Vulpecula com Ansere
is the name given by the Polish astronomer Hevelius for this Little Fox with the Goose, a constellation he invented in the seventeenth century. The sky map seen here was published in 1690 in Uranographia, just after the death of Johann Hevelius in 1687. Six other constellations made their appearance with this book, too. They are Canes Venatici, the hunting dogs, Lacerta, the lizard, Leo Minor, the lion cub, Lynx, the lynx, Sextans Uraniae, the sextant of Urania, and Scutum Sobieskii, the shield of the Polish hero-king, John Sobieski. You can see that several of these names have been shortened in modern use.

Vulpecula is a star group without any stories, because it was made up to fill an otherwise vacant part of the sky. Hevelius is reported to have said, “I wished to place a fox and a goose in the space of the sky well fitted to it; because such an animal is very cunning, voracious and fierce. Aquila and Vultur are of the same nature, rapacious and greedy.”

When the Summer Triangle is high in the sky, you can discover the fox by looking about halfway between Vega and Altair. But use binoculars, because even the brightest star in Vulpecula—a red giant that’s more than 200 light-years from Earth—is visible to the unaided eye only if you’re watching the sky from a dark location. The constellation is broad, 25° from east to west, but narrow, 10° from north to south. It lies to the north of Sagitta and Delphinus, south of Cygnus. Its brightest star is only of magnitude 4.4, but since the plane of the Milky Way passes through, there are a number of star fields that make it worth having a look.

The most interesting object is M27, the Dumbbell Nebula, which can be caught in 7 × 50 binoculars as a fuzzy star. With a small telescope it is a real gem.


The first hint of what will become of our Sun was discovered inadvertently in 1764. The 27th object on Messier's list, now known as M27 or the Dumbbell Nebula, is a planetary nebula, the type of nebula our Sun will produce when nuclear fusion stops in its core. M27 is one of the brightest planetary nebulae on the sky, and can be seen in the constellation Vulpecula with binoculars. It takes light about 1000 years to reach us from M27. Understanding the physics and significance of M27 was well beyond 18th century science. Even today, many things remain mysterious about bipolar planetary nebula like M27, including the physical mechanism that expels a low-mass star's gaseous outer-envelope, leaving an X-ray hot white dwarf.

This vast cloud is a shell of gas that was expelled from a dying star. It formed when a star similar to our own Sun entered the late stages of its life. The star first ballooned into a red giant—a cool star that’s hundreds of times its previous size. The star then kicked its outer layers into space. What remains of the star is extremely hot, so it produces lots of energy—enough to make the expanding shell of gas glow like a neon sign. The same fate awaits our own Sun—about five billion years from now.

About ten years ago, a Japanese astronomy satellite recorded a bright burst of X-rays from Vulpecula. From this research two teams of astronomers reported a “new” star, now called QZ Vulpeculae. Actually two stars bound together by mutual gravitational pull, they’re about 14,000 light-years from Earth, and no one had seen the system until 1988. One of the stars is massive but dark. The other contains less mass, but it is barely visible to large ground-based telescopes. Later, it was found that the two stars orbit each other once every eight hours, which means that they’re very close together.

And recently, two teams of astronomers independently measured the speed of the visible star. The information suggests that the dark companion is at least five times the mass of our Sun and probably more, which means it’s almost certainly one of the best black-hole candidates yet discovered.

The X-ray outburst ten years ago probably took place when the black hole pulled matter from its companion. The matter formed a disk around the black hole, which became hotter and hotter until it exploded—heralding the presence of a black hole.

Fox, you have stolen the goose, give it back again!
Otherwise the hunters will get you with the shooting gun!
German nursery rhyme


Return to Constellation Chronicles index
Return to EAS Home Page