  In a series of papers we have recently studied the clustering of LRG galaxies
in the latest spectroscopic SDSS data release, which has 75000 LRG galaxies
sampling 1.1 Gpc^3/h^3 to z=0.47. Here we focus on detecting a local maxima
shaped as a circular ring in the bidimensional galaxy correlation function
\xi(pi,sigma), separated in perpendicular \sigma and line-of-sight \pi
distances. We find a significant detection of such a peak at r ~110 Mpc/h. The
overall shape and location of the ring is consistent with it originating from
the recombination-epoch baryon acoustic oscillations (BAO). This agreement
provides support for the current understanding of how large scale structure
forms in the universe. We study the significance of such feature using large
mock galaxy simulations to provide accurate errorbars.
