We report the discovery by the Swift hard X-ray monitor of the transient source Swift J2058.4+0516 (Sw J2058+05). Our multi-wavelength follow-up campaign uncovered a long-lived (duration >åisebox-0.5ex months), luminous X-ray (L $_X, iso$ ≈ 3 × …
GRB 070610 is a typical high-energy event with a duration of 5 s. Yet within the burst localization we detect a highly unusual X-ray and optical transient, Swift J195509.6+261406. We see high- amplitude X-ray and optical variability on very short …
Given the paucity of empirical constraints, the nature of the newly recognized phenomena called X-ray flashes (XRFs) has been an open question. However, with the recent detections of radio and X-ray afterglow it is finally possible to study the …