
TY  - JOUR
A1  - Bray, RJ 
A1  - Loughhead, RE 
T1  - The Lifetime of Sunspot Penumbra Filaments
JF  - Australian Journal of Physics
JO  - Aust. J.  Phys.
Y1  - 1958
VL  - 11
IS  - 2
SP  - 185
EP  - 190
KW  - 
UR  - https://doi.org/10.1071/PH580185 
N2  - Twenty-seven photographs of a sunspot showing a particularly distinct filamentary structure are analysed in order to obtain an estimate of the lifetime of the penumbral filaments. The photographs have been selected from some 2400 taken over a period of 5 hr. Although the measurements are rendered somewhat uncertain by observational difficulties the results clearly indicate that some filaments remain identifiable for periods of the order of hours. 
ER  -

