I would probably call this a News ticker.

I think it fits very nicely with the case you've described. On the left hand side you've got longer news articles and posts. The column on the right has shorter, brief news. Facebook

Facebook uses the term Ticker for the brief news that are displayed on the right side of the screen in the desktop version.

Wikipedia has some explanation of the term news ticker and where is originates from. Quoting from there:

A news ticker [...] resides in the lower third of the television screen space on television news networks dedicated to presenting headlines or minor pieces of news. It may also refer to a long, thin scoreboard-style display seen around the front of some offices or public buildings.

[...]

Since the growth in usage of the World Wide Web, news tickers have largely syndicated news posts from the websites of the broadcasting services which produce the broadcasts.

I would probably call this a News ticker.

I think it fits very nicely with the case you describe. On the left hand side you've got longer news articles and posts. The column on the right has shorter, brief news.

Facebook uses the term 'Ticker' for the brief news that are displayed on the right side of the screen in the desktop version. Basically all activity of friends is displayed there (at least as a teaser) while the news feed displays only important stories (but with some more detail) by default.

Wikipedia explains the term 'News ticker' and where is originates from. Quoting from there:

A news ticker [...] resides in the lower third of the television screen space on television news networks dedicated to presenting headlines or minor pieces of news. It may also refer to a long, thin scoreboard-style display seen around the front of some offices or public buildings.

[...]

Since the growth in usage of the World Wide Web, news tickers have largely syndicated news posts from the websites of the broadcasting services which produce the broadcasts.