Gearing Up for Epsilon Aurigae's First Eclipse of the Millennium

TL;DR

This paper reviews observational data on epsilon Aurigae leading up to its 2009 eclipse, highlighting changes in light variation and eclipse durations to inform future studies of this long-period binary system.

Contribution

It provides a comprehensive summary of observational results and trends observed in epsilon Aurigae prior to its 2009 eclipse, aiding future research.

Findings

Decrease in low amplitude light variation quasi-period over 20 years

Shortening of eclipse egress duration

Lengthening of total eclipse duration

Abstract

The mysterious 3rd magnitude long period eclipsing binary star system epsilon Aurigae is predicted to be starting its 2 year eclipse in the late summer of 2009. While this is when the real excitement starts, much is to be learned before first contact. This paper discusses current observational results that have accumulated thus far, using photometric monitoring, H-alpha spectroscopy and with other data sources. Key among the findings are that (1) the low amplitude light variation quasi-period has decreased significantly over the past 20 years, and (2) that the duration of egress, eclipse-to-eclipse has been decreasing, while the duration of total eclipse has been increasing. The website for the observing campaign is: www.du.edu/~rstencel/epsaur.htm .