Recent UBVJH Photometry of Epsilon Aurigae

TL;DR

This paper reports on ongoing UBVJH photometric observations of epsilon Aurigae over multiple seasons, highlighting recent variability patterns, improved measurement precision, and preparations for the upcoming eclipse in 2009.

Contribution

It provides new long-term photometric data including near-infrared observations and compares seasonal variations, aiding future eclipse predictions and observational campaigns.

Findings

Detected a 66.2-day variation in 2003-2005 seasons.

Observed a return to a quiet maximum in 2006.

Achieved high-precision photometry with standard deviations below 0.01 magnitudes.

Abstract

Since first observed in the early 1980s, the Hopkins Phoenix Observatory continues its UBV band observations of the long period (27.1 years) eclipsing binary star system epsilon Aurigae. The UBV observations routinely produce standard deviations or data spread better than 0.01 magnitudes many times approaching 0.001 magnitudes. A new infrared photometer has allowed the addition of near-infrared observations for the JH bands. Typical near-infrared observations approach a standard deviation of data spread of 0.01 magnitudes. The 2003 - 2005 seasons (Fall through Spring) of epsilon Aurigae observations showed a 66.2 day variation that gradually increases in average and peak magnitude in the UBV bands. The 2006 season (Fall 2006 to Spring 2007) data show what appears to be a fall-back to a quiet period near maximum amplitude of V= 3.00. This paper presents the data and compares the current season to the past several seasons. The next eclipse is predicted to begin in 2009 and an international campaign has been organized to coordinate new observations. These website links are: [http://www. hposoft.com/Campaign09.html ] and [ http://www.du.edu/~rstencel/epsaur.htm ] .