Is there any way a planet could form independent of a star?

I just recently heard that there are currently no theoretical models that support planet formation without a star, but I can't remember where. So, I thought I would request all of your expertises. Thank you much. I wanted to confirm whether this is true or not and to know if there are any theories that could account for planet formation in interstellar or intergalactic space.

• What is your question? That you don't believe that theoretical models say this? – Rory Alsop Mar 13 '15 at 11:03

At present there are plenty of candidate "free-floating planetary mass" objects. For example see Joergens et al. (2014); Liu et al. (2013); Zapatero-Osorio et al. (2000). Unless we have our understanding of the physics completely wrong, then it is likely that at least some of these are lower than 13 Jupiter masses. However, their origin remains unclear. It is possible they could all have formed around stars and then subsequently been ejected, but the presence of significant numbers of these objects in young star forming regions and the lack of $\sim$10 Jupiter-mass objects orbiting stars, suggests that there is an alternative formation scenario that can produce such objects in isolation.