In 1977 he suggested that widely observable celestial events such as nova explosions may be used by hypothetical extraterrestrial intelligences for scheduling the transmission of signals. This would allow receivers in other stellar systems to estimate when the signals would arrive. To test this concept, during a six-month period in 1988, the star Epsilon Eridani was observed using a 40-foot radio telescope at the National Radio Astronomy Observatory in Green Bank, West Virginia, with Nova Cygni 1975 being used as the timer. However, no anomalous radio signals were observed. This does not, of course, preclude the idea from being confirmed at a later date.
