Diagnostic of Coronal Bright Points

Lead Investigator:
K. Bocchialini (Institut d'Astrophysique Spatiale)

Team Members:
J.-C. Vial (Institut d'Astrophysique Spatiale)
Einaudi (University of Pisa)

Technical Summary:

Propagating waves are good candidates to provide energy and heat the corona. But to ascertain the viability of a wave theory of coronal heating, we still have to check if the energy is actually deposited by the travelling waves in the time interval corresponding to the crossing of the corona by the wave itself. The dissipation properties of MHD waves are governed by equations where the coefficients of dissipative terms are very small. Therefore the rate of dissipation of MHD waves is strongly related to the existence of small scales (Malara et al., 1992). These small scales are not observable, but could have signatures such as small and intermittent energetic bursts, like bright points. These elementary small magnetic structures (size between 10" and 30") can be observed in the network boundaries, in the quiet Sun or in coronal holes, and evolve on timescale of several minutes.

The aim of the program is to derive a diagnostic (Temperature, densities, etc) of the bright points using different lines formed a different altitudes, and ratios of lines sensitive to the temperature and density; the observing profiles will be compared with theoretical ones computed from the thermodynamical parameters provided by the numerical code developped at the University of Pisa. We are now performing a statistical study of bright points as a function of the energy, as it has been discussed in Einaudi et al. (1996).


Complete text of proposal.