How sky position uncertainty quietly skews black hole ringdown measurements

When a black hole merger ends, the remnant 'rings down' like a struck bell, and reading those tones tests whether Einstein's theory holds. Standard analyses pin the sky location of the source to a single best-guess value, which artificially tightens constraints on the ringdown amplitudes and can introduce bias. Treating sky position as uncertain—and marginalizing over it properly—gives more honest error bars, while amplitude *ratios* stay stable regardless, making them the safer observable for testing black hole physics.