The variability of Delta Cephei was discovered in 1784 by astronomer John Goodricke
. Goodricke lost his hearing after falling ill at age 5, but he received a solid education in mathematics and natural philosopy nonethless.
On this occasion, a day trip to Jodrell Bank was arranged with a second day based in York, with visits to the historic Observatory near the city centre (conducted by Martin Lunn), York Minster and to the location of the Treasurer's House, from where John Goodricke
first observed and discovered the variability of the stars Algol and 8 Cephei.
In 1782 Algol was studied by a British astronomer, John Goodricke
(1764-1786), a deaf-mute.
discovered and tracked Delta's periodic variations in 1784; he speculated that they might be caused by dark marks on the star rotating in and out of view.
It varies from magnitude 3.3 to 4.3 with a period of 12.94 days--up from 12.89 days in 1784, when John Goodricke
discovered its variations.
Its changes are obvious to the naked eye, but there is no good evidence that anyone ever noticed them before John Goodricke
discovered Algol's variability in 1782.
Argelander's variable-star work with his star cataloging and overlooks earlier work by John Goodricke
, Edward Piggott, William Herschel, and others.
(That star's fluctuations were first detected in 1784 by English amateur John Goodricke
, another great pioneer of variable-star astronomy.)
Named in honor of the 18th-century English amateur astronomers John Goodricke
and Edward Pigott, the facility is equipped with a Celestron 14-inch f/11 Schmidt-Cassegrain reflector and a homemade CCD camera that originally featured a high-efficiency SITe chip with a 512-pixel-square array.
Collaborating with Pigott was John Goodricke
, also in York, who was only 17 years old.
Beta Lyrae's period has been increasing gradually from 12.89 days, when first measured by John Goodricke
in 1784, to 12.93784 days in 1993, according to the ephemerides of eclipsing binaries issued annually by Cracow Observatory in Poland.