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Extragalactic astronomy is the branch of astronomy concerned with objects outside our own Milky Way Galaxy. In other words, it is the study of all astronomical objects which are not covered by galactic astronomy.

As instrumentation has improved, more distant objects can now be examined in detail. It is therefore useful to sub-divide this branch into Near-Extragalactic Astronomy and Far-Extragalactic Astronomy. The former deals with objects such as the galaxies of our Local Group, which are close enough to allow very detailed analyses of their contents (e.g. supernova remnants, stellar associations). The latter describes the study of objects sufficiently far away that only the brightest phenomena are observable.

Some topics include:

• Groups and clusters of galaxies
• Quasars
• Radio galaxies
• Supernovae

[edit] See also

• Galaxy color-magnitude diagram
• Galaxy formation and evolution
• Observational cosmology

v • d • e Astronomy Main articles Observational astronomy · History of astronomy · Astrometry · Galactic astronomy · Extragalactic astronomy · Physical cosmology · Outline of astronomy Astronomy portal Methods Radio astronomy · Infrared astronomy · Ultraviolet astronomy · Optical astronomy · X-ray astronomy · Gamma-ray astronomy Selected notable optical telescopes Large Binocular Telescope · Gran Telescopio Canarias · W. M. Keck Observatory  · Hubble Space Telescope List of optical telescopes · Category:Telescopes · Extremely large telescope

v • d • e General subfields within astronomy and astrophysics Cosmology · Extragalactic astronomy · Galactic astronomy · Stellar astronomy · Planetary science · Exoplanetology · Astrogeology · Astrometry · Astrochemistry · Astrobiology  · Astrodynamics

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