OccultWatcher is a Windows program that helps astronomical occultation observers to stay tuned with the incoming events by tracking the asteroidal occultation predictions published and regularly updated in various sources called feeds. OccultWatcher searches the feeds you have subscribed for, for events that match your specified distance, star magnitude, event duration and other filter criterias. It allows you to announce your intentions to observe an event to all other observers around the world and helps the cooridnation in a global scale. At the time of the release of verion 3.2 there are more than 400 registered accounts (of people that announce their observing intentions) and more than 1500 known installations. The account registration and usage as well as the OccultWatcher software are absolutely free.

The following prediction feeds are currently available for subscription:

Feed Name	Description
IOTA Updates	Steve Preston's predictions from www.asteroidoccultation.com. The published predictions are for higher probability events and are computed using recent highly accurate astrometric data. They are generally with very good accuracy, higher probability and small error.
OZNZ	OZNZ (pronounced oz-noz) Extras are published by Dave Gault. These are low probability small asteroid events for the South-East Australia and New Zealand regions.
NAmer	North America low probability asteroid occultations calculated using Occult C# by Brad Timerson.
E.A.O.N.	The E.A.O.N. low probability events for the Europe region are maintained by Emmanuel Thienpont and formerly by Jean Schwaenen.
NALowMag	North America events of 50km+ asteroids with combined stellar and asteroid magnitudes of near 11 to not less than 12.9. Many of these have a magnitude drop <1. Maintained by Steve Messner.
TT14	Trans-Tasman events involving asteroids bigger than 50km, magnitude drop larger than 0.2 sec, duration longer than 10 sec, stars up to mag 14. Maintained by Dave Gault, Australia.
TNO	TNO Extras is a list of asteroid predictions involving Trans Neptunian Objects and stars brighter than mag 15. The search is conducted using OccultV4, the latest astorb and NOMAD. Since May 2010 the feed also includes predictions computed by Bruno Sicardi and the Rio Team. The feed is maintained by Dave Gault, Australia
SatWatcher	SatWatcher is a list of occultations and ecplises involving the satellites of Jupiter, Saturn and Uranus. The feed is maintained by Hristo Pavlov, Australia.

With the release of version 3.2 there is one new feed called "Planned Observations". This feed contains all events that someone has already announced a station for. This way even if you are not particularly interested in the events of an existing feed, if there is an event that comes close to you and matches your filter criterias and if there is at least one announced station for it, OW will show it as "Planned Observation". This way events that are going to be attempted by an observer could get more observations.

With its enhanced alerts and reminders OccultWatcher can be also very helpful for tracking your personal asteroidal occultation predictions generated using prediction software such as Occult and LinOccult. It provides extra and very detailed information for all predictions including parameters of the star and asteroid, information about double asteroids, historical observations data and others. The software comes with a function to draw star charts using the free planetarium program C2A developed by Philippe Devechere in France and which supports the star catalogues: Hypparcos, Tycho2, UCAC2, NOMAD. OccultWatcher also provides ability to be extended by your own Add-ins written using Microsoft.NET

If you are new to asteroidal occultations here are some online resources you would find most useful:

• IOTA - International Occultation Timing Association
• IOTA Yahoo Group
• Euraster - a website for Asteroidal Occultation Observers in Europe
• RASNZ OccSec - Australia/New Zealand Occultation Observers Information
• Occult - Software for Windows for predictions of asteroidal occultations and many other astronomical phenomenas by Dave Herald
• LinOccult - Software for Linux for asteroidal occultation predictions by Andrey Plekhanov
• IOTA Updates - High accuracy asteroidal occultation predictions by Steve Preston. Those are also available in OccultWatcher as a prediction feed

Software Requirements for running OccultWatcher:

• Windows 98 or later. Works best on Windows XP Professional and Windows Vista (32 or 64 bit)
• Microsoft.NET Framework 2.0 or later

Hardware Requirements: Anything that can run the required software.

Internet Connection Requirements: In other to receive information about the predictions from the online feeds you need an internet connection. There is no particular requirement for the speed of your connection, but as a general rule OccultWatcher will do well so long as your connection allows you to view maps using GoogleMaps without too much delays.