Editing Messier 4 (section)

==Notable stars==
Photographs by the [[Hubble Space Telescope]] in 1995 found [[white dwarf]] stars in M4 that are among the oldest known stars in [[Milky Way Galaxy|our galaxy]]; aged 13 billion years. One has been found to be a [[binary star]] with a pulsar companion, [[PSR B1620−26]] and a [[PSR B1620−26 b|planet]] orbiting it with a mass of 2.5 times that of [[Jupiter mass|Jupiter]] ({{jupiter mass}}).<ref>{{cite news|title=Ancient orbs|url=http://www.spacetelescope.org/images/potw1236a/|access-date=3 September 2012|newspaper=ESA/Hubble Picture of the Week}}</ref> One star in Messier 4 was also found to have much more of the rare light element lithium than expected.<ref>{{cite news|title=A Cluster with a Secret|url=http://www.eso.org/public/news/eso1235/|access-date=5 September 2012|newspaper=ESO Press Release}}</ref>

CX-1 Is located in M4. It is known as a possible millisecond pulsar/neutron star binary. It orbits in 6.31 hours.<ref name="Kaluzny"/>