
Fimbulthul is a tidal
stellar stream
In astronomy, stellar kinematics is the observational study or measurement of the kinematics or motions of stars through space.
Stellar kinematics encompasses the measurement of stellar velocities in the Milky Way and its satellites as well as t ...
torn off from
Omega Centauri
Omega Centauri (ω Cen, NGC 5139, or Caldwell 80) is a globular cluster in the constellation of Centaurus that was first identified as a non-stellar object by Edmond Halley in 1677. Located at a distance of , it is the largest-known globular clus ...
, the largest
globular cluster
A globular cluster is a spheroidal conglomeration of stars. Globular clusters are bound together by gravity, with a higher concentration of stars towards their centers. They can contain anywhere from tens of thousands to many millions of memb ...
of our
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. The stream contains 309 known stars stretching over 18° in the constellations of
Hydra and
Centaurus
Centaurus is a bright constellation in the southern sky. One of the largest constellations, Centaurus was included among the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. I ...
, matching the same age as the globular cluster. Omega Centauri is considered the nucleus of a
dwarf galaxy
A dwarf galaxy is a small galaxy composed of about 1000 up to several billion stars, as compared to the Milky Way's 200–400 billion stars. The Large Magellanic Cloud, which closely orbits the Milky Way and contains over 30 billion stars, is s ...
that merged with the Milky Way.
The stream was discovered in the
Gaia DR2
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 ...
star database that determined the direction, distances and motion of over one billion stars.
Catastrophic tale of the most massive globular cluster of the Milky Way
Khyati Malhan, Apr 23, 2019
The name Fimbulthul is a river in Norse mythology
Norse, Nordic, or Scandinavian mythology is the body of myths belonging to the North Germanic peoples, stemming from Old Norse religion and continuing after the Christianization of Scandinavia, and into the Nordic folklore of the modern peri ...
.
See also
* List of stellar streams
This is a list of stellar streams. 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. An exception in the ...
References
Identification of the long stellar stream of the prototypical massive globular cluster ω Centauri
Nature Astronomy (2019)
**
Preprint at arxiv.org
Rodrigo Ibata, Michele Bellazzini, Khyati Malhan, Nicolas Martin, Paolo Bianchini, 2019
The Streams of the Gaping Abyss: A population of entangled stellar streams surrounding the Inner Galaxy
Rodrigo Ibata, Khyati Malhan, Nicolas Martin, 2019
External links
Gaia: The sky is littered with undigested galaxies
Omega Centauri's lost stars
Omega Centauri’s lost stars
Milky Way
Milky Way Subgroup
Stellar streams
{{Spiral-galaxy-stub