Only two so-called Iron stars exist: XX Oph and AS 325. XX Oph was first observed in 1924 by Merrill. He noted strong, doubly ionized iron emission lines were present in the spectra, thus the name iron star. AS325 was noted to be a similar type object by Howell and Bopp (1982). Further observations of both stars have led to the development of a model (Cool et al., 2005) for both stars which explains the optical emission lines and that the stars consist of two separate stars, possibly in a binary.
The current model has each Iron Star composed of a Be star and a late type (supergiant) companion separated by 1-2 thousand AU. The the interaction of the Be wind with the mass loss from the red star and the dust/gas remnant cocoon surrounding them both. We plan to use Spitzer to observe the dust environment in the star AS325.