Reply To: Understanding Timings used in the Journal

Forums General Discussion Understanding Timings used in the Journal Reply To: Understanding Timings used in the Journal

Tim Haymes

The occultation times in the table on page 337 are for an observer at Greenwich. See the HBAA page 39 and note under the table. Why the 0.1 minute precision? Well this is the format (as suggested by David) that is produced by Occult4 software. There is a routine that produced the tabulated data used by the Handbook. This format is historical, and goes back to the 1960s, but a good summary for two stations.

Predicted times can be computed to better than 1 sec if the observer coordinates are used in the software, so the tabulated times are only a guide. For other locations the times will differ by up to 2 minutes depending on how far the observer is from Greenwich.

Im grateful to Nick Hewitt for including Lunar prediction on his Sky Notes page. I find them fascinating to observe. The Lunar Section Circular contains predictions to 8th magnitude for those seeking more opportunities. The time format for these are dd hh mm ss.s for a single station – again a guide only.

I offer a service to keen occultation observers. In that i can produce predictions to 1 sec precision for their site via email.

Tim –
Lunar Section.

  • This reply was modified 7 months, 3 weeks ago by Tim Haymes.