The Sun

Monitoring of Active Physical Processes and Waves in the Upper Layers of the Solar Atmosphere on the Basis of Observational with High Dispersion Spectrograph and Field Observations of the Solar Eclipses

Head of the Project:  Vazha Kulijanishvili,

Scientific Group: V. Kulijanishvili (PhD), E. Khutsishvili (PhD), V. Kakhiani (PhD), T.Kvernadze (Doctorant), D.Khutsishvili (Doctorant), R.Apriamashvili (Observer, Young Researcher).

Project Summary:

It is well known that the solar corona is an extremely hot (about 2 million K), highly ionized gas surrounding the Sun and extending out at several solar radii, displaying streamers, plumes, and bubbles or loops.  At this time, the nature of the coronal emission lines in the visible, as well as in the Ultraviolet and X-ray are very well studied. They permitted important advances in our understanding of the 3D structure and physical conditions in the solar corona and their variations with phase of the solarcycle. Nevertheless, many uncertainties, such as the magnitude of the polarization degree, deviations of the polarization plane from its radial direction, corona heating and solar wind acceleration, still remain to be resolved.

The main objectives of the project are:

  • Monitoring of cyclical variation of polarization parameters (temperature and density) in the middle and outer solar corona:
  • Monitoring of the waves behavior in the solar corona: a possible key to the corona heating mechanism and acceleration of solar wind particles

 Each objective includes an observational as well as a theoretical study of the problem.

For solving the first task, we propose to study the coronal polarization parameters (temperature and density) and their variations with the phase of solar activity circle by the statistical re-analyses of our early polarization observations uniformity data obtained during the past six  total solar eclipses (1994, November 3, Brazil; 1995, October 24, India; 1997, March 9, Russia; 1999, August 11, Turkey; 2001, July 21, Africa; 2006, March 29, Egypt).

In order to solve the second task of the present project, we propose to study the emission line’s broadening, as well as the half-width changing on various altitudes in the different layers of the upper solar atmosphere. For different heights and different parts of the solar chromosphere and corona, we are going to make the CCD time sequence spectroscopic observations of the emission spectral lines of these layers. We will use a big non-eclipse coronagraph (D=530 mm, F=8000 mm) equipped with high-dispersion spectrograph, as well as Lyot-type small (D=115 mm, F=3000 mm) coronagraph.

The main goal of the Project is to search for a possible key to the enigma of corona heating mechanism and acceleration of solar wind particles. It is necessary:

  • to study the cyclical variations of the polarization parameters of the solar corona;
  • to study the nature of waves and oscillations in the solar chromosphere and corona;
  • to search for observational evidence of wave propagation in the upper layers of the solar atmosphere through spectroscopic observations of the spectral lines;
  • to determine the waves spatial distribution, damping time, wavelength, etc.;
  • to study the thermal motion of coronal electrons from the continuous spectrum of the electron-scattering corona;
  • to study the changes of the chromospheric and coronal emission lines half-width with the height.

The scheduled project activities include experimental and research objectives. The solution of these objectives will make the important contribution into the investigation of corona physics. The project activities provide the opportunity of more detailed research of the physical nature and structural features of the solar corona in connection to the solar activity. It will help scientific staff to integrate into international scientific unions and to collaborate with the leading institutes of the world.

The results of this project can be of importance for solving the problem of coronal heating, solar wind acceleration and space weather prediction. In particular, high frequency waves can be responsible for coronal heating and can provide the energy required for the solar wind acceleration. Moreover, waves and oscillations have the potential of being used in the prediction of active events (solar flares and CMEs) and consequently in space weather applications. Moreover, long-term variations of solar activity can facilitate the modeling of global temperature changes on the Earth.

Grants:  1). International Association for the Promotion of Cooperation with Scientist from the Independent States of the Former Soviet Union (INTAS), No 97-31198; 2). GNSF/ST07/4-189; 3). Grant of President of Georgia, PG/22/6-310/12; 4). Grant of Shota Rustaveli Science Foundation, FR/417/6-310/13.

International  Cooperation: Space Research Institute of the Austrian Academy of Scinces; Belgian KU Leuven – University;  Istanbul State University;  Institute of the Terrestrial Magnetizm, Ionosphere and Propagation of the Radio Waves of Academy of Sciences of Russion (IZMIRAN);

A big non-eclipse coronagraph of Abastumani Astrophysical Observatory
A big non-eclipse coronagraph of Abastumani Astrophysical Observatory

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