During the evening now, the stars of the autumn season cover much of the eastern and southern parts of the sky. There are very few brilliant stars in these areas. But now that the Moon is waning and rises after 10 p.m. and the late evenings are relatively dark, it's a good time to look for some interesting constellations in this part of the sky.
There is Capricornus, the Sea-Goat; Aquarius, the Water Bearer; Piscis Austrinus, the Southern Fish; Pisces, the Fishes; Cetus, the Whale (sometimes called the Sea Monster); and Eridanus, the River.
In fact, this whole area has been called the "Wet Region" or the "Celestial Sea," probably because it is rather vague and dim like some dark pool.
All these constellations have a rich body of lore and mythology associated with them. They have been associated with the rainy season of Mideast lands. This attribution actually refers not to the constellations visibility in the night sky, but to the Suns location in front of their stars (Capricornus, Aquarius and Pisces belong to the zodiac).
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| NightSky Friday | |
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 | SKY MAP: The Celestial Sea constellations are visible at 9 p.m. local time with two exceptions: Eridanus is below the horizon, as is half of Cetus. The constellations move up in the sky, east to west, during the night, so all of Cetus and part of Eridanus becomes visible low on the horizon by midnight. This view shows the sky at midnight in late September, as seen from mid-northern latitudes.
| | * Graphic made with Starry Night Software | | | |
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| ART: The same approximate view as the sky map, but with the illustrations of the constellations rendered by Starry Night software.
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| FIND A STAR: This view shows the sky at 10:00 p.m. local time in late September, as seen from mid-northern latitudes.
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There is also a mythological connection between these dim star pictures and an ancient flood in the Tigris-Euphrates basin, which has sometimes been linked to the Deluge in Genesis.
Due south just before local midnight is the star pattern that contains the brightest star of this watery fraternity: Piscis Austrinus, the Southern Fish. Across southern Canada, the northern United States and much of Europe, the stars that make up this constellation usually cannot be seen. Although above the horizon, they are too low and dim to penetrate the horizon haze.
At more southerly latitudes these stars are much higher up in the sky, though still quite dim.
The constellations main star is all the more conspicuous: silvery-white Fomalhaut, ranked as the 18th brightest star in the sky and the only first magnitude star in the whole collection of watery constellations.
An imaginary line drawn through the two bright stars on the right-hand side of the Great Square of Pegasus and continued far downward points straight to Fomalhaut.
Indeed, Fomalhaut is the only true first magnitude star of autumn. Though Vega, Altair and Deneb are still very much present high in the west, they form the Summer Triangle. Fomalhaut lies in an empty region of the autumn skies, and is sometimes referred to as "The Solitary One."
In her book "The Friendly Stars" in the early 1900s, Martha Evans Martin wrote, "The loneliness of the star, added to the sombre signs of approaching autumn, sometimes gives one a touch of melancholy. In November and December, when the winter stillness has fallen upon us, a glance toward the southwest will discover Fomalhaut, still placid and alone."
Fomalhaut is often described in various observing books as "reddish," though it is probable that the effects of our atmosphere are responsible for this impression, as this star is always seen at a low altitude for northern observers.
Fomalhaut is Arabic for "mouth of the fish." It lies at a distance of 25 light-years and is approximately twice the diameter of the Sun and 14 times more luminous.
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