Vulpecula
Encyclopedia
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).
, a magnitude
4.44m red giant
at a distance of 297 light-year
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.
In 1967, the first pulsar
, PSR B1919+21, was discovered in Vulpecula by Antony Hewish
and Jocelyn Bell, in Cambridge. While they were searching for scintillation of radio signals of quasar
s, they observed pulses which repeated with a period of 1.3373 second
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
. 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
, the closest extrasolar planet currently being studied by the Spitzer Space Telescope
. On 12 July 2007 the Financial Times (London) reported that the chemical signature of water vapour was detected in the atmosphere of this planet. 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.
(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 6 arcminutes in diameter. 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.
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
.
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
in the northern sky. Its name is Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
for "little fox
Fox
Fox is a common name for many species of omnivorous mammals belonging to the Canidae family. Foxes are small to medium-sized canids , characterized by possessing a long narrow snout, and a bushy tail .Members of about 37 species are referred to as foxes, of which only 12 species actually belong to...
", 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
Summer Triangle
The Summer Triangle is an astronomical asterism involving an imaginary triangle drawn on the northern hemisphere's celestial sphere, with its defining vertices at Altair, Deneb, and Vega, being the brightest stars in the three constellations of Aquila, Cygnus, and Lyra.The English term was...
(an asterism
Asterism (astronomy)
In astronomy, an asterism is a pattern of stars recognized on Earth's night sky. It may form part of an official constellation, or be composed of stars from more than one. Like constellations, asterisms are in most cases composed of stars which, while they are visible in the same general direction,...
consisting of the bright stars Deneb
Deneb
Deneb is the brightest star in the constellation Cygnus and one of the vertices of the Summer Triangle. It is the 19th brightest star in the night sky, with an apparent magnitude of 1.25. A blue-white supergiant, Deneb is also one of the most luminous nearby stars...
, Vega
Vega
Vega is the brightest star in the constellation Lyra, the fifth brightest star in the night sky and the second brightest star in the northern celestial hemisphere, after Arcturus...
and Altair).
Stars
There are no stars brighter than 4th magnitude in this constellation. The brightest star in Vulpecula is α VulpeculaeAlpha Vulpeculae
Alpha Vulpeculae is the brightest star in the constellation Vulpecula. It has a traditional name, variously represented as Lukida, Lucida Anseris, or Anser, a tradition kept from when the constellation had the name Vulpecula et Anser 'the fox and the goose'.Alpha Vulpeculae is a red giant of...
, a magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
4.44m red giant
Red giant
A red giant is a luminous giant star of low or intermediate mass in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius immense and the surface temperature low, somewhere from 5,000 K and lower...
at a distance of 297 light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...
s. The star is an optical binary
Double star
In observational astronomy, a double star is a pair of stars that appear close to each other in the sky as seen from Earth when viewed through an optical telescope. This can happen either because the pair forms a binary star, i.e...
(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.
In 1967, the first pulsar
Pulsar
A pulsar is a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation. The radiation can only be observed when the beam of emission is pointing towards the Earth. This is called the lighthouse effect and gives rise to the pulsed nature that gives pulsars their name...
, PSR B1919+21, was discovered in Vulpecula by Antony Hewish
Antony Hewish
Antony Hewish FRS is a British radio astronomer who won the Nobel Prize for Physics in 1974 for his work on the development of radio aperture synthesis and its role in the discovery of pulsars...
and Jocelyn Bell, in Cambridge. While they were searching for scintillation of radio signals of quasar
Quasar
A quasi-stellar radio source is a very energetic and distant active galactic nucleus. Quasars are extremely luminous and were first identified as being high redshift sources of electromagnetic energy, including radio waves and visible light, that were point-like, similar to stars, rather than...
s, they observed pulses which repeated with a period of 1.3373 second
Second
The second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock....
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
Solar time
Solar time is a reckoning of the passage of time based on the Sun's position in the sky. The fundamental unit of solar time is the day. Two types of solar time are apparent solar time and mean solar time .-Introduction:...
. This anomaly was finally identified as the signal of a rapidly rotating neutron star
Neutron star
A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type Ic supernova event. Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and with a slightly larger...
. Fifteen years after the first pulsar was discovered, the first millisecond pulsar
Millisecond pulsar
A millisecond pulsar is a pulsar with a rotational period in the range of about 1-10 milliseconds. Millisecond pulsars have been detected in the radio, X-ray, and gamma ray portions of the electromagnetic spectrum. The origin of millisecond pulsars is still unknown...
, PSR B1937+21
PSR B1937+21
PSR B1937+21 is a pulsar located in the constellation Vulpecula a few degrees in the sky away from the first discovered pulsar, PSR B1919+21. The name PSR B1937+21 is derived from the word "pulsar" and the declination and right ascension at which it is located, with the "B" indicating that the...
, 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
HD 189733 b
HD 189733 b is an extrasolar planet approximately 63 light-years away in the constellation of Vulpecula . The planet was discovered orbiting the star HD 189733 on October 5, 2005, when astronomers in France observed the planet transiting across the face of the star. The planet is classified as a...
, the closest extrasolar planet currently being studied by the Spitzer Space Telescope
Spitzer Space Telescope
The Spitzer Space Telescope , formerly the Space Infrared Telescope Facility is an infrared space observatory launched in 2003...
. On 12 July 2007 the Financial Times (London) reported that the chemical signature of water vapour was detected in the atmosphere of this planet. 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.
Deep sky objects
Two well-known deep sky objects can be found in Vulpecula. The Dumbbell NebulaDumbbell Nebula
The Dumbbell Nebula is a planetary nebula in the constellation Vulpecula, at a distance of about 1,360 light years....
(M27), is a large, bright planetary nebula
Planetary nebula
A planetary nebula is an emission nebula consisting of an expanding glowing shell of ionized gas ejected during the asymptotic giant branch phase of certain types of stars late in their life...
which was discovered by the French astronomer Charles Messier
Charles Messier
Charles Messier was a French astronomer most notable for publishing an astronomical catalogue consisting of deep sky objects such as nebulae and star clusters that came to be known as the 110 "Messier objects"...
in 1764 as the very first object of its kind. It can be seen with good binoculars
Binoculars
Binoculars, field glasses or binocular telescopes are a pair of identical or mirror-symmetrical telescopes mounted side-by-side and aligned to point accurately in the same direction, allowing the viewer to use both eyes when viewing distant objects...
in a dark sky location, appearing as a dimly glowing disk approximately 6 arcminutes in diameter. A telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
reveals its double-lobed shape, similar to that of an hourglass. Brocchi's Cluster
Brocchi's Cluster
Collinder 399 is a random grouping of stars located in the constellation Vulpecula near the border with Sagitta. Collinder 399 is known as Al Sufi's Cluster or Brocchi's Cluster...
(Collinder 399) is an asterism
Asterism (astronomy)
In astronomy, an asterism is a pattern of stars recognized on Earth's night sky. It may form part of an official constellation, or be composed of stars from more than one. Like constellations, asterisms are in most cases composed of stars which, while they are visible in the same general direction,...
formerly thought to be an open cluster
Open cluster
An open cluster is a group of up 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 many more are thought to exist...
. It is also called "the Coathanger" because of its distinctive star pattern when viewed with binoculars or a low power telescope.
History
Johannes Hevelius
Johannes Hevelius Some sources refer to Hevelius as Polish:Some sources refer to Hevelius as German:*Encyplopedia Britannica * of the Royal Society was a councilor and mayor of Danzig , Pomeranian Voivodeship, in the Polish-Lithuanian Commonwealth...
created Vulpecula. It was originally known as Vulpecula cum ansere ("the little fox with the goose
Goose
The word goose is the English name for a group of waterfowl, belonging to the family Anatidae. This family also includes swans, most of which are larger than true geese, and ducks, which are smaller....
" 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
Alpha Vulpeculae
Alpha Vulpeculae is the brightest star in the constellation Vulpecula. It has a traditional name, variously represented as Lukida, Lucida Anseris, or Anser, a tradition kept from when the constellation had the name Vulpecula et Anser 'the fox and the goose'.Alpha Vulpeculae is a red giant of...
.
External links
- The Deep Photographic Guide to the Constellations: Vulpecula
- Vulpecula page at SEDS (Students for the Exploration and Development of Space)
- M-27 page at SEDS
- Star Tales - Vulpecula