Mars will slide only 3/4 of a degree south of the striking double star Gamma Virginis tomorrow morning. Also known as Porrima, the close proximity of star and planet will certainly get your attention if you’re willing to risk the winter chill. They’re ideally placed too – high in the southern sky before the start of dawn.
If you have any trouble finding this temporary “double”, just follow the celestial steppingstones of crescent moon, Saturn and Spica to lead you there.
Right now, Porrima’s two equally bright stars (both are magnitude 3.6) are separated by 2 arc seconds. To split them apart you’ll need a 3-inch (80mm) or larger scope magnifying around 150x. They’re a beautiful sight – two tiny, close set pearls glimmering in black velvet.
While you’re at it, don’t miss looking at nearby Mars as well as Saturn and the lunar crescent. Heck, they’re all laid out for us like a four-course meal.
Porrima’s stellar twins are similar to the sun but hotter and nearly identical in size. They go around each other every 169 years in an elliptical orbit that cyclically brings them closer together and farther apart as seen from Earth. Closest approach happened in 2005 when the duo was separated by the same distance Jupiter is from the sun or about 500 million miles. When farthest apart, around the year 2080, they’ll be twice Pluto’s distance from each other.
Right now the duo is “opening up” and easier to see in small scopes, but you’ll need to use higher magnifications. Let us know how you fare.