Constellation in the northern celestial hemisphere
This article is about the constellation. For the animal with scientific nameTrichosurus vulpecula, seecommon brushtail possum. For the Vul pistol, seePSS Silent Pistol.
Visible at latitudes between +90° and −55°. Best visible at 21:00 (9 p.m.) during the month ofSeptember.
Vulpecula/vʌlˈpɛkjʊlə/ is a faintconstellation in the northern sky. Its name isLatin for "littlefox", although it is commonly known simply as the fox. It was identified in the seventeenth century, and is located in the middle of theSummer Triangle (anasterism consisting of the bright starsDeneb,Vega, andAltair).
There are no stars brighter than 4th magnitude in this constellation. The brightest star in Vulpecula isAlpha Vulpeculae, amagnitude 4.44m[1]red giant[2][3] at an approximate distance of 291light-years. The star is anoptical 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.[4]
23 Vulpeculae is the second brightest star in the constellation.
In 1967, the firstpulsar,PSR B1919+21, was discovered in Vulpecula byJocelyn Bell, supervised byAntony Hewish, inCambridge. While they were searching for scintillation of radio signals ofquasars, they observed pulses which repeated with aperiod of 1.3373seconds.[5] Terrestrial origin of the signal was ruled out because the time it took the object to reappear was asidereal day instead of asolar day. This anomaly was finally identified as the signal of a rapidly rotatingneutron star. Fifteen years after the first pulsar was discovered, the firstmillisecond pulsar,PSR B1937+21, was also discovered in Vulpecula, only a few degrees in the sky away from PSR B1919+21.[6]
Vulpecula is also home toHD 189733 b, one of the closest extrasolar planets studied by the now-retiredSpitzer Space Telescope. On 11 July 2007, a team led byGiovanna 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.[7] 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.
TheDumbbell Nebula (M27), is a large, brightplanetary nebula which was discovered by the French astronomerCharles Messier in 1764 as the very first object of its kind.[12] It can be seen with goodbinoculars in a dark sky location, appearing as a dimly glowing disk approximately 8arcminutes in diameter.[13] The nebula is approximately 9,800 years old.[13] Atelescope reveals its double-lobed shape, similar to that of an hourglass.Brocchi's Cluster (Collinder 399) is anasterism formerly thought to be anopen cluster. It is also called "the Coathanger" because of its distinctive star pattern when viewed with binoculars or a low power telescope.
Planetary nebulaHen 2-437 is located in the constellation of Vulpecula.[14]
NGC 7052 is anelliptical galaxy in Vulpecula at a distance of 214 million light-years from Earth. It has a centraldusty disk with a diameter of 3700 light-years; there is asupermassive black hole with a mass of 300 million solar masses in itsnucleus. Astronomers surmise that the disk is the remnant of a smaller galaxy thatmerged with NGC 7052.Jets can be seen emanating from the galaxy, and it has very strongradio emissions. This means that it is also classified as aradio galaxy.[15]
The eastern part of Vulpecula is occupied by theHercules–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.
Vulpecula contains an OB-association of young stars, called theVulpecula OB-association or Vul OB1. The association contains nearly 100OB-stars and over 800young stellar objects. It lies in the galactic plane, at a distance of about 2300parsec. It contains the emission-line nebulae Sh-86, Sh-87 andSh-88. Vul OB1 has a length of about 100 parsec and is sculpting many pillar-like structures in this region.[16][17]
The constellation, under the full name of "Vulpecula and Anser", can be seen on the bottom of this c. 1825 star map fromUrania's Mirror.
In the late 17th century, the astronomerJohannes Hevelius created Vulpecula. It was originally known asVulpecula cum ansere ("the little fox with thegoose") orVulpecula 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.
Ridpath, Ian; Tirion, Wil (2017).Stars and Planets Guide (5th ed.). London: William Collins.ISBN978-0-008-23927-5. also available from Princeton University Press, Princeton:ISBN978-0-691-17788-5.
^Wilkins, Jamie; Dunn, Robert (2006).300 Astronomical Objects: A Visual Reference to the Universe (1st ed.). Buffalo, New York: Firefly Books.ISBN978-1-55407-175-3.
