By default the native RSS Viewer webpart in SharePoint is designed so that clicking the article title only serves to show or hide the article description.
As you will likely want Readers to open links in a new window, you will thus need to customise the webpart's setting by addinging target="_blank" into the XSL for the link.
The following guides may be helpful in achieving your set up:
RSS Viewer Customisation
Full source code for customized RSS Feed XSLT