  In this letter we have analyzed the temporal correlations of the
angle-of-arrival fluctuations of stellar images. Experimentally measured data
were carefully examined by implementing multifractal detrended fluctuation
analysis. This algorithm is able to discriminate the presence of fractal and
multifractal structures in recorded time sequences. We have confirmed that
turbulence-degraded stellar wavefronts are compatible with a long-memory
correlated monofractal process. This experimental result is quite significant
for the accurate comprehension and modeling of the atmospheric turbulence
effects on the stellar images. It can also be of great utility within the
adaptive optics field.
