Messier 29 or M29, also known as NGC 6913, is a quite small, bright

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 ...

star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

s just south of the central bright star

Gamma Cygni Gamma Cygni (γ Cygni, abbreviated Gamma Cyg, γ Cyg), officially named Sadr , is a star in the northern constellation of Cygnus, forming the intersection of an asterism of five stars called the Northern Cross. Based upon parallax mea ...

of a northerly zone of the sky, Cygnus. It was discovered by

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 ...

in 1764, and can be seen from

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

by using

binoculars Binoculars or field glasses are two refracting telescopes mounted side-by-side and aligned to point in the same direction, allowing the viewer to use both eyes (binocular vision) when viewing distant objects. Most binoculars are sized to be held ...

. From the solar system's viewpoint it is well within the several degrees of a certain intermittently uniquely bright and dusty plane of the night sky – that of the arms and bulge of the

Milky Way The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye ...

. It is at least many hundreds of light years short of the yardstick distance to the galactic center, as is between 4,000Kenneth Glyn Jones (ed.) ''The Sky Catalogue 2000.0'' and 7,200

light year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s away.Preferred by most sources including Mallas/Kreimer and Burnham, and agreeing with early estimates or R.J. Trumpler 1930 A 1998 popular work gives a value within this range.Kepple, George Robert., Sanner, Glen W.. The Night Sky Observer's Guide: Spring & summer. United States: Willmann-Bell, 1998 at Chapter 42. Cygnus, The Swan The uncertainty is due to poorly known absorption of the cluster's light. Its

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 and ...

greatly is from faint surrounding nebulosity and other foreground

interstellar matter In astronomy, the interstellar medium is the matter and radiation that exist in the space between the star systems in a galaxy. This matter includes gas in ionic, atomic, and molecular form, as well as dust and cosmic rays. It fills interstellar s ...

of this cross-section of the

spiral arm Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''Orion–Cygnus Arm The Orion Arm is a minor spiral arm of the Milky Way Galaxy that is across and approximately in length, containing the Solar System, including Earth. It is also referred to by its full name, the Orion–Cygnus Arm, as well as Local Arm, Orion ...

, which is our local arm). According to the Sky Catalogue, M29 is included in the Cygnus OB1 association, and the radial velocity component of three-dimensional motion, by default factoring in the solar system's current trajectory, is one of approaching at 28 km/s (noted, thus, as negative). Its age is estimated at 10 million years, as its five hottest stars are all

giants A giant is a being of human appearance, sometimes of prodigious size and strength, common in folklore. Giant(s) or The Giant(s) may also refer to: Mythology and religion *Giants (Greek mythology) *Jötunn, a Germanic term often translated as 'gi ...

of spectral class B0. Kepple and his associates give the apparent brightness of the brightest star as eighth magnitude of in the mid-wavelength (and frequency) "visual" band. The cluster's

absolute magnitude Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse Logarithmic scale, logarithmic Magnitude (astronomy), astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent mag ...

is estimated at −8.2, a luminosity of 160,000 suns (). The linear diameter was estimated at only 11 light years. Its Trumpler class is III,3,p,n (as it is associated with nebulosity), although Götz gives, differently, II,3,m, and Kepple gives I,2,m,n. The Sky Catalogue lists it with 50 member stars; earlier Becvar estimated 20 members. North of 47 degrees north, the cluster is for part or all of the day above the horizon. It can be made out in

in a good sky. In telescopes, lowest powers are best. The brightest of its stars form a "stubby

dipper Dippers are members of the genus ''Cinclus'' in the bird family Cinclidae, so-called because of their bobbing or dipping movements. They are unique among passerines for their ability to dive and swim underwater. Taxonomy The genus ''Cinclus'' ...

", per Mallas. The four brightest stars form a quadrilateral, and another set a small triangle just north of the northernmost of the four. It is often known as the "

cooling tower A cooling tower is a device that rejects waste heat to the atmosphere through the cooling of a coolant stream, usually a water stream to a lower temperature. Cooling towers may either use the evaporation of water to remove process heat and ...

" due to its resemblance to the hyperboloid-shaped structures. A few fainter stars are around them, but the cluster appears quite isolated, especially in smaller telescopes. In photographs, many faint Milky Way background stars appear. Messier 29 can be found quite easily as it is about 1.7 degrees south of Gamma or 37 Cygni (Sadr). Angularly close, and almost certainly nearby in space, is diffuse nebulosity. The especially hot binary Wolf-Rayet star

WR 143 WR may refer to: Arts and media * '' W.R.: Mysteries of the Organism'', a Serbian film, * Wikipedia Review, an Internet forum for the discussion of Wikimedia projects, particularly the English Wikipedia. *Willie Revillame, a Philippine TV host * ...

(WC4+Be) (HD 195177) can be found near this cluster.

References and footnotes

External links

Messier 29
RGB Image

LRGB image – 2 hrs total exposure * * {{Sky, 20, 23, 56, , 38, 31.4, 00, 4000 Messier 029 Messier 029 029 Messier 029 Orion–Cygnus Arm 17640729

See also

References and footnotes

External links