Alerts are expected to be discovered and published to the world within \(\sim\)24-48 hours of observation by the satellite. The Alert Stream will go live once Gaia has mapped at least 10\(\%\) of the sky, a minimum of 3 times, which takes approximately one month (see Fig \ref{fig:scanning}). Once the Gaia alert stream is fully operational all alerts will be made publicly available, and thus accessible for use by the community in their dedicated followup campaigns (see Section \ref{followup}). During the commissioning, initialisation and early operations phase of Gaia (January - August 2014) - there will be systematic validation of the Gaia alerts, whereby the operational system will be assessed before going ‘Live’. The science alerts will be available to the community in web-based and email-based formats and will be produced in Virtual Observatory Event (VOEvent) - machine-readable format.
Each Alert package will consist of: coordinates, magnitudes, light curves, spectra, colours, proper motions, parallaxes (when available), astrophysical parameters (pars) (when available), features (random forest classifier see Section \ref{class}), classifier probabilities, cross match results.