As autumn nights grow longer, one of the sky’s brightest stars makes a dazzling appearance. Fomalhaut, sometimes called the “Fall Star” or “Autumn Star,” is just 25 light-years away. It’s among the 20 brightest stars visible from Earth.
Fomalhaut is more than just a bright star making a brief seasonal appearance. The ancient Persians called it a Royal Star, along with Regulus in Leo, Aldebaran in Taurus and Antares in Scorpius. These four stars were thought to guard the sky, each positioned at the seasonal turning points of solstice and equinox. With the September equinox coming on Sept. 22, Fomalhaut is about to reveal its special significance.
Where And When To Look
Fomalhaut sits low in the southern sky from September through December, reaching its best visibility shortly after the equinox in October. From mid-northern latitudes, Fomalhaut never climbs high, often hovering close to the horizon. That means local conditions matter: you’ll need an unobstructed view of the southern horizon.
Fomalhaut is in the constellation Piscis Austrinus, “the Southern Fish,” just beneath the constellation Aquarius, but since its stars are faint, that doesn’t help the casual stargazer.
Luckily, a planet comes to the rescue this year. Saturn, unmistakable in the southern sky, shines to the upper-left of Fomalhaut. So all you have to do is find Saturn, and scan the southern horizon to its lower-right until you find a bright star.
Observing Tips And Related Sights
Unlike the easy-to-spot stars of summer, catching Fomalhaut requires patience, clear horizons, and a keen eye — especially for stargazers in the Northern Hemisphere. However, with Saturn nearby, it’s not difficult.
Fomalhaut is thought to be part of the Castor Moving Group, a loose collection of stars that may have formed together in an ancient open cluster. Although its member stars are scattered across the sky today, their shared motion through space reveals them to be from the same family. Two other notable members are the bright stars Vega in Lyra and Castor in Gemini. Look high above Fomalhaut and you’ll find Vega, the highest star in the obvious Summer Triangle asterism. For Castor, you’ll have to wait for the pre-dawn hours, when it rises with Jupiter. However, by December, Castor will be visible earlier in the evening sky.
For exact timings, use Stellarium Web for a sky chart and Night Sky Tonight: Visible Planets at Your Location for positions and rise/set times for planets.
Wishing you clear skies and wide eyes.
