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

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, an ...

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

galaxy. It is situated within the Carina Nebula 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 ra ...

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

the tropics The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

southward,

Eta Carinae Eta Carinae (η Carinae, abbreviated to η Car), formerly known as Eta 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 distant in t ...

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 fil ...

, 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 (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation ...

wavelengths.

Carina OB1

Trumpler 16 and Trumpler 14 are the most prominent star clusters in , a giant stellar association in the

Carina spiral arm Carina may refer to: Places Australia * Carina, Queensland, a suburb in Brisbane * Carina Heights, Queensland, a suburb in Brisbane * Carina, Victoria, a locality in Mildura Serbia * Carina, Osečina, a village in the Kolubara District Pe ...

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

. 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 The Seven Sisters, Messier 45 and other names by different cultures, is an asterism and an open star cluster containing middle-aged, hot B-type stars in the north-west of the constellation Taurus. At a distance ...

. In a few million years, after the brightest stars have exploded as supernovae, 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'' space telescope. The catalogues are released in stages that will contain increasing amounts of information; the early releases also miss some stars, espec ...

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 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, NGC 3324, IC 2581, Trumpler 14, T ...

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 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 cluster. T ...

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

References

External links