Tonight, 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. At this time 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. The south galactic pole lies east of Fomalhaut, in the faint constellation Sculptor.
Sky chart of the constellation Sculptor
The constellation Sculptor lies to the east of the star Fomalhaut, marking the direction of the South Galactic Pole. (See above sky chart.) Try using the Great Square of Pegasus to find the star Fomalhaut, and you have what it takes to look out the south window of the Milky Way galaxy on a dark, moonless night!
By the way, are you an early riser? If so, make sure to use the moon to find the nearby planet Jupiter and the star Regulus in the November 15 predawn and dawn sky.