S Ori 70: Still a Strong Cluster Planet Candidate

In this paper I show that the coolest σOrionis cluster planet S Ori 70 is still a strong candidate member despite recent claims by Burgasser et al. that it could be a brown dwarf interloper. The main point of my argument is that the colors of S Ori 70 are significantly different to those of field dwarfs. This object has in fact the reddest H − K color of all known T dwarfs, a clear indication of low gravity according to all published models. In a J − H versus H − K diagram, S Ori 70 lies in the region where models of ultracool dwarfs predict that low gravity objects should be located. I conclude that S Ori 70 is still a strong candidate member of the σOrionis open cluster. I briefly discuss additional observational tests that can be carried out with existing facilities to verify the σOrionis membership of this cluster planet candidate.