Vulpecula is a faint
constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object.
The first constellati ...
in the northern sky. Its name is
Latin
Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
for "little
fox", although it is commonly known simply as the fox. It was identified in the seventeenth century, and is located in the middle of the
Summer Triangle (an
asterism consisting of the bright stars
Deneb,
Vega, and
Altair).
Features
Stars
There are no stars brighter than 4th magnitude in this constellation. The brightest star in Vulpecula is
Alpha Vulpeculae, a
magnitude 4.44
m red giant at an approximate distance of 291
light-year
A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by the International Astr ...
s. The star is an
optical binary (separation of 413.7") that can be split using binoculars. The star also carries the traditional name Anser, which refers to the goose the little fox holds in its jaws.
23 Vulpeculae is the second brightest star in the constellation.
In 1967, the first
pulsar
A pulsar (''pulsating star, on the model of quasar'') is a highly magnetized rotating neutron star that emits beams of electromagnetic radiation out of its Poles of astronomical bodies#Magnetic poles, magnetic poles. This radiation can be obse ...
,
PSR B1919+21, was discovered in Vulpecula by
Jocelyn Bell, supervised by
Antony Hewish, in
Cambridge
Cambridge ( ) is a List of cities in the United Kingdom, city and non-metropolitan district in the county of Cambridgeshire, England. It is the county town of Cambridgeshire and is located on the River Cam, north of London. As of the 2021 Unit ...
. While they were searching for scintillation of radio signals of
quasar
A quasar ( ) is an extremely Luminosity, luminous active galactic nucleus (AGN). It is sometimes known as a quasi-stellar object, abbreviated QSO. The emission from an AGN is powered by accretion onto a supermassive black hole with a mass rangi ...
s, they observed pulses which repeated with a
period of 1.3373
second
The second (symbol: s) is a unit of time derived from the division of the day first into 24 hours, then to 60 minutes, and finally to 60 seconds each (24 × 60 × 60 = 86400). The current and formal definition in the International System of U ...
s.
Terrestrial origin of the signal was ruled out because the time it took the object to reappear was a
sidereal day instead of a
solar day. This anomaly was finally identified as the signal of a rapidly rotating
neutron star
A neutron star is the gravitationally collapsed Stellar core, core of a massive supergiant star. It results from the supernova explosion of a stellar evolution#Massive star, massive star—combined with gravitational collapse—that compresses ...
. Fifteen years after the first pulsar was discovered, the first
millisecond pulsar,
PSR B1937+21, was also discovered in Vulpecula, only a few degrees in the sky away from PSR B1919+21.
Vulpecula is also home to
HD 189733 b, one of the closest extrasolar planets studied by the now-retired
Spitzer Space Telescope. On 11 July 2007, a team led by
Giovanna Tinetti published the results of their observations using the Spitzer Space Telescope concluding there is solid evidence for significant amounts of water vapor in the planet's atmosphere. Although HD 189733b with atmospheric temperatures rising above 1,000 °C is far from being habitable, this finding increases the likelihood that water, an essential component of life, would be found on a more Earth-like planet in the future.
Also located in Vulpecula is
soft gamma repeater SGR 1935+2154. In 2020 it emitted a
fast radio burst, the first one to be observed in the Milky Way.
Deep-sky objects

The
Dumbbell Nebula (M27), is a large, bright
planetary nebula which was discovered by the French astronomer
Charles Messier in 1764 as the very first object of its kind. It can be seen with good
binoculars in a dark sky location, appearing as a dimly glowing disk approximately 8
arcminutes in diameter.
[
] The nebula is approximately 9,800 years old.
A
telescope
A telescope is a device used to observe distant objects by their emission, Absorption (electromagnetic radiation), absorption, or Reflection (physics), reflection of electromagnetic radiation. Originally, it was an optical instrument using len ...
reveals its double-lobed shape, similar to that of an hourglass.
Brocchi's Cluster (Collinder 399) is an
asterism formerly thought to be an
open cluster
An open cluster is a type of star cluster made of tens to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way galaxy, and ...
. It is also called "the Coathanger" because of its distinctive star pattern when viewed with binoculars or a low power telescope.
NGC 7052 is an
elliptical galaxy in Vulpecula at a distance of 214 million light-years from Earth. It has a central
dusty disk with a diameter of 3700 light-years; there is a
supermassive black hole
A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions, of times the mass of the Sun (). Black holes are a class of astronomical ...
with a mass of 300 million solar masses in its
nucleus. Astronomers surmise that the disk is the remnant of a smaller galaxy that
merged with NGC 7052.
Jets can be seen emanating from the galaxy, and it has very strong
radio emissions. This means that it is also classified as a
radio galaxy.
The eastern part of Vulpecula is occupied by the
Hercules–Corona Borealis Great Wall. It is a galaxy filament, with the length of 3,000 megaparsecs, making it the largest known structure in the universe.
Stellar association
Vulpecula contains an OB-association of young stars, called the
Vulpecula OB-association or Vul OB1. The association contains nearly 100
OB-stars and over 800
young stellar objects. It lies in the galactic plane, at a distance of about 2300
parsec
The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to or (AU), i.e. . The parsec unit is obtained by the use of parallax and trigonometry, and ...
. It contains the emission-line nebulae Sh-86, Sh-87 and
Sh-88. Vul OB1 has a length of about 100 parsec and is sculpting many pillar-like structures in this region.
History
In the late 17th century, the astronomer
Johannes Hevelius created Vulpecula. It was originally known as Vulpecula cum ansere ("the little fox with the
goose") or Vulpecula et Anser ("the little fox and the goose"), and was illustrated with a goose in the jaws of a fox. Hevelius did not regard the fox and the goose to be two separate constellations, but later the stars were divided into a separate Anser and Vulpecula. Today, they have been merged again under the name of the fox, but the goose is remembered by the name of the star α Vulpeculae:
Anser.
See also
*
3C 433
*
Vulpecula (Chinese astronomy)
References
Sources
* also available from Princeton University Press, Princeton: .
Footnotes
External links
The Deep Photographic Guide to the Constellations: Vulpecula(Students for the Exploration and Development of Space)
{{DEFAULTSORT:Vulpecula
Northern constellations
Mythological foxes
Constellations listed by Johannes Hevelius