HD 93205, or V560 Carinae, is a

binary Binary may refer to: Science and technology Mathematics * Binary number, a representation of numbers using only two digits (0 and 1) * Binary function, a function that takes two arguments * Binary operation, a mathematical operation that t ...

stellar system, in the Carina Nebula (NGC 3372) in the constellation

Carina 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 ...

. It consists of two massive O-stars that revolve around each other in 6 days. The more massive member of the pair is an O3.5 main sequence star. The spectrum shows some ionised nitrogen and helium emission lines, indicating some mixing of fusion products to the surface and a strong

stellar wind A stellar wind is a flow of gas ejected from the upper atmosphere of a star. It is distinguished from the bipolar outflows characteristic of young stars by being less collimated, although stellar winds are not generally spherically symmetric. D ...

. The mass calculated from apsidal motion of the orbits is . This is somewhat lower than expected from evolutionary modelling of a star with its observed parameters. The less massive member is an O8 main sequence star of approximately . It moves in its orbit at a speed of over 300 km/s and is considered to be a relativistic binary, which causes the apses of the orbit to change in a predictable way. The closeness of the two stars causes them to become deformed, and this means that the observed brightness of the system varies slightly every six days during its orbit. The total amplitude of the variation is only 0.02 magnitudes. It is generally considered as a member of the

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 ...

Trumpler 16 Trumpler 16 (''Tr 16'') is a massive open cluster that is home to some of the most luminous stars in the Milky Way galaxy. It is situated within the Carina Nebula complex in the Carina–Sagittarius Arm, located approximately from Earth. The c ...

. Among its neighbors are some of the most massive and luminous stars in the galaxy, like

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 ...

HD 93250 HD 93250 is a highly luminous hot blue binary star in the Carina Nebula in the constellation Carina. Location HD 93250 is one of the brightest stars in the region of the Carina Nebula. It is only 7.5 arc-minutes from the famous ...

and the binary

HD 93129 HD 93129 is a triple star system in the Carina Nebula, with all three components being hot O class stars amongst the most luminous stars in the Milky Way. It is the dominant member of the Trumpler 14 star cluster, a young star cluste ...

. It lies five

arc-minute A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The n ...

s from Eta Carinae.

References

{{DEFAULTSORT:HD 93205 Carina Nebula O-type main-sequence stars Spectroscopic binaries Carinae, V560 Durchmusterung objects 093205 Carina (constellation) Emission-line stars Rotating ellipsoidal variables