Edward was already interested in variable stars, and he gave Goodricke a list of those that he thought were worthy of observation.

Goodricke is credited with discovering the periodic variation of β Lyrae[2] and δ Cephei, the prototypical example of the Cepheid variable stars.

[3] Although several stars were already known to vary in apparent magnitude, Goodricke was the first to propose a mechanism to account for this.

In 1949, Sidney Melmore[6] showed that Goodricke worked from the Treasurer's House (now owned by the National Trust) very near York Minster, and concluded that he had observed from the north window of the top floor of the south-east wing, looking south towards the Minster.

However, records indicate that the Goodricke family had rented rooms from Edward Topham, the then owner of the northwest wing of the house.