eta Carinae Continues to Evolve (Abstract)

Volume 43 number 1 (2015)

John C. Martin

University of Illinois at Springfield Observatory, One University Plaza, MS HSB 314, Springfield, IL 62704; jmart5@uis.edu

Abstract

(Abstract only) eta Carinae affords us a unique opportunity to study the pre-supernova evolution of the most massive stars. For at least the last half century, it has maintained a 5.5-year spectroscopic cycle that culminates with abrupt decreases in the strong stellar wind emission features. Over the last 15 years, the star has brightened at an accelerated rate and altered its spectrum, in addition to the spectroscopic cycle, indicating an ongoing change in state. We present Hubble Space Telescope spectroscopy and synthetic photometry from the most recent spectroscopic event (2014.5) that shows notable differences with past events and provides clues to the on-going evolution of the star.