Unlike other constellations, Vulpecula was not named from a character or creature from mythology that some early astronomer thought the grouping of stars resemembled. When Johannes Hevelius named the constellation in 1687, he chose the name ‘Vulpecula et Anser’ or ‘fox with goose,’ as he believed that the shape looked like a fox bringing a goose to Cerberus, the “hound of Hades” that guarded the gates of the underworld.
The constellation Cerberus has since become obsolete, while Hevelius’ other cluster of stars, the fox and the goose, has since been renamed Vulpecula (the fox). As a homage to its original title, the brightest of the stars in the constellation is called Anser as a nod to the now forgotten goose.
Vulpecula is a northern constellation that can be seen by observers situated between +90° and -55° of lattitude. It is the night sky’s 55th largest constellation, and is located at the centre of the Summer Triangle, and therefore close to the constellations of Aquila, Lyra and Cygnus. Vulpecula is best seen in September when the Summer Triangle is prominent in the sky, and you should start your search about partway between Vega and Altair. It is best to use a telescope or binoculars with a minimum magnification of 7×50 to spot this faint constellation.
Anser (Alpha Vulpeculae), the brightest star in Vulpecula, has a visual magnitude of 4.44, and is an M0III red giant located 297 light years away from our sun. Also known as Lucida Anseris or Lukida, the star is actually part of a binary system together with the orange spectral type K0III star 8 Vulpeculae, which is 484 light years from Earth and shines with a magnitude of 5.81.
– 23 Vulpeculae
23 Vulpeculae is located 328 light years distant, and shines wih a magnitude of 4.52, making it the second brightest star in the constellation. It is of spectral class K3III (orange giant), and forms part of a triple star system.
– 31 Vulpeculae
31 Vulpeculae shines with a magnitude of 4.59, making it the third brightest star in Vulpeculae. It is located about 216.57 light years away, and is actually a variable star that has been given the stellar classification G7III (yellow giant).
– PSR B1919+21
In 1967, PSR B1919+21 was discovered by Jocelyn Bell Burnell and Antony Hewish, marking the official first discovery of a pulsar. Hewish would go on to receive the Novel Prize for Physics for the feat, with the pulsar receiving its unusual name by combining the numbers of its declination and right ascension with the word pulsar. When it was first discovered, PSR B1919+21 was thought to perhaps be the first signs ever of an alien civilization; however, Thomas Gold and Fred Hoyle were able to determine that the signals being emitted by the star were actually just the strong magnetic fields of the rotating neutron stars.
Originally named CP 1919, PSR B1919+21 is 2283.12 light years away from the sun, and has a period of 1.3373 seconds, and a pulse width of 0.04 seconds.
Notable Deep Sky Objects
– The Dumbbell Nebula
Vulpecula just so happens to be home to one of the most well known planetary nebulae–the Dumbbell Nebula. It is believed to have been formed when a star emitted gas before it died, and its name comes from its double lobed shape that makes it look like a hand weight. Some people refer to it as the Apple Core Nebula or by its official name Messier 27, which comes from its discoverer, Charles Messier, who first spotted it in 1764.
Located approximately 1360 light years from our solar system, the Dumbbell Nebula has a magnitude of 7.5 and is 8 arc minutes in diameter. You can see it with most binoculars and hobby telescopes, and observers should be sure to check out its central white star, which is the largest known white dwarf yet discovered.
– NGC 7052
Look closely at Vulpecula, and you’ll see the elliptical galaxy NGC 7052, which is about 191 million light years away, shines with a visual magnitude of 13.4, and is known to give off radio waves. Scientists estimate that the galaxy is 3700 light years in diameter and is the result of a two galaxies colliding. At its centre is a black hole that is 100 times more massive than the galaxy itself, and it is predicted that within the next several billion years it will swallow the whole of NGC 7052.
– Brocchi’s Cluster
Brocchi’s Cluster is a star cluster that is known by a number of different names, including Collinder 399, and Al Sufi’s Cluster, after the Persian astronomer Al Sufi who in 964 AD wrote about it in his “Book of Fixed Stars.” Without knowing of Sufi’s discovery, Giovanni Batista Hodierna found the cluster in the 17th century, while the name Broochi is owed to the amateur astronomer who in the 1920s first mapped the star cluster. Collinder 399 references the Swedish scientist Per Collinder who listed the cluster as one of 471 open clusters in his catalog of 1931.
In any case, Brocchi’s Cluster refers to the group of stars that are located in Vulpecula, close to the border of the constellation Sagitta. Its 10 brightest stars are arranged in an asterism that is sometimes referred to as the Coathanger, and you can see this portion of Brocchi’s Cluster without the use of a telescope or binoculars.