On the transit of Venus 2012: Method of computation for prediction of contact timings

Abstract

Transit of Venus over the solar disc is an extremely rare event. The phenomenon occurred last time on June 8, 2004 when the entire event was visible from all parts of India. Another Transit of Venus is going to occur on June 6, 2012, though the entire event will not be visible from India. The Positional Astronomy Centre publishes data on Transit of Mercury and Venus in its annual publication ‘The Indian Astronomical Ephemeris’. In this paper an attempt has been made to provide documentation on the methodology for computation of contact timings of the event. Using the methodology, the geocentric contact timings and local contact timings for important places of India for the event of Transit of Venus of June 6, 2012 have been predicted. The result thus obtained for different geocentric phases of the event has been compared with the predicted timings published by The Nautical Almanac Office, United States Naval Observatory and NASA.