What is a Google News Sitemap?
A Google News Sitemap is a sitemap used to assist Google in the indexing of Google News specific content.
A Google News Sitemap should only contain resources that adhere to the various Google News guidelines.
News articles in news sitemaps should not be older than two days.
Sitemaps can contain up to 1,000 items.
If there are more than 1,000 articles you can use a sitemap index file and use multiple sitemaps.