Leonids 2009

This year may produce another enhanced return of the Leonid meteor shower, with ZHR hourly rates expected to exceed 150+ according to independent studies by Jérémie Vaubaillon, Mikhail Maslov, Esko Lyytinen, Danielle Moser, David Asher, Mikiya Sato and their respective collaborators (click the links for details). The main peak(s) are expected to occur in the night of November 17 to 18 around 22h00 UT (= 17h00 US Eastern, 23h00 Central Europe, 3h30 India, 6h00 Beijing), although variable activity may happen at almost any stage between November 16 and 18. Continuous monitoring is necessary. Leonids are generally only visible after local midnight from any longitude, with the exception of some long Earth-grazing Leonids before midnight when the radiant is still very low. Consult the shower calendar for more background.

Scientists depend strongly on visual observations by volunteers to test the theoretical models and improve future predictions.
For more information on contributing your own observations, please consult the observing instructions and the instructions for filing a report. The IMO offers an electronic report form to submit your observations,
and will automatically include them in the ZHR activity graph shown on the right.

Important note for visual observers: to allow for detailed analysis, please report the Leonid activity in short intervals. Try to avoid more than 5 to 10 Leonids per interval, and in any case avoid intervals longer than 10-15 minutes throughout November 17. Even when the rate is poor due to low radiant elevation or bad weather; the few meteors that you see may be part of an outburst and the exact time of their occurrence helps to determine the outburst time. Note that you can customize the number of rows in the report form or simply submit multiple forms.

Contact for observers in China with translation problems: 亚洲的观测者： 如果你有任何的问题，请联系 gba@arm.ac.uk。邮 件可以使用中文。