Bibcode
DOI
Hirzberger, J.; Bonet, J. A.; Vázquez, M.; Hanslmeier, A.
Bibliographical reference
The Astrophysical Journal, Volume 527, Issue 1, pp. 405-414.
Advertised on:
12
1999
Journal
Citations
31
Refereed citations
26
Description
The evolution of exploding granules is studied by using a spatially as
well as temporally highly resolved time series of white-light images of
80 minute duration. The results of this study show that the dynamics of
exploding granules is strongly affected by their surroundings and that
their appearance is closely related to the mesogranular flow field.
Comparing the behavior of exploding granules with that of smaller dark
structures-so-called dark dots-and with the results of model simulations
leads to the conclusion that both phenomena, as well as a third newly
found phenomenon (dark structures occurring in the centers of granules
that are approximately twice as large as dark dots but smaller than
typical centers of exploding granules) are different types of strong
downflows developing in the centers of granules. The motions of all
these three phenomena-the expansion of exploding granules and the proper
motions of the smaller dark structures, respectively-can reach
velocities close to the sound speed in the solar photosphere. Another
type of structure-narrow intergranular connections between granules-has
also been studied. Our results show that these structures are real solar
phenomena and are not caused by a variation of the image quality.
Therefore, in following and describing their evolution, we try to find
an explanation for their frequent occurrence.