Hunting for binary Cepheids using lucky imaging technique
  Detecting companions to Cepheids is difficult. In most cases the bright pulsator overshines the fainter secondary. Since Cepheids play a key role in determining the cosmic distance scale it is crucial to find binaries among the calibrating stars of the period-luminosity relation. Here we present an ongoing observing project of searching for faint and close companions of Galactic Cepheids using lucky imaging technique. 
P. Klagyivik, L. Szabados, A. Szing, Zs. Reg\'aly
astro-ph.SR