We present a rigorous approach to the problem of the random clustering of points in one-dimensional Poissonian distributions. Exact expressions for the probability density of clusters are derived, and the statistical properties of the inner configuration of their associated structures are studied in detail. We review previous works in the field

The paper analyzes white-light images of solar granulation taken outside active regions, at regular intervals along the polar axis and the equator, in order to study its center-to-limb variation and possible changes with the solar latitude. The 2D spatial power spectra of the brightness distribution are calculated and corrected for the distortions

Not Available

We have compiled all the available optical B band data on OJ287, between 1890 and 1991. Using this data we have found a period of 11.6 +/- 0.5 yr for the outbursts in OJ 287. This value is in good agreement with the period of 11.65 yr between outbursts and 11.05 yr between minima found previously by Sillanpaa et al. (1988), using V-band data. Based

Not Available