Sounds like a planet in the process of forming. Maybe it broke up and coalesced again. After all, we really don’t have a clear idea of how long these things take.
The impact theory of our moon suggests that it formed within a year or so.
Is Planet X a hoax? (Nibiru)
Probably this Fomalhaut b exoplanet is reabsorbing material is shed in an impact or other event, or is absorbing material from other events in that system.
Regarding the impact model for lunar formation:
http://www.freerepublic.com/focus/chat/1234919/posts?page=10#10
http://www.freerepublic.com/focus/chat/2568513/posts?page=29#29
http://www.freerepublic.com/focus/bloggers/2639823/posts?page=51#51
some sidebars:
http://www.freerepublic.com/focus/news/986454/posts
http://www.freerepublic.com/focus/chat/1203912/posts
http://www.freerepublic.com/focus/chat/1216757/posts
http://www.freerepublic.com/focus/bloggers/1250694/posts
http://www.freerepublic.com/focus/chat/1294934/posts
http://www.freerepublic.com/focus/chat/1309193/posts
http://www.freerepublic.com/focus/news/1665706/posts
http://www.freerepublic.com/focus/chat/1725156/posts?page=42#42
http://www.freerepublic.com/focus/news/1792228/posts
http://www.freerepublic.com/focus/news/1798620/posts
http://www.freerepublic.com/focus/news/1885157/posts
http://www.freerepublic.com/focus/chat/2040344/posts
http://www.freerepublic.com/focus/chat/2044222/posts
http://www.freerepublic.com/focus/news/2056679/posts
http://www.freerepublic.com/focus/chat/2070597/posts
http://www.freerepublic.com/focus/chat/2440664/posts
http://www.freerepublic.com/focus/chat/2614509/posts
http://www.freerepublic.com/focus/chat/2614513/posts
http://www.freerepublic.com/focus/chat/2725717/posts
http://www.freerepublic.com/focus/chat/2753599/posts
http://www.freerepublic.com/focus/chat/2753883/posts
http://www.freerepublic.com/focus/chat/2758171/posts
http://www.freerepublic.com/focus/chat/2765214/posts
http://www.asa3.org/ASA/resources/Wiens.html