Which star is loneliest? Most people would say the answer is Fomalhaut, a bright star in the constellation Piscis Austrinus the Southern Fish.
But before looking for this star, you might want to seek out the planets Venus and Saturn in the west at evening dusk. Although the planet Mercury and the star Spica are in conjunction below Venus and Saturn, they are too low in the glare of evening twilight to observe from mid-northern and far-northern latitudes. However, the northern tropics and the Southern Hemisphere should be able to catch Mercury and Spica in their sky at dusk and/or early evening.
But back to Fomalhaut. From mid-northern latitudes, Fomalhaut doesn’t climb over the southeast horizon until after nightfall. The coming month or so presents a good time to see this star. So go outside around mid-vevening – and learn to keep company with the loneliest star.
On this autumn night, at about 8 to 9 p.m., look for a solitary star that’s peeking out at you just above the southeast horizon. See it? No other bright star sits so low in the southeast at this time of year.
Fomalhaut is a bright white star. It dances close the southern horizon until well after midnight on these early autumn nights. Fomalhaut reaches its highest point for the night in the southern sky at roughly 11 p.m. local time (12 midnight daylight-saving time). Fomalhaut sets in the southwest at roughly 2:30 a.m. local time (3:30 a.m. local daylight-saving time).
Fomalhaut is sometimes called the loneliest star because it is the brightest star in an otherwise empty-looking part of the sky. It is also sometimes called the Lonely One, or the Solitary One, or sometimes the Autumn Star. Depending on whose list you believe, Fomalhaut is either the 17th or the 18th brightest star in the sky. Roughly translated from Arabic, the star’s name means mouth of the fish or whale. Its constellation, Piscis Austrinus, represents the Southern Fish.
Besides being one of the brighter stars in the night sky, Fomalhaut has interest to professional astronomers. In recent years, this star has been found to have a protoplanetary disk. This is a ring of dust that surrounds Fomalhaut and a companion star within one light-year. This dust ring surrounding these stars might someday form into planets. Perhaps planets are forming there now. Just think of that as you gaze upon Fomalhaut, the lonely autumn star!