Editing Messier 3 (section)

== Visibility ==
[[File:Messier 3 - Globular cluster.png|thumb|left|Messier 3 by amateur astrophotographer Anthony MICHEL<ref>{{cite web|title=Messier 3 - Globular cluster |url=https://app.astrobin.com/i/i4a8w4}}<!-- auto-translated from French by Module:CS1 translator --></ref>]]

Many amateur astronomers consider it one of the finest northern globular clusters, following only [[Messier 13]].<ref name=thompson_thompson2007/> M3 has an [[apparent magnitude]] of 6.2,<ref name="simbad"/> making it a difficult [[naked eye]] target<ref name=OMeara1998 /> even with [[Bortle Dark-Sky Scale|dark conditions]] with [[averted vision]]. However, with a moderate-sized telescope, the cluster can be seen as a cloudy smudge even in severely light-polluted skies, and can be further defined in darker conditions. It can be found by looking almost exactly halfway along the north-west line that would join [[Arcturus]] (α Boötis) to [[Cor Caroli]] (α Canum Venaticorum). Using a telescope with a {{Convert|25|cm|in|abbr=on}} [[aperture]], the cluster has a bright core with a diameter of about 6&nbsp;[[arcminute]]s and spans a total of double that.<ref name=thompson_thompson2007/>