Back to: Weekend Sky Report
March 13, 2020
All right—I’m no trickster, so I’d make a lousy leprechaun. No… there are no green stars. But there are a few that can appear green.
Blue stars that are really close to red stars can appear to us as a greenish blue. One good example is Antares B, the binary companion to the red giant Antares A, the heart of Scorpius.
If you wake up EARLY on St. Patrick’s Day, or any day in the next month or so, you can’t miss bright orange Antares A low in the southern sky. To see Antares B, you’ll need a decent-sized telescope. Point it right at Antares, and look for a much dimmer, greenish blue companion. That’s Antares B. Now again, the only reason it appears green is because a giant bright red star is right next door. It’s an optical trick. But as long as you’re outside with a big telescope, there are a couple other nearby objects you’ll want to see.
First, let’s address the VERY bright objects to the southeast. Those are all planets. The brightest are Mars and Jupiter, but that dimmer yellow one is that jewel of the solar system—Saturn. Of course, if you have a telescope good enough to see Antares B, you probably already know how good the planets look through it.
Not to mention there’s a waning moon out in the morning with the terminator, or shadow accentuating all those great surface features like craters and mountains.
So if you’re up for some early morning observation, there’s plenty to see in the southern sky.