THE
OF ROMANIAN ASTRONOMY
MAGDA STAVINSCHI, VASILE MIOC
Astronomical
Institute of the
Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania
E-mail:
magda@aira.astro.ro,
vmioc@aira.astro.ro
Abstract. On
back to the dawn of the first millennium. The 19th
century brought the modernization of Romanian astronomy in European
context. By
coincidence, another
observatory was set up the same year on a Romanian
territory (today in the
survey
of the most important events and personalities of the Romanian
astronomy,
especially in the context of the new international cooperation wave in
which
Romania
Key words: history of astronomy – Romanian astronomy – centenary of the Bucharest Astronomical Observatory.
EVALUATION OF ASTROPHYSICALLY
USEFUL PARAMETERS FOR LaO
MOLECULE
PONSAMY SRIRAMACHANDRAN1, RAMACHANDRAN
SHANMUGAVEL1, NARAYANAN
RAJAMANICKAM1, SOMASHEKAR PUNDALIKARAO BAGARE2
1Physics
Research Centre,
E-mail:
nrmanickam@rediffmail.com
2Indian
Institute of Astrophysics, Kodaikanal and
Abstract. Vibrational
transition probabilities namely Franck-Condon (FC)
factors and r-centroids for the band
C2Π3/2–A’2Δ5/2, C2Π1/2–A’2Δ3/2, C2Π3/2–X2Σ+,
and C2Π1/2–X2Σ+,
systems of Lanthanum
Oxide (LaO) molecule
have been calculated. They are very closely related to
transition probabilities, which have been evaluated by the more
reliable
numerical integration using a suitable potential. In each electronic
state,
wave functions are computed for all
observed vibrational levels by numerical
solution of the radial Schrödinger equation in which the potential
energy
function
is calculated at equally spaced intervals of 0.01 Ǻ in the
range of nuclear separation range. The effect of high rotational
quantum
numbers on FC factors has been studied. The vibration-rotation
interaction (VRI)
on the FC factors of molecular
band systems is negligible for relatively low
rotational quantum numbers (J). Values
of FC factors and r-centroids are
given
for all allowed bands of each system, and the available band
wavelengths
are also entered in the respective tables.
Keywords: LaO, Franck-Condon factors, r-centroids.
ON THE STABILITY OF PLANETARY ORBITS WITH A MODIFIED HERMITE INTEGRATOR
OVIDIU C. FURDUI
Astronomical
Institute of the
Astronomical
Observatory Cluj-Napoca
Str.
Cireşilor
19, 400487 Cluj-Napoca, Romania
E-mail:
ovidiu.furdui@gmail.com
Abstract. We present
the results of very-long-term numerical integrations of planetary
orbital
motions over 1010 yr time including
all nine planets. A quick
inspection of our numerical data shows that the planetary motion, at
least in
our simple dynamical model,
seems to be quite stable even over this very long
time-span. A closer look at the lowest-frequency oscillations, using a
low-pass
filter, shows us the potentially diffusive character of the terrestrial
planets’
motion, especially that of Mercury. However, there are
no apparent secular
increases of eccentricity or inclination in any orbital elements of the
planets, which may be revealed by still
longer-term numerical integrations. We
have also performed a couple of trial integrations including the
motions of the
outer five
planets over the duration of 5×1010 yr.
Keywords: celestial mechanics – N-body problem – Solar System dynamics – stability.
LIBRATION POINTS IN FOCK’S RESTRICTED THREE-BODY PROBLEM
Vasile Mioc 1, Rodica Roman 2
Astronomical
Institute of the
Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania
E-mail:
vmioc@aira.astro.ro
Astronomical
Institute of the
Astronomical
Observatory Cluj-Napoca
Str.
Cireşilor
19, 400487 Cluj-Napoca, Romania
E-mail:
rroman@math.ubbcluj.ro
Abstract. We tackle the
circular restricted three-body problem within the
framework of Fock’s field, associated to a potential
of the form A1/r + A2/r2 + A3/r3
+ A4/r4. We
establish the equations of motion and prove the
existence of an analog of the Jacobian
first integral. After emphasizing some
features of the zero-relative-velocity surfaces, we approach the main
topic:
libration points.
As in the Newtonian case, there are three collinear libration
points, and, if they exist, two triangular libration points (situated
in the
orbital plane of the primaries). We give the expressions of the
positions of
all these points. If triangular points exist, they may not
form equilateral
triangles; the triangles are isosceles for equal masses of the
primaries, and
scalene else.
Key words: celestial mechanics – restricted three-body problem – libration points – Fock’s field.
BIELLIPTIC
TRANSFER WITH PLANE
CHANGES
MOHAMED ADEL
SHARAF
Department
of Astronomy, Faculty of Science,
80203
Jeddah,
Saudi Arabia
E-mail:
sharaf_adel@hotmail.com
Abstract. The
most powerful technique that has been devised for optimal plane change
maneuvers is known as the third-body
driven technique. This technique can be
viewed as classical bielliptic plane changes (or restricted
three-impulse plane
change)
with the apoapsis maneuver suppressed by the use of the third-body
forces. In the present paper, full analysis of the bielliptic
plane changes
maneuver (BPCM) is developed, as well as its importance as the basis of
the
third-body driven technique.
As to the computationally developments, we
established new formula to estimate the initial guess for the iterative
solutions
of the fundamental equations of BPCM. This formula not only secures
the convergence of the solutions, but also it could be
used to accelerate the
convergence. Finally, some numerical examples are included.
Key
words: astrodynamics – orbital transfer
maneuvers – trajectory
optimization.
DETERMINATION OF
A CELESTIAL
MOHAMED ADEL SHARAF
Department
of Astronomy, Faculty of Science,
80203
Jeddah,
Saudi Arabia
E-mail:
sharaf_adel@hotmail.com
Abstract. We develop a
general analytical method for the determination of
any celestial plane orientation of objects with respect to
a fundamental plane
at a certain epoch. This plane is defined as the plane of greatest
condensation
of these objects. The method is
applied for the determination of: the
equatorial coordinates of the galactic pole and the inclination of the Milky Way plane to the
celestial equator and the right ascension of its ascending node, all for the epoch 2000.0.
Key words: astrometry – ephemerides – galactic structure.
PRECISE
DETERMINATION OF MINOR
PLANET POSITIONS
GHEORGHE
BOCŞA1, MILCHO TSVETKOV2
1 Astronomical
Institute of the
Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania
E-mail:
gbocsa@aira.astro.ro
2 Institute
of Astronomy of the
72,
Tsarigradsko Shosse Blvd, 1784 Sofia, Bulgaria
E-mail:
milcho@skyarchive.org
Abstract. We
perform a first comparative study concerning position determination of
selected
minor planets observed in
Photographic observations were
made with the equatorial refractor (d
= 0.38 m, f = 6 m). The plates were
measured with a Carl-Zeiss
Ascorecord machine and digitized with an Epson
1640XL flatbed scanner. We compare manual measurements with data
processing of
digitized plates for five asteroids.
Key
words: astrometry – photographic
observations – digitization.
NEW LAWS
OF
PLANETARY DISTANCES
IVAN KOTLIAROV
Faculty
of Geography and Geoecology,
197101
Do Vostrebovaniya,
E-mail:
lrpg@mail.ru
Abstract. The
present paper gives a detailed analysis of the new formulation of
Titius-Bode
law by Poveda and Lara (2008) and
of the hypothesis that this law may exist in
extra-solar planetary systems. A thorough study of the correspondences
between
the
predicted distances and the observed ones in the Solar System and in 55
Cancri is given. A less known formula of planetary
distances – Butusov’s (1973)
law – is discussed. New predicted distances in 55 Cancri based on
Butusov’s law
are proposed.
Key words: Titius-Bode law – planetary systems.
FROM
SYNCHRONIZATION OF THE
ATOM TO
ORGANIZATION OF THE
UNIVERSE VIA GRAVITATION
GERD HELMECKE 1,
ULRICH HERKENRATH 2
1
Königstr. 4, D-53773
Hennef, Germany
E-mail:
dok-helmecke@t-online.de
2
Universität
Duisburg-Essen, FB Mathematik
Lotharstr.
65, D-47057
E-mail: ulrich.herkenrath@uni-due.de
Abstract. This paper is a contribution to develop a unified theory for
the basic
physical forces of nature. A model in the sense of a scientific
hypothesis is
designed, in which the gravitational force is explained as an
electromagnetic
effect. We take the following approach: the force,
which is called gravitation,
is effective between any masses, therefore between atoms, too. This
leads us to
the idea to study the interaction
of atoms in order to find causes for the
gravitational force, i.e., an attractive force between them. Since
electromagnetic forces are effective
on that scale, mass is equivalent to
energy, and general experience in physics recommends to try to explain
phenomena
with as few causes
as possible, we analyze the interaction of atoms under
electromagnetic aspects. Based on the hypothesis of a certain kind of
“synchronization”
of the atom and taking into account the electron sheath as a
rotating system of charges, we explain the attractive force between
atoms as an
electromagnetic effect. The explanation of gravitation, which we
present here,
together with basic cosmic laws presented in a previous paper
(Helmecke and
Herkenrath 2003), leads to important consequences for the understanding
of dark
matter, black holes and the evolution of the
Universe.
Key words: gravitation – unified theory – synchronization of the atom – dark matter – black holes – evolution of the Universe.