Английская Википедия:Helmi stream

Материал из Онлайн справочника
Перейти к навигацииПерейти к поиску

Шаблон:Short description The Helmi Stream is a stellar stream of the Milky Way galaxy. It started as a dwarf galaxy, now absorbed by the Milky Way as a stream. It was discovered in 1999, is formed of old stars deficient in heavy elements, and has a mass of 10 to 100 million solar masses. It was absorbed by the Milky Way some 6 to 9 billion years ago.[1]

The stream was named after Amina Helmi, who discovered this stellar stream after noticing this group of stars all moving at the same speed and in the same direction.[2][3] The Helmi Stream discovery affirmed theories that the merging of galaxies played a significant role in creating the giant structures of the Milky Way galaxy.[2]

Extragalactic planet

The Helmi stream was home to the first planet purportedly of extragalactic origin, orbiting the star HIP 13044.[1] Further analysis of radial velocity data failed to confirm the discovery.[4]

See also

References

Шаблон:Reflist

Шаблон:Use dmy dates


Шаблон:Star-cluster-stub Шаблон:Spiral-galaxy-stub