Enjoying EarthSky? Subscribe.

181,142 subscribers and counting ...

Looking out our Milky Way galaxy’s south window


Tonight for November 15, 2015

Tonight, or any clear November evening, try using the Great Square of Pegasus to star-hop to our galaxy’s south window. In other words, you’ll be looking away from the flat plane of the Milky Way – where most of our galaxy’s stars reside – and southward toward intergalactic space.

Here’s how to do it. Every year in November, as seen from mid-northern latitudes, the Great Square of Pegasus appears high in the south to overhead by about 8 p.m. This large asterism really does look like a large square pattern, with four medium-bright stars marking the corners. Draw a line through the Great Square’s two westernmost (or right-hand stars), and extend that line southward to land on the bright star Fomalhaut in the constellation Piscis Austrinus the Southern Fish.

Why find Fomalhaut? When you look at this star – sometimes called the Autumn Star or the Loneliest Star – you are looking some 90 degrees from the plane of our galaxy’s equator.

Our Milky Way galaxy is round and flat, like a pancake. When you look toward Fomalhaut, you’re looking away from the pancake, and out the south window of the galaxy. In other words, we’re looking away from the star-packed disk of the galaxy, into extragalactic space and the realm of galaxies.

Sky chart of the constellation Sculptor

The south galactic pole lies in the direction of the constellation Sculptor.

Want the exact location of the south galactic pole? It lies east of Fomalhaut, in the faint constellation Sculptor.

Bottom line: Tonight, try using the Great Square of Pegasus to find the star Fomalhaut. Once you’ve found Fomalhaut, you’re on your way to visualizing looking out the south window of our Milky Way galaxy.

Easily locate stars and constellations during any day and time with EarthSky’s Planisphere.