Northern California here, I've seen it every night for the last few months in the northeastern sky...
Quoting: simplestoner What you seeing is a star called Capella.
"Does golden Capella sparkle red and green?"
[
link to earthsky.org]
Why does a golden star flash red and green when it’s low in the sky?
The reality is that every star’s light must shine through Earth’s atmosphere before reaching our eyes. The atmosphere causes stars to twinkle. The key to stars’ flashing colors is that, when you look at an object low in the sky, you’re looking through more atmosphere than when that object is overhead.
The atmosphere splits or “refracts” the star’s light, just as a prism splits sunlight. Capella’s red and green flashes don’t come from the star itself. They come from refraction of Capella’s light by our atmosphere, when this star is low in the sky.
Why are these flashes of color so noticeable with Capella, and not with others stars? Simply this. Capella is a bright star. It’s the 6th brightest star in Earth’s sky, not including our sun.
Look for Capella low in the northeast around mid-evening, noting that this brilliant beauty sparkles with the colors of the rainbow.