SIMBAD references

We investigate the possibility that the expanding ring of gas surrounding the O star λ Ori could be due to the explosion of a type II supernova some 300,000-370,000 years ago. Based upon the observed properties of the ring and a set of simple equations describing the radius and expansion velocity of a supernova remnant as a function of time, we find that the expanding ring could be the result of a supernova occurring in a flattened molecular cloud. This model could explain the peculiar motion of λ Ori relative to the ring of gas if λ Ori were the binary companion to the progenitor star of the supernova.