We present here three transit observations of HAT-P-9b taken on 14 February 2010 , 18 February 2010 , and 05 April 2010 UT from the University of Arizona ’ s 1.55 meter Kuiper telescope on Mt .
Bigelow .
Our transit light curves were obtained in the I filter for all our observations , and underwent the same reduction process .
All three of our transits deviated significantly ( \approx 24 minutes earlier ) from the ephemeris of Shporer et al .
( 2008 ) .
However , due to the large time span between our observed transits and those of Shporer et al .
( 2008 ) , a 6.5 second ( 2 \sigma ) shift downwards in orbital period from the value of Shporer et al .
( 2008 ) is sufficient to explain all available transit data .
We find a new period of 3.922814 \pm 0.000002 days for HAT-P-9b with no evidence for significant nonlinearities in the transit period .