The Wild Duck Cluster (also known as Messier 11, or NGC 6705) is an

open cluster An open cluster is a type of star cluster made 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 ...

of stars in the constellation Scutum (the Shield). It was discovered by Gottfried Kirch in 1681.

Charles Messier Charles Messier (; 26 June 1730 – 12 April 1817) was a French astronomer. He published an astronomical catalogue consisting of 110 nebulae and star clusters, which came to be known as the ''Messier objects''. Messier's purpose f ...

included it in his catalogue of diffuse objects in 1764. Its popular name derives from the brighter stars forming a triangle which could resemble a flying flock of

duck Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a fo ...

s (or, from other angles, one swimming duck). The cluster is located just to the east of the Scutum Star Cloud midpoint. The Wild Duck Cluster is one of the richest and most compact of the known open clusters. It is one of the most massive open clusters known, and it has been extensively studied. Its age has been estimated to about 316 million years. The core radius is while the tidal radius is . Estimates for the cluster's mass range from to , depending on the method chosen. The brightest cluster member is visual magnitude 8, and it has 870 members of at least magnitude 16.5. It has an integrated

absolute magnitude Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse logarithmic astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent magnitude that the object would have if it we ...

of –6.5, and a visual

extinction Extinction is the termination of a kind of organism or of a group of kinds ( taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed ...

of 1.3. The cluster is metal-rich with an iron abundance of e/H= . Despite its youth, it shows an enhancement of

Alpha process The alpha process, also known as the alpha ladder, is one of two classes of nuclear fusion reactions by which stars convert helium into heavier elements, the other being the triple-alpha process. The triple-alpha process consumes only helium, an ...

elements. Possibly this is due to an enhancement of its birth

molecular cloud A molecular cloud, sometimes called a stellar nursery (if star formation is occurring within), is a type of interstellar cloud, the density and size of which permit absorption nebulae, the formation of molecules (most commonly molecular hydroge ...

by a nearby

Type II supernova A Type II supernova (plural: ''supernovae'' or ''supernovas'') results from the rapid collapse and violent explosion of a massive star. A star must have at least 8 times, but no more than 40 to 50 times, the mass of the Sun () to undergo this ...

explosion. At least nine

variable star A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as e ...

members have been identified with high probability, plus 29 lower probability members. The former include two

eclipsing binary A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in ...

star systems. The cluster is located from the

Galactic Center The Galactic Center or Galactic Centre is the rotational center, the barycenter, of the Milky Way galaxy. Its central massive object is a supermassive black hole of about 4 million solar masses, which is called Sagittarius A*, a compact ...

, close to the

galactic plane The galactic plane is the plane on which the majority of a disk-shaped galaxy's mass lies. The directions perpendicular to the galactic plane point to the galactic poles. In actual usage, the terms ''galactic plane'' and ''galactic poles'' usual ...

, and is not far from its birthplace.

Gallery

Wild cosmic ducks Messier 11.jpg, A portion of M11, imaged by the

Hubble Space Telescope The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most ver ...

. Eso1430a.jpg, The blue stars in the centre of the image are the young, hot stars of the cluster. Messier11.jpg, M11 is visible with binoculars in the constellation of Scutum.

References

External links

Messier 11, SEDS Messier pages

Messier 11, Wild Duck Cluster

* {{DEFAULTSORT:Wild Duck Cluster Open clusters Carina–Sagittarius Arm Wild Duck Cluster NGC objects Scutum (constellation) ?

Gallery

See also

References

External links