  We have confirmed the existence of the transiting super Neptune extrasolar
planet HAT-P-11b. On May 1, 2009 UT the transit of HAT-P-11b was detected at
the University of Arizona's 1.55m Kuiper Telescope with 1.7 millimag rms
accuracy. We find a central transit time of T_c = 2454952.92534+/-0.00060 BJD;
this transit occurred 80+/-73 seconds sooner than previous measurements (71
orbits in the past) would have predicted. Hence, our transit timing rules out
the presence of any large (>200 s) deviations from the ephemeris of Bakos et
al. (2009). We obtain a slightly more accurate period of
P=4.8878045+/-0.0000043 days. We measure a slightly larger planetary radius of
R_p=0.452+/-0.020 R_J (5.07+/-0.22 R_earth) compared to Bakos and co-workers'
value of 0.422+/-0.014 R_J (4.73+/-0.16 R_earth). Our values confirm that
HAT-P-11b is very similar to GJ 436b (the only other known transiting super
Neptune) in radius and other bulk properties.
