sideranautae said:
Did the "failed cores" have a rocky cores like this article suggests? I don't remember.
They were big worlds with massive atmospheres, but they weren't gas giants. So yes.
At the same time, there's also this... http://www.eurekalert.org/pub_releases/2014-06/hcfa-afa053014.php
So, Gas Dwarfs and MegaEarths.