Scientists are finding more and more evidence that galaxies grow via numerous mergers with dwarf galaxies. In 1994, scientists discovered a group of stars moving at the same velocity across the Milky Way, located about 80,000 light years from earth and 60,000 light years from our Milky Way core. This group was the remnant core of what is now called the Sagittarius Dwarf Spheroidal Galaxy (SDSG), the largest cannibalized dwarf galaxy identified within the Milky Way.
Later, starting in 2002, streams of shredded debris from the SDSG were identified in tidal tails known as the Sagittarius Stream. These tails form several loops around the Milky Way, mainly in polar-aligned orbits.
This poster captures all of the major extragalactic objects identified from SDSG, both in the core and in the stream. Each object has been previously uploaded into Astrobin. The objects shown on the poster are:
Core objects:-
M54 globular cluster (possible former SDSG core, 2nd most massive cluster in Milky Way)
- Terzan 7 globular cluster-
Terzan 8 globular cluster-
Arp 2 globular clusterStream objects:-
NGC 5634 globular cluster-
NGC 2419 globular cluster-
Palomar 12 globular cluster-
Whiting 1 globular cluster (youngest GC in Milky Way)
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Berkeley 29 open cluster (most distant OC in Milky Way)
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Saurer 1 open cluster-
BoBn 1 planetary nebulaAll of these objects, and the poster, are contained in my new
Astrobin Sagittarius Dwarf Spheroidal Galaxy Collection.
Most of the information here comes from an excellent article in the October 2021 edition of Sky and Telescope magazine.
If you would like to access all my DSO compilation posters, please click
here.
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