\section{Alert Publication}

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.