The Hubble Deep Field North reveals a supernova at z~0.95

Abstract

We report the discovery of a variable object in the Hubble Deep Field North (HDF-N) which brightened, during the 8.5d sampled by the data, by more than 0.9mag in I_814 and about 0.7mag in V_606, remaining stable in B_450. Subsequent observations of the HDF-N show that two years later this object has dimmed to about its original brightness in I_814. The colours of this object, its brightness, its time behaviour in the various filters and the evolution of its morphology are consistent with it being a Type Ib supernova in a faint galaxy at z.