37th DPS Meeting, 4-9 September 2005
Session 8 Motions of The Planets, Eclipses and Transits
HAD Oral, Monday, September 5, 2005, 2:00-3:30pm, Umney Theatre, Robinson College

[Previous] | [Session 8] | [Next]

[8.01] Credentialing Kepler: Transits in the Seventeenth Century

O. Gingerich (Harvard-Smithsonian CfA)

Kepler's successful prediction of the 1631 transit of Mercury spurred an interest in his decidedly user-unfriendly Rudolfine Tables. Because his Ephemerides went only to 1636, he did not draw attention to the 1639 transit of Venus, although the tables actually predicted the phenomenon, and the observation by Horrocks again proved the superiority of Kepler's work. By mid-century alternative user-friendly versions of the Rudolfine Tables were published by V. Renieri in Italy, J.B. Morin in France, Maria Cunitia in Germany, and (in a more modified form) by J. Shakerley in England. Transits of Mercury were observed in 1651 (by Shakerley in Surat, India), 1661, 1667, 1690, and 1697, giving astronomers opportunities to compare the predictions from these tables as well as those of Lansbergen (which were a variant of the Copernican Prutenic Tables).

Because of the subsequent interest in transits for determining the length of the astronomical unit, the 18th-century French astronomer J-N. Delisle compiled for these early transits extensive systematic records, which are now preserved at the Paris Observatory. By his day, however, the as-yet-unpublished tables of Edmond Halley gave the most successful predictions, and Delisle showed little interest in further credentialing the Rudolfine Tables, a process that had already taken place in the previous century.

[Previous] | [Session 8] | [Next]

Bulletin of the American Astronomical Society, 37 #3
© 2004. The American Astronomical Soceity.