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, and ...

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 ey ...

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 Wa ...

complex in the Carina–Sagittarius Arm, located approximately from Earth. The cluster has one star visible to the naked eye from the tropics southward, Eta Carinae.

Description

Its most luminous members are and , with both having

luminosities Luminosity is an absolute measure of radiated electromagnetic power (light), the radiant power emitted by a light-emitting object over time. In astronomy, luminosity is the total amount of electromagnetic energy emitted per unit of time by a st ...

several million times that of the Sun, and there are three other extreme stars with O3 spectral classes. Both and are binaries, 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 radiati ...

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 ...

. 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 th ...

. 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, especia ...

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

References

External links