Period-brightness relationship in chromospheric bright points

Abstract

Chromospheric bright points are sites where intense heating takes place by 3-min period waves. A 35-min-long time series of photographic spectra obtained in CaII H-line on a quiet region at the center of the solar disk under high spatial, spectral, and temporal resolution at the Vacuum Tower Telescope (VTT) of the Sacramento Peak Observatory has been analyzed to show that the period of intensity oscillations associated with bright points in the interior of the supergranular cells is independent of their intensity enhancements. We find evidence for a constant period of oscillations in bright points, independent of their peak brightness, and different from the period of network oscillations. This suggests that the heating mechanism may be identical (by 3-min period waves) in any class of bright points while in the case of network elements it may be an entirely different mechanism (by 5-7 min period waves). In addition, it is shown that the amplitudes of the main and the follower pulses of bright points decay exponentially with time and the decay rate is constant with their brightness in any class of bright points