A Revised Historical Light Curve of Eta Carinae and the Timing of Close Periastron Encounters

Understand

The historical light curve of the 19th century "Great Eruption" of etaCar provides a striking record of violent instabilies encountered by the most massive stars.

• We report and analyze newly uncovered historical estimates of the visual brightness of etaCar during its eruption, and we correct some mistakes in the original record.
• The revised light curve looks substantially different from previous accounts: it shows two brief eruptions in 1838 and 1843 that resemble modern supernova impostors, while the final brightening in December 1844 marks the time when etaCar reached its peak brightness.
• We consider the timing of brightening events as they pertain to the putative binary system in etaCar: (1) The brief 1838 and 1843 events peaked within weeks of periastron if the pre-1845 orbital period is shorter than at present due to the mass loss of the eruption.