See a dolphin, fox, foal and more in the night sky

In the evening sky, four small, faint constellations spread out near and within the Summer Triangle can be seen.

First, about halfway between the stars Altair and Albireo, are the four stars marking Sagitta, the arrow. To the east are four stars forming a diamond with a fifth to the south. This is Delphinus, the dolphin, sometimes called "Job's Coffin." About as far to the east of Delphinus as the arrow is west, is a very faint trapezoid marking Equuleus, the little horse, or foal. Yet a fourth constellation lying between the first three and Cygnus is Vulpecula, the little fox.

Here we'll give detailed descriptions for each of the star patterns you can find in this patch of the night sky.

This sky chart shows the locations of the star patterns known as the Summer Triangle, Vulpecula (the little fox), Delphinus (the dolphin) and Sagitta (the arrow)
(Image credit: Starry Night software)

The "charming" dolphin

One of the smallest constellations is reaching its highest point in the sky about 90 minutes after sunset, Delphinus, the dolphin. Dolphins are known today as being the smallest whales. Their family name, in fact, is Delphinidae. That's probably how our "dolphin in the sky" got its name.

Our celestial dolphin is a star pattern that is composed only of faint stars, yet the stars are so close to each other that they can easily be seen on clear, dark nights. It certainly attracted the attention of ancient skywatchers. Here you will find a small diamond with perhaps one or two stars below it, which gives this group a prominence greater than you might otherwise expect from so faint a constellation. In his classic star guide, "The Stars: A New Way to See Them," author H. A. Rey noted, "There is something especially charming about it, positioned out in the dark just east of the bright summer Milky Way." Some reference books refer to the diamond as "Job's Coffin," though the origin of this name is unknown.

Delphinus, the dolphin, is a sea creature constellation with some strangely named stars making up its central star pattern.
(Image credit: Starry Nightsoftware)

According to legend, Arion, a Greek musician, was sailing on board a ship to Corinth, carrying a substantial cache of money and jewels. Unfortunately, the ship's crew planned to throw Arion overboard and abscond with his treasure. When confronted by the pirates, Arion requested that he be allowed to play his harp one final time. The music attracted Delphinus. Upon seeing the dolphin, Arion jumped overboard and was carried safely to shore. When the ship docked at Corinth, the crewmen were arrested and hanged. Arion recovered his treasure and the dolphin was given a place of honor in the sky.

There are some companies that will name a starafter you or a loved one — for a nominal fee. But such names are not officially recognized by any reputable astronomical institutions, such as the International Astronomical Union(IAU), which has the official authority to name celestial objects. However, one person apparently got around this using two stars in Delphinus. In star atlases and catalogs, we find these two odd names: Sualocin and Rotanev. They first appeared in the Palermo Star Catalog in 1814. But where did they come from? The English astronomer Thomas Webb finally solved the mystery by reversing their letters, revealing the name of Nicolaus Venator, a Latinized form of Niccolo Cacciatore, the assistant and eventual successor of Palermo Observatory's director, Giuseppe Piazzi. But was it Piazzi or Cacciatore who was responsible for these inverted monikers? Nobody knows.

Hercules' arrow?

(Image credit: NASA/Stellarium)

Between Aquila, the eagle and Cygnus, the swan is a longish figure of four stars, which can pass for an arrow. Sagitta, the arrow is one of the original 48 ancient constellations, with the four stars assigned to it by the Greek astronomer Eratosthenes. The mythology of the arrow is confusing, but once its shape becomes familiar — and it really is true to its name — you should have no trouble sighting it. Although it's a small star pattern, it's quite striking for its size and is located halfway between the heads of the eagle and swan, within the Milky Way.

One legend suggests that the arrow was supposedly shot by Hercules at the Stymphalian Birds as one of his 12 labors. In the sky, the only birds within close range of Hercules were Aquila, the eagle and Cygnus, the swan. If he was trying to bring one or both down, it appears that he missed them both! Note also the similarity in the names of the constellations Sagitta ("arrow") and Sagittarius("archer").