Editing 588 Achilles (section)

=== Photometry ===

Achilles's [[rotation period]] of 7.3 hours is somewhat shorter than that of most other large Jupiter trojans but close to that of [[911&nbsp;Agamemnon]], [[3451&nbsp;Mentor]] and [[3317&nbsp;Paris]], which are similar in size ''(see table below)''. Its low brightness amplitude is indicative of a rather spherical shape.<ref name="lcdb" /> From July 2007 until September 2008, coordinated [[Photometry (astronomy)|photometric]] observations were carried out by astronomers at [[Simeiz Observatory|Simeiz]] (Crimea), [[Rozhen Observatory|Rozhen]] (Bulgaria), Maidanak (Uzbekistan) and [[IAU code#101|Kharkiv]] (Ukraine) observatories.<ref name="Shevchenko-2009a" /><ref name="Stephens-2010c" /> Analysis of the obtained [[lightcurve]]s determined a period of {{val|7.306|0.002}} hours with a brightness amplitude of 0.02–0.11 [[Magnitude (astronomy)|magnitude]] ({{small|[[LCDB quality code|U=3/3/3/3]]}}).<ref name="lcdb" /> Alternative period determinations by Cláudia Angeli (7.0&nbsp;h), [[Robert D. Stephens|Robert Stephens]] (7.312&nbsp;h), [[Stefano Mottola]] (7.32&nbsp;h) and [[Vincenzo Zappalà]] (12&nbsp;h) are mostly in good agreement ({{small|[[LCDB quality code|U=1/3-/3/1]]}}).<ref name="lcdb" /><ref name="Angeli-1999" /><ref name="Stephens-2010c" /><ref name="Mottola-2011" /><ref name="Zappala-1989" />