigradsko Chaussee Blvd., BG-1786 Sofia, Bulgaria

E-mail: ivanova@astro.bas.bg

 

2 Institute of Physics, Faculty of Natural Sciences and Mathematics

P.O.Box 162, 100 Skopje, Republic of Macedonia

E-mail: gordanaa@iunona.pmf.ukim.edu.mk

Abstract. We present the main results from astrometric observations of asteroids made at the Bulgarian National Astronomical
Observatory – Rozhen. We discuss the first observations with the Schmidt telescope in scanning mode for search of asteroids.

Key words: astrometry – asteroids – comets.

 

 

 

PLANETARY  RINGS  STABILITY:  QUALITATIVE APPROACH

VASILE  MIOC,  MAGDA  STAVINSCHI

Astronomical Institute of the Romanian Academy

Str. Cuţitul de Argint 5, 040557 Bucharest, Romania

E-mail: vmioc@aira.astro.ro, magda@aira.astro.ro

 

Abstract. We tackle Maxwell’s (n+1)-body problem within the case of an oblate central planet. Such a problem can be split
into n identical two-body problems, whose solution is already known. The cases of stable periodic and quasiperiodic motions
are pointed out. These results are valid for both rings and massive satellites.

Key words: celestial mechanics – planetary rings and satellites – stability.

 

 

 

RT  AND:  MULTIPERIODIC  ORBITAL  PERIOD VARIABILITY,  RESONANCE,  AND  THE  HYPOTHESIS  OF  THE  LIGHT-TIME  EFFECT

ALEXANDRU  POP,  RODICA  ROMAN

Astronomical Institute of the Romanian Academy

Astronomical Observatory Cluj-Napoca

Str. Cireşilor 19, 400487 Cluj-Napoca, Romania

E-mail: apop@academie.cj.edu.ro, rroman@math.ubbcluj.ro

Abstract. The preliminary analysis of the photoelectric times of primary minimum light of RT And through the methodology used in case of pulsating stars
revealed a possible multiperiodic behaviour of its orbital period variability, with possible 3:1 and 5:1 resonance phenomena. The interpretation of the
emphasized periodicities 29.4 yr, 9.56 yr, and 5.860 yr found in the O – C curve as caused by the light-time effect led to M sin i values for the hypothetical
companions of 11.77, 5.53, and 3.97 MJupiter, respectively.

Key words: variable stars – eclipsing binary systems – period variability – light-time effect.

 

 

 

ROMANIAN  INSTRUMENTS  AND  DATABASES:  AN  ATTEMPT  TO  CAPITALIZE  THE  ASTRONOMICAL  HERITAGE

PETRE  POPESCU,  GHEORGHE  BOCŞA,  ALIN  NEDELCU

Astronomical Institute of the Romanian Academy

Str. Cuţitul de Argint 5, 040557 Bucharest, Romania

E-mail: [petre, gbocsa, nedelcu]@aira.astro.ro

Abstract. The most valuable things of our astronomical heritage are instruments and databases. The formation of databases, the storage and
format were performed under the super vision of the Wide-Field Archives Database UAI Working Group. Databases were organized and resized
in better condition being able to be used. Most of instruments are the living images of an epoch, of former methods and observation procedures.
In spite of time, there are some optical qualities, which must be taken into account. Depends on astronomers’ skill whether they preserve an instrument
or not. An analysis of the optical and mechanical system must be performed to evaluate whether the instrument can be modernized, or must be
preserved in the original shape. The paper shows some results obtained at the Astronomical Institute of the
Romanian Academy.

Key words: instruments –databases.

 

 

 

THE  ECLIPSING  BINARY  TZ  DRA

HELEN  ROVITHIS-LIVANIOU1,  PETER  ROVITHIS2,  LEONIDAS  GEORGOPOULOS1,

DAVID  MKRTICHIAN3

1 Section of Astrophysics-Astronomy & Mechanics, Dept. of Physics, Athens University Panepistimiopolis, Zografos 157 84, Athens, Greece

E-mail: elivan@ cc.uoa.gr

 

2 Institute of Astronomy and Astrophysics, National Observatory of Athens

P.O. Box 20048, Athens 118 10, Greece

 

3 Astronomical Observatory, Odessa National University

Shevchenko Park, 65014 Odessa, Ukraine

Abstract. The light curves of the eclipsing binary TZ Dra, obtained with the 40-cm Cassegrain reflector of the Athens University and an
ST8/SBIG CCD camera equipped with four filters (BVRI) in 2002, are analyzed and discussed. A set of preliminary elements for TZ Dra
was found, and there are indications that the primary component of this binary is a pulsating variable.

Key words: eclipsing binaries – light curve analysis – TZ Dra.

 

 

 

CCD  observations  of  comets  at  the  Astronomical  Institute  of  Kharkov  National  University

Vitaly Filonenko, Fiodor Velichko, Sergey Velichko, Roman Krymsaljuk

Astronomical Institute of V. N. Karazin Kharkov National University

Sumskaja str. 35, Kharkov, Ukraine

E-mail: filonenko@astron.kharkov.ua

Abstract. Some results of astrometric CCD observations of four comets are presented. On the basis of the astrometric and photometric
CCD observations of comet C/2001 A2 (LINEAR) a new observational phenomenon of cometary outburst activity has been discovered.

Key words: comets – CCD observations – astrometry – photometry.

 

 

 

Local  reference  system  of  12  extragalactic radiosources  used  for  radio-optical connection

PETRE  Popescu,  RADU  Popescu,  GHEORGHE  Bocsa,  PETRE  Paraschiv,

ALIN  Nedelcu,  LIVIU  Şerbanescu,  OCTAVIAN  Badescu

Astronomical Institute of the Romanian Academy

Str. Cuţitul de Argint 5, 040557 Bucharest, Romania

E-mail: petre@aira.astro.ro

Abstract. Within the framework of the regional collaboration, we started a new campaign for CCD observations of the optical counterparts
of extragalactic radiosources defining ICRF. The observations were performed between 10–17 October 2004 at Belogradchik Observatory (Bulgaria)
using the 60 cm Cassegrain telescope endowed with a 1k
´1k Apogee 47P CCD camera, leading to a field of size 6.16' with scale of 0.722''/pixel
in 2
´2 binned mode. The astrometric reduction is done using three high-density astrometric catalogs: USNO B1.0, 2MASS and UCAC2. The first results
are presented in this paper.

Key words: astrometry – reference systems.

 

 

 

SOFTWARE  TECHNIQUES  FOR  ANALYZING  CELESTIAL  OBJECTS  ON  PHOTOGRAPHIC  PLATES

Liviu  ŞERBĂNESCU1,  MIHAI  CARAMIHAI2,  Carmen  TOMA2,  Şerban  GĂLOIU2, Alina  ŞERBAN2

1 Astronomical Institute of the Romanian Academy

Str. Cuţitul de Argint 5, 040557 Bucharest, Romania

E-mail: livius@aira.astro.ro

 

2 “Politehnica” University Bucharest

Splaiul Independenţei 515, Bucharest, Romania

E-mail: m.caramihai@ieee.org

Abstract. The automatic detection from the catalog for the astronomical objects from photographic plates (and implicit their identification)
is necessary for a better use of the photographic plates library that exists at the Astronomical Institute of the
Romanian Academy. To identify
the astronomical objects on the photographic plates we need information regarding relative magnitude and relative position on the plate, on the
one hand, and the stellar catalogue in electronic format, on the other hand. To set up a reference system is necessary for the user to identify
precisely on the plate two objects from the catalogue. During the taking over of the coordinates and magnitudes of the two astronomical
objects is created a correspondence between the catalogue and the database of the astronomical objects from the plate. In addition, it is
necessary to establish an admissible error for the objects correspondence. Implementation of SQL queries makes possible the finding of the
correspondence. As result to the queries, we will get two tables: one containing the identifier of the astronomical object, its coordinates and
the magnitudes of the objects from the plate that have been found in the catalogue, and the second containing the coordinates and the magnitudes
of the objects from the plate that have not been found in the catalogue. It is possible to extend the correspondence to more stellar catalogues,
and so the list with unidentified objects is reduced and the certainty for the identified objects in all catalogues increase. In this case, the
references system will be chosen starting from all catalogues included in the software.

Key words: astrometry – stellar catalogues – photographic plates.

 

 

 

THE  CATALOGUE  OF  REFERENCE  STARS  AROUND  72  GALACTIC  RADIO-STARS

VLADIMIR  RYLKOV,  NATALIA  NARIZHNAYA

Main Astronomical Observatory of the Russian Academy of Sciences

Pulkovskoe Shosse 65/1, 196140 St. Petersburg-140, Russia

E-mail: vryl@gao.spb.ru

 

Abstract. At Pulkovo the Pul GRS program of the photographic observations of stars around 116 Galactic Radio Sources (GRS) from
Hipparcos Input Catalogue started with the Pulkovo Normal Astrograph in autumn 1994. Till now the positions of more than 13000 stars
for 72 radio-star fields have been obtained. The equatorial coordinates of 72 galactic radio-stars on J2000.0 to FK5 system are tabulated.

Key words: reference stars – compiled catalogue – galactic radio-stars