Stellar stream

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A stellar stream is an association of stars orbiting a galaxy that was once a globular cluster or dwarf galaxy that has now been torn apart and stretched out along its orbit by tidal forces.

[edit] List of stellar streams

Known streams in the Milky Way^[1]

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
	Globular cluster				2007[2]
	Globular cluster				2007[2]
	Defunct dwarf galaxy				2007[2]

Known streams in the Andromeda Galaxy

Name	Origin	Mass (Solar masses)	Length (light years)	Composition	Discovery year

[edit] References