Subaru optical observations of the two middle-aged pulsars PSR B0656+14 and Geminga Y. A. Shibanov, S. V. Zharikov, V. N. Komarova, N. Kawai, Y. Urata, A. B. Koptsevich, V. V. Sokolov, S. Shibata and N. Shibazaki A&A, 448 1 (2006) 313-326 Published online: 17 February 2006 DOI: 10.1051/0004-6361:20054178