I think that was supposed to be an Iron tail, I remember seeing something about that a month or 2 ago.
I recorded a straight ion tail on a few of my images, which may have been a Sodium tail at one stage around mid January, as it was quite red in colour, but a regular ion tail later as it appeared more blue in colour.
http://www.ozemail.com.au/~loomberah/mcnaught.htm
Gordon