Proper Motions in the Ejecta of η Carinae with a 50 Year Baseline

Observations of η Carinae from three separate epochs spanning a total of 50 years are used to measure the proper motions of several easily identifiable features in the Homunculus Nebula. Our principal conclusion is that the equatorial features were ejected significantly after the "Great Eruption," very likely in the outburst that occurred around 1890. The rest of the inner nebula was ejected during the bright phase of 1822 to 1856 that climaxed with the eruption of 1843. The expansion of the bipolar lobes appears to be primarily linear, with a scatter in ejection dates during the period of the Great Eruption. We find a mean ejection date for the southeast polar lobe of 1843.8 ± 7.3 yr, and an ejection date of 1885.8 ± 6.5 yr for the equatorial ejecta.