TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5262 SUBJECT: The Unusually Long-Lived Afterglow of GRB 060614 DATE: 06/06/15 17:31:08 GMT FROM: Peter Brown at PSU The Unusually Long-Lived Afterglow of GRB 060614 P. J. Brown (Penn State), S. T. Holland (NASA/GSFC & USRA), V. Mangano (INAF-IASFPA), A. M. Parsons (NASA/GSFC), & N. Gehrels (NASA/GSFC) report on behalf of the Swift Team: Swift/UVOT observations of the optical afterglow of GRB 060614 (trigger=214805; Parsons et al. GCN 5252) show that the V-band light from the afterglow remains approximately constant at V ~ 19.8 until at least 80,000 s after the BAT trigger (the latest data presently available). Similar behaviour is seen in the B-, U-, and UVW1-bands. There is weak evidence that the UVM2 and UVW2 fluxes decrease after approximately 10,000 s. The UV-optical colors are similar to GRB060218/SN2006aj, whose shock breakout peaked at about 40,000 s in the UV and optical and then began fading before being overtaken by the rising SN (Campana et al. Nature, in press, astro-ph/0603279). Though we do not see as prominent of a rise in the UVOT data for GRB060614, other observers have noted rising and fading in the R band (Schmidt, Peterson, & Lewis GCN 5258; French et al. GCN 5257), and Malesani et al. (GCN 5261) have also noted the similarity to GRB060218. The BAT lightcurve of GRB 060614 (Barthelmy et al. GCN 5256) shows a hard, bright initial flare followed by softer, extended prompt emission. The T90 duration of the prompt emission was 108 s. The prompt fluence was the greatest of all Swifts burst that have been located by the BAT. The X-ray light curve (Mangano et al. GCN 5254) was unusually bright and decayed rapidly with a strong hard to soft evolution. This was followed by an extended period of near-constant emission, that shows evidence for small-scale flares, out to approximately 70,000 s. The hardness ratio of the flat part of the light curve is nearly constant, and the power law fit of the spectrum gives a standard afterglow photon index of 1.8 with no absorption in excess the Galactic N_H. In light of the peculiar characteristics observed by all three Swift instruments and ground based observers, we encourage further observations of this unusual afterglow.