THE
BLAZHKO
EFFECT: 100 YEARS
AFTER

Vasile POP

Astronomical
Institute of the

Astronomical
Observatory Cluj-Napoca

Str.
Cireşilor
19, 400487 Cluj-Napoca, Romania

E-mail:
vpop@math.ubbcluj.ro

*Abstract*. This
paper attempts to provide an overview of the observational and
theoretical
status of the fascinating

long-term modulation of the pulsation of the RR Lyrae
stars. Out of the huge amount of literature connected with the

present subject,
I have selected the newest results.

*Key
words:* astrophysics
– RR Lyrae stars – Blazhko effect.

MULTI-SCALE STATISTICAL ANALYSIS OF THE SOLAR WIND PARAMETERS FLUCTUATIONS

NEDELIA ANTONIA
POPESCU^{ 1}, EMIL POPESCU^{ 1, 2}

^{1 }Astronomical
Institute of the

Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania

E-mail:
nedelia@aira.astro.ro

^{2 }Technical
University of Civil Engineering

Bd.
Lacul Tei 124, 020396

E-mail:
epopescu@utcb.ro

*Abstract*. Based on
time series of solar wind plasma and magnetic field data from Ulysses,
statistical methods of analysis are used

for the investigation of intermittent
comportment of solar wind and interplanetary magnetic field during
2001. Probability
distribution

functions and generalized structure functions method are applied
on the Ulysses/SWOOPS and VHM data, in order to study the

scaling of the solar
wind velocity and interplanetary magnetic field magnitude fluctuations,
at
different scales (time lags τ* _{n}*
=2

n = 0, 1, 2, ...7).

*Key
words:* solar physics – solar wind –
probability distribution function –
intermittent behaviour – interplanetary magnetic field fluctuations.

VELOCITY DETERMINATIONS FOR MAGNETOACOUSTIC SHOCK WAVES FROM SOHO/EIT IMAGES

ADRIAN SABIN POPESCU

Astronomical
Institute of the

Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania

E-mail:
sabinp@aira.astro.ro

*Abstract*. We use a new
multi-wavelength technique applied to the solar
corona SOHO/EIT images containing magnetoacoustic waves

(EIT waves). In this
way we constrain the wave phase velocity. We give, as well, some b-model
correlations with height for the vertical

extent of the wave. We apply them to
the particular EIT wave triggered by the eruptive event from

*Key words:* solar
corona – extreme ultraviolet – plasma
waves.

SEELIGER’S TWO-BODY PROBLEM (II): EQUILIBRIA

EMIL POPESCU^{ 1, 3}, DANIEL
PAŞCA^{ 2}, VASILE MIOC^{ 3}, NEDELIA
ANTONIA POPESCU^{ 3}

^{1 }Technical
University of Civil Engineering

Bd.
Lacul Tei 124, 020396

E-mail: epopescu@utcb.ro

^{ }

^{2 }University
of

Str.
Universităţii 1, 410087 Oradea, Romania

E-mail:
dpasca@uoradea.ro

^{ }

^{3 }Astronomical
Institute of the

Str.
Cuţitul
de Argint 5, 040557 Bucharest, Romania

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

*Abstract*. We
offer a deeper insight into the two-body problem associated to the
potential
proposed by Hugo Seeliger at the end of 1800s.

Our goal is now to find the
equilibria of the corresponding central-force problem. First, we resort
to
McGehee-type transformations to write

the motion equations and the first
integrals of energy and angular momentum. Then we search for
equilibria, taking
into account the whole

interplay among the parameter *A* of the field, the
constant *K*
of the field, and the integration constants of energy (*h*)
and angular momentum (*C*).

We find the number of equilibria for each such situation, and we locate
them
via their distances from the central body. An important issue is that

the
positions of the equilibria do not depend on *A*; they
are completely determined by the values of the two
integration constants *h* and *C*

(*K*
being a defining constant).

*Key
words:*
celestial mechanics – two-body problem – Seeliger’s theory of
gravitation –
equilibria.

MANEV POTENTIAL AND SATELLITE ORBITS

IOANNIS
IRAKLIS HARANAS^{ 1}, VASILE
MIOC^{ 2}

^{1 }Department
of Physics and Astronomy,

E-mail:
ioannis@yorku.ca

^{2 }Astronomical
Institute of the

Str.
Cuţitul de
Argint 5, 040557 Bucharest, Romania

E-mail:
vmioc@aira.astro.ro

*Abstract*. A good
description for various physical, astrophysical and
astronomical problems can be obtained by employing a Manev-type

of
gravitational potential, which was first introduced by Manev as a
classical
alternative to the theory of relativity, and allows for the same

motion of the
perihelion as general relativity does. The goal of this paper is to
demonstrate
Kaula’s important results for the derivation of

perturbing potentials as
functions of the orbital elements, used in satellite orbital theory in
the case
of such a potential. We achieve this using

Lagrange’s planetary equations, once
the disturbing potential that corresponds to Manev correction has been
converted to a function of the

orbital elements. Second we derive the changes
of the satellite orbital elements and compare them with the existing
general
relativistic expressions,

and also with those of parameterized post-Newtonian
gravity.

*Key
words:* celestial mechanics – satellite
dynamics – Manev field – Kaula’s
theory – relativistic effects.

THE
ROMANIAN ASTRONOMICAL
OBSERVATORY OF

Vasile POP^{ 1}, Ovidiu
FURDUI^{1}, VASILE MIOC^{ 2}

^{1 }Astronomical
Institute of the

Astronomical
Observatory Cluj-Napoca

Str.
Cireşilor
19, 400487 Cluj-Napoca, Romania

E-mail:
vpop@math.ubbcluj.ro , ovidiu.furdui@gmail.com

^{2 }Astronomical
Institute of the

Str.
Cuţitul de
Argint 5, 040557 Bucharest,
Romania

E-mail:
vmioc@aira.astro.ro

*Abstract*. We present the
history of the Cluj-Napoca
Astronomical
Observatory, from foundation to actual endowment and activity.

We also survey
the characteristic astronomical researches undertaken in this
observatory, and
the most significant persons who
worked

and work here. The paper is intended to
emphasize the role of the Cluj-Napoca
Astronomical Observatory in the Romanian astronomical

life at its 90th
anniversary.

*Key
words:* history of Astronomy –
astronomical observatories.