Previous
abstract 
Next abstract
By comparing the photometry of a high-redshift Type Ia supernova to the nearby Type Ia magnitude distribution, we can measure the deceleration parameter $q_0$. We have studied the main sources of error in the distant-supernova photometry, in the nearby calibration, and in the comparison of the two. This leads to an estimate of the current $q_0$ measurement error and strategies to substantially improve the accuracy of this result. In particular, we will report the implications for $q_0$ of the analysis of Supernova 1992bi, which we discovered at $z=0.458$. Our current schedule of supernova searches and follow-up will allow us to address the main sources of error in $q_0$, since we will be using dozens of well-observed supernovae, both distant and nearby, in the calculation.
