Widgets have been removed from version 1.2.0 of the Stargazer theme. There’s no reason to panic though. The widgets are still available. You simply need to install and activate the Widgets Reloaded plugin: http://wordpress.org/plugins/widgets-reloaded
That plugin has the exact same widgets that were included in previous versions of the theme.
If you’re interested in knowing the “why” of this decision, please take a moment to read the following post.