November 2006: The H.E.S.S. experiment discovers a cosmic timekeeper - the first observation of periodic very high energy gamma ray emission (Astronomy & Astrophysics 460, Nov. 26, 2006, preprint, H.E.S.S. press release, see also MPG, PPARC) )
October 2006: H.E.S.S. discovers drastic variations of very-high-energy gamma rays from the central engine of the radio galaxy M87 (Science Express, Oct. 26, 2006, H.E.S.S. press release, see also MPG ( E, D), Univ. Heidelberg (E, D) , link to reprint under H.E.S.S. journal publications)
April 2006: Measurements of two distant quasars by H.E.S.S. reveal that intergalactic space is more transparent to gamma-rays than previously thought (Nature 440 (2006) 1018-1021, preprint, H.E.S.S. press release, see also MPG, CNRS, PPARC)
February. 06: H.E.S.S. detects gamma-ray afterglow from Galactic Centre gas clouds, indicative a of pre-historic particle accelerator (Nature 439 (2006) 695, H.E.S.S. press release, see also MPG, CNRS, PPARC)