Jerry Spevak (Double Stars at the Limits of Perception) is an experienced observer and astronomy writer whose articles and photographs have appeared in Astronomy and Deep Sky magazines.

Based on two years of observations with his Pronto and using data from the Hipparcos satellite mission, Jerry has created a new resolution criterion. For decades, observers have defined the performance of their telescopes by the Dawes limit, but Jerry has found that doubles can be detected far below this value. Recently his result has been published in The Observatory, a British peer-reviewed astronomy journal.