We have searched for periodicities in our VRIJHK photometry of PKS 2155-304, which covers the years 2005-2012. A peak of the Fourier spectrum with high significance is found at T$\sim$315 days, confirming the recent findings by \cite{ Zhang2014}. The examination of the gamma-ray light curves from the\textit{ Fermi} archives yields a significant signal at $\sim$ 2T, which, while nominally significant, involves data spanning only $\sim$ 6T. Assuming a black hole mass of $10^{ 9}\ M_{ \odot}$ the Keplerian distance corresponding to the quasi-period T is $\sim10^{ 16}$ cm, about 50 Schwarzschild radii.
Categories: astro-ph.HE astro-ph.GA