Predicted timing of Eta's spectroscopic event in 2003

Prediction graph

This figure, constructed in August 2001, shows when the 2003 spectroscopic event should occur if it repeats the behavior of 1997-98. These plots represent ground-based and RXTE data obtained then, shifted forward by 2023 days = 5.54 years. In fact we didn't expect an exact recurrence, but these are the best predictions that were available before June 2003.

The ground-based observations represent an unresolved mixture of the stellar wind plus ejecta farther out; until HST/STIS data are obtained we can't tell exactly where the changes occurred nor what they were. Two faint vertical lines indicate phases in the cycle when the earliest HST/STIS observations were made. The first of them included only a minimal sample of wavelengths, six weeks after the event began.

©2003,2004 The University of Minnesota