Trumpler 16 (''Tr 16'') is a massive

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

that is home to some of the most luminous stars in the

Milky Way The Milky Way or Milky Way Galaxy is the galaxy that includes the Solar System, with the name describing the #Appearance, galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars in other arms of the galax ...

galaxy. It is situated within the

Carina Nebula The Carina Nebula or Eta Carinae Nebula (catalogued as NGC 3372; also known as the Great Carina Nebula) is a large, complex area of bright and dark nebulosity in the constellation Carina, located in the Carina–Sagittarius Arm of the Milky W ...

complex in the

Carina–Sagittarius Arm The Carina–Sagittarius Arm (also known as the Sagittarius Arm or Sagittarius–Carina Arm, labeled -I) is generally thought to be a minor spiral arm of the Milky Way galaxy. Each spiral arm is a long, diffuse curving streamer of stars that radia ...

, located approximately from Earth. The cluster has one star visible to the naked eye from the tropics southward,

Eta Carinae η Carinae (Eta Carinae, abbreviated to η Car), formerly known as η Argus, is a stellar system containing at least two stars with a combined luminosity greater than five million times that of the Sun, located around ...

Description

Its most luminous members are and , with both having luminosities several million times that of the Sun, and there are three other extreme stars with O3 spectral classes. Both and are

binaries A binary file is a computer file that is not a text file. The term "binary file" is often used as a term meaning "non-text file". Many binary file formats contain parts that can be interpreted as text; for example, some computer document files ...

, with the primary stars contributing most of the luminosity, but with companions which are themselves more massive and luminous than most stars. Totalling all wavelengths, is estimated to be the more luminous of the two, 4,600,000 times the Sun's luminosity ( absolute bolometric magnitude −12) compared to at 2,400,000 times the Sun's luminosity (absolute bolometric magnitude −11.2). However, appears by far the brightest object, both because it is brighter in visual wavelengths and because it is embedded in nebulosity which exaggerates the luminosity. is very hot and emits most of its radiation at

ultraviolet Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of ...

wavelengths.

Carina OB1

Trumpler 16 and Trumpler 14 are the most prominent star clusters in , a giant stellar association in the Carina spiral arm. Another cluster within , , is thought to be an extension of appearing visually separated only because of an intervening

dust lane A dust lane consists of relatively dense, obscuring clouds of interstellar dust, observed as a dark swath against the background of brighter object(s), especially a galaxy. These dust lanes can usually be seen in spiral galaxies, such as the M ...

. The spectral types of the stars indicate that formed by a single wave of star formation. Because of the extreme luminosity of the stars formed, their stellar winds push away the clouds of dust, similar to the

Pleiades The Pleiades (), also known as Seven Sisters and Messier 45 (M45), is an Asterism (astronomy), asterism of an open cluster, open star cluster containing young Stellar classification#Class B, B-type stars in the northwest of the constellation Tau ...

. In a few million years, after the brightest stars have exploded as

supernova A supernova (: supernovae or supernovas) is a powerful and luminous explosion of a star. A supernova occurs during the last stellar evolution, evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion ...

e, the cluster will slowly die away. includes most of the stars in the eastern portion of the association.

Gaia Data Release 2

Gaia Data Release 2 The ''Gaia'' catalogues are star catalogues created using the results obtained by ''Gaia (spacecraft), Gaia'' space telescope. The catalogues are released in stages that will contain increasing amounts of information; the early releases also mis ...

provides parallaxes for many stars considered to be members of Trumpler 16. It finds that the four hottest O-class stars in the region have very similar parallaxes with a mean value of . Many of the other supposed members show significantly different parallaxes and may be foreground or background objects. Therefore, the distance of Trumpler 16 is assumed to be around 2,600 pc, significantly further than the accurately-known distance of η Carinae.

Gallery

File:NGC 3372d.jpg,

Carina OB1 Carina OB1 is a giant Stellar kinematics#OB associations, OB association in the Carina Nebula, which is home to some of the most massive and luminous stars in the Milky Way Galaxy. It includes the young star clusters Collinder 228, NGC 3293, N ...

association, with the area of Trumpler 16 indicated File:WR 25 and Tr16-244 region (cropped).jpg, Some of the stars in Tr 16:

WR 25 WR 25 (HD 93162) is a binary star system in the turbulent star-forming region of the Carina Nebula, about 6,800 light-years from Earth. It contains a Wolf-Rayet star and a hot luminous companion and is a member of the Trumpler 16 cluste ...

and ALS 15210 are the brightest and third-brightest respectively in this image, the second-brightest is merely a foreground object.

References

External links

* {{DEFAULTSORT:Trumpler 16 Carina Nebula Open clusters Carina (constellation) Trumpler catalog Star-forming regions