A team of 12 staff and students travelled in three groups to locations west of Sligo on the evening of Tuesday 20 July, to observe with small telescopes and binoculars the predicted occultation of the magnitude 6.5 star HIP186 in Pisces by the D-type minor planet (773)Irmintraud (diameter c.95km), at approximately 01:19:22 UT on 21 July 2004. This was a particularly interesting event, as it had previously been suggested that Irmintraud could be an example of a very primitive parent body similar to the source of extremely rare, primitive meteorites such as Tagish Lake.
Despite unfavourable weather the Armagh team was the only group on the island of Ireland able to observe the star and report a definite negative observation. Similar negative results were reported by observers in Spain, Italy and France, suggesting that the asteroid was quite far from its predicted path. This was a valuable learning experience for the Armagh occultation team, and it gave the Armagh Observatory summer students the opportunity to experience the development of a real scientific project from inception to completion, culminating in a short publication.