Palomar 4 is a
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 membe ...
of the
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 eye. ...
galaxy belonging to the
Palomar Globular Clusters group. It was discovered in 1949 by
Edwin Hubble and again in 1955 by
A. G. Wilson. Based on measurements of the stars from the
Gaia spacecraft
''Gaia'' is a space observatory of the European Space Agency (ESA), launched in 2013 and expected to operate until 2025. The spacecraft is designed for astrometry: measuring the positions, distances and motions of stars with unprecedented preci ...
, it is at least from the Sun.
This star cluster is further away than the
SagDEG satellite galaxy.
Initially it was thought to be 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 so ...
, and it was given the name Ursa Major Dwarf. However, it was later discovered to be a globular cluster.
See also
*
Ursa Major Dwarf
References
External links
*
*
Palomar 04
Palomar 04
Palomar 04
Local Group
UGCA objects
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