Proper Motions in Eta Carinae Using a Half-Century Temporal Baseline

Session 46 - Variable Stars - Late Type.
Display session, Thursday, January 08
Exhibit Hall,

[46.05] Proper Motions in Eta Carinae Using a Half-Century Temporal Baseline

N. Smith (U. Minnesota and Boston U.), R. D. Gehrz (U. Minnesota)

Observations of eta Carinae from three separate epochs spanning a total of fifty years are used to measure the proper motions of several easily identifiable features in the homunculus. We conclude that the equatorial ejecta originated during the 1890 outburst, whereas the rest of the inner nebula was ejected during the bright phase of 1822 to 1856, peaking in the eruption of 1843. The expansion of the nebula is primarily linear, although irregularities exist, corresponding to a scatter of ejection dates within ten years of 1843. We detect a slight outwardly radial acceleration of condensations in the northwest lobe. This acceleration is consistent with earlier studies in the literature.

Program listing for Thursday