
TY  - JOUR
A1  - Bray, RJ 
A1  - Loughhead, RE 
T1  - High Resolution Observations of the Granular Structure of Sunspot Umbrae
JF  - Australian Journal of Physics
JO  - Aust. J.  Phys.
Y1  - 1959
VL  - 12
IS  - 4
SP  - 320
EP  - 326
KW  - 
UR  - https://doi.org/10.1071/PH590320 
N2  - High resolution photographs of sunspot umbrae have confirmed the existence of an umbral granulation, resembling the photospheric granulation but differing in regard to lifetime and cell size. Bright structures in the form of " loops" are also seen. Quite apart from the granulation, the intensity contours of spot umbrae show a detailed and complex structure. 
ER  -

