D. A. Perley (UC Berkeley), J. S. Bloom (UCB), A. J. Levan (U. Warwick),
W. Li (UCB), N. R. Tanvir (U. Leicester), N. R. Butler (UCB), H-W. Chen
(U. Chicago), R. Chornock (UCB), J. X. Prochaska (UCO/Lick), C. D.
Bailyn (Yale), A. Bunker (U. Exeter), R. Chornock (UCB), B. Cobb (Yale),
P. B. Hall (York U.), A. V. Filippenko (UCB), N. Gehrels (NASA/GSFC), K.
Glazebrook (Swinburne), J. Granot (U. Hertfordshire), K. C. Hurley
(UCB), D. Kocevski (UCB), B. Metzger (UCB), M. Modjaz (UCB), A. Miller
(UCB), W. Lee (I. de Astronomia), S. Lopez (U. Chile), J. Norris
(NASA/Ames), P. E. Nugent (LBNL), M. Pettini (U. Cambridge), D.
Poznanski (UCB), A. L. Piro (UCB), E. Quataert (UCB), E. Ramirez-Ruiz
(UCSC), J. Shiode (UCB), and T. Sakamoto (GSFC/UMBC) report:
Further to GCN 7703 (Bloom et al.), we obtained additional imaging using
the Hubble Space Telescope (+WFPC2) of GRB 080503 (Mao et al., GCN 7665)
starting at 15:05:05 on UT 2008-05-12, about 9.2 days after the trigger.
Four exposures of 1000s each were acquired in F606W and in F814W.
The afterglow has faded significantly since the previous HST epoch, and
is not detected in either filter, or in a combined stack of the imaging
from both filters. The approximate limiting magnitude is F606W(AB) >
28.0, confirming the rapid fading observed previously. No sign of
host-galaxy emission is present in either filter.