Stellar stream
From Wikipedia, the free encyclopedia
A stellar stream is an association of stars orbiting a galaxy that were once a globular cluster or dwarf galaxy that has now been torn apart and stretched out along its orbit by tidal forces.
| Name | Origin | Mass (Solar masses) |
Length (light years) |
Composition | Discovery year |
|---|---|---|---|---|---|
| Arcturus stream | Defunct dwarf galaxy | Unknown | Unknown | Old stars deficient in heavy elements | 1971 |
| Magellanic stream | Large and Small Magellanic Clouds | 200 million | 1 million | Hydrogen gas | 1972 |
| Sagittarius stream | Sagittarius Dwarf Elliptical Galaxy | 100 million | 1 million | Wide variety of stars | 1994 |
| Helmi stream | Defunct dwarf galaxy | 10 to 100 million | Several complete loops around the Milky Way | Old stars deficient in heavy elements | 1999 |
| Palomar 5 stream | Globular cluster Palomar 5 | 5000 | 30,000 | Old stars | 2001 |
| Virgo stream | defunct dwarf galaxy | 30,000 | 2001 | ||
| Monoceros ring | Canis Major dwarf galaxy | 100 million | 200,000 | Intermediate-age stars | 2002 |
| Anticenter stream | Defunct dwarf galaxy | Unknown | 30,000 | Old stars | 2006 |
| NGC 5466 stream | Globular cluster NGC 5466 | 10,000 | 60,000 | Very old stars | 2006 |
| Orphan stream | Ursa Major II dwarf galaxy | 100,000 | 20,000 | Old stars | 2006 |
[edit] References
- ^ Ibata, Rodrigo; Gibson, Brad (April 2007). "The Ghosts of Galaxies Past". Scientific American: 40-45.
