Here are the links I promised you all about the Epsilon Aurigae debris cloud imaged by the CHARA Array. This is the star I was discussing with the Docent at Mt. Wilson when he was explaining the CHARA Array. This is the star in that triangle I pointed out to some of you when we were looking at Capella through the 60″. I have nicknamed this one the “Weirdo Star:” because it has been a major mystery for more than 150 years.

1. Here is a video presentation explaining the system. This was put out by Timothy Ferris prior to the last two year long eclipse of the system.

2. Here is a video constructed using CHARA Array data of the beginning of the eclipse. Bear in mind that this video represents more than 6 months worth of data.

3. For those interested -here is a more detailed explanation. This star was extensively studied during the past eclipse using a worldwide collaboration between the Amateur, Professional, and Physics Communities

4. Here is the light curve of the eclipse. This chart contains visual estimates (black dots) and both V (green dots) and B (blue dots) measurements. When you hear the term “Color Index” or “B-V” index this is what they are referring to. The green measurements are standard “V” which approximates what the eye would see (green-yellow). The “B” or Blue filter measures the -wait for it- “Blueness”. The reference points are defined by certain well defined reference stars. For example the star Vega is defined to define the zero point where B-V=0. If the B-V is a positive number the star is redder and cooler than Vega. If the B-V is a negative number the star is bluer and hotter than Vega. As you can see from this light curve the B mag is dimmer than the V mag so B-V will be positive. For Epsilon Aurigae the value of B-V=.54 For the Sun the B-V = .66. So Epsilon Aurigae is a bit hotter and bluer than the Sun – yellowish white.

Of the dots in this graph 12 of the black ones are my measurements.

Dave Majors
CCAS (Central Coast Astronomical Society)
AAVSO (American Association Of Variable Star Observers)