Epsilon Aurigae ( Aur / Aurigae) is a star in the constellation Auriga. It also has the traditional names Haldus, Almaaz, or Al Anz. Epsilon Aurigae is an eclipsing binary, whose brightness varies in apparent visual magnitude between +3.0 and +3.8 with a period of about 9,890 days (~27.1 years). It is approximately 2,000 light years distant.
Title: Gearing Up for Epsilon Aurigae's First Eclipse of the Millennium Authors: J. L. Hopkins, L. Schanne, R. E. Stencel
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 HERE.
Read more (231kb, PDF) CALENDAR OF ECLIPSE EVENTS: 2009 Aug 6th - predicted start of eclipse, rising with sun as a morning star 2009 Nov/Dec - eps Aur transits at midnight --> evening star 2009 Dec 21 - predicted start of totality, evening star 2010 May - eps Aur setting with the sun, mid eclipse brightening? 2010 Aug 1st - predicted time of mid-eclipse, early morning star 2010 autumn - end of mid-eclipse brightening? 2010 Nov/Dec - eps Aur transits at midnight --> evening star 2011 March 12 - predicted end of totality, evening star 2011 May 15 - predicted end of eclipse, next one starts in 2036.
Title: Recent UBVJH Photometry of Epsilon Aurigae Authors: Jeffrey L. Hopkins, Robert E. Stencel
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 (Autumn 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 (Autumn 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.