Youth Astronomy Apprenticeship (YAA): An Initiative to Promote Science Learning Among Urban Youth and Their Communities
YouTube and political communication -- Macedonian case
YSO variability in Massive Star-forming Regions
YSOs candidates and knots in CrA cloud (Peterson+, 2011)
YSOs in L1630N and L1641 (Fang+, 2009)
yThe Mercury sodium atmospheric spectral imager for the MMO spacecraft of Bepi-Colombo
Yule analysis of sunspots and auroral phenomena
YY-Orionis stars - an interesting group of the T-Tauri stars