Vulpecula is a faint constellation in the northern sky. Its name is Latin 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 at an approximate distance of 291
. The star is an
double star (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, PSR B1919+21, was discovered in Vulpecula by Jocelyn Bell, supervised by Antony Hewish, in Cambridge. While they were searching for scintillation of radio signals of , they observed pulses which repeated with a period of 1.3373 .
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.
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 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. 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
dust lane disk with a diameter of 3700 light-years; there is a supermassive black hole with a mass of 300 million solar masses in its
galactic nucleus. Astronomers surmise that the disk is the remnant of a smaller galaxy that
galactic merger with NGC 7052. Jets can be seen emanating from the galaxy, and it has very strong
radio spectrum. 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 star and over 800 young stellar objects. It lies in the galactic plane, at a distance of about 2300
parsec. 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:
Alpha Vulpeculae.
See also
-
3C 433
-
Vulpecula (Chinese astronomy)
Sources
-
also available from Princeton University Press, Princeton: .
Footnotes
External links
