Abstract
The advent of direct gravitational wave detection has allowed for several tests of general relativity. Here, the Hawking black hole area theorem is tested using data from the binary black hole merger GW150914. Parameters are obtained using an estimation technique that allows for sky location and coalescence time variation. These parameters have traditionally been set to fixed values due to numerical complications. Using this method leads to more complete accounting of statistical uncertainties in parameter estimation, which subsequently leads to more robust area estimates. This technique also allows for a robust test of the presence of the ℓ = m = 2, n = 1 overtone in GW150914, the existence of which has been debated in the literature.