How to Spot a Shiny Star That Is Flashing Red and Green (and Is Not an Airplane)
If you are fortunate enough to live where the stars are visible, those of us who live in cities hope you take advantage of it. Of course, we can see the moon when it’s not shining – maybe a random planet if it’s bright enough – but nothing more. Then there are moments when it seems that we are seeing a star – we realize that it is moving, hoping that it is even a shooting star – only to realize that it is an airplane.
But not every blinking object in the sky is an airplane. In fact, there is one star that blinks red and green at this time of the year. Here’s how to define it.
How to find the star of the Capella
Every autumn, residents of the Northern Hemisphere have the opportunity to see Capella’s star low in the northeastern sky at nightfall or in the early evening. According to EarthSky , this is a golden star – in fact, the two golden stars are larger and brighter than the Sun, and about the same temperature.
The most notable feature of the Chapel is that it flashes red and green, like one light from a heavenly festival. It rises in the sky all night, ending directly overhead in the early morning, but your best chance of seeing red and green flashing lights is in the early evening.
Why is it flashing green and red?
It turns out, according to EarthSky , all stars visible from Earth go through the same process:
The light from each star must pass through the Earth’s atmosphere before reaching our eyes. But not every star shines as prominently as Capella. The outbreaks occur because the Capella is low in the sky in the evening at this time of year. And when you look at an object low in the sky, you see more atmosphere than when the same object is overhead. The atmosphere divides or “refracts” light from a star, just as a prism divides sunlight.
While we don’t see this happening with other stars, Capella’s sheer size just makes it easy for us to find.