TITLE: GCN CIRCULAR NUMBER: 7664 SUBJECT: GRB 080411: Continued Swift Monitoring DATE: 08/05/02 21:04:17 GMT FROM: Frank Marshall at GSFC F.E. Marshall (NASA/GSFC), O. Godet (U. Leicester) and S.R. Oates (MSSL-UCL) report on behalf of the Swift team: The XRT and UVOT instruments on Swift continue to detect GRB 080411 19 days after the BAT trigger (Marshall et al., GCN Circ. 7584). The X-ray light curve shows a broken power-law behaviour with breaks at about T+8 ks and T+240 ks and additional short-term features at late times. Since the latter break, the decay index has been 1.54 +/- 0.12, and the 0.6-10 keV flux at T+1600 ks was 1.3 x 10^-13 ergs/s/cm^2. The optical light curve also shows a similar broken power-law behaviour. At T+1600 ks the magnitude (uncorrected for Galactic extinction) in the broad-band white filter was 22.7 +/- 0.2 using the UVOT photometric system (Poole et al. MNRAS 383, 627 (2008)). Recently the decay index has been 1.30 +/- 0.03. Additional Swift observations of GRB 080411 are planned. Since the optical afterglow is approaching the sensitivity limit for UVOT, ground-based observations are encouraged. Please contact the Swift Burst Advocate for this burst at marshall AT milkyway.gsfc.nasa.gov if you desire additional information regarding the Swift followup of this burst.