588 Achilles

Infobox Planet | discovery=yes | physical_characteristics = yes | bgcolour=#FFFFC0
name=588 Achilles
discoverer=Max Wolf
discovered=February 22, 1906
alt_names=1906 TG
mp_category=Trojan asteroid
epoch=October 22, 2004 (JD 2453300.5)
semimajor=776.669 Gm (5.192 AU)
perihelion=662.395 Gm (4.428 AU)
aphelion=890.944 Gm (5.956 AU)
eccentricity=0.147
period=4320.803 d (11.83 a)
inclination=10.324°
asc_node=316.583°
arg_peri=132.770°
mean_anomaly=157.779°
avg_speed=13.00 km/s
dimensions=135.5 km
mass=2.6×10¹⁸ kg
density=2.0 g/cm³
surface_grav=0.0379 m/s²
escape_velocity=0.0716 km/s
rotation=>0.5 d [http://www.astrosurf.com/aude-old/map_files/AstVarMAP01-2003.htm ¹]
spectral_type= D
abs_magnitude=8.67
albedo=0.0328 [http://www.psi.edu/pds/archive/astdata/ALBEDOS/albedos.tab ²]
single_temperature=~124 K

588 Achilles is an asteroid discovered on February 22, 1906 by the German astronomer Max Wolf. It was the first of the Trojan asteroids to be discovered, and is named after Achilles, the fictional hero from the Iliad. It orbits in the L₄ Lagrangian point of the Sun-Jupiter system. After a few such asteroids were discovered, the rule was established that the L₄ point was the "Greek camp", while the L₅ point was the "Trojan camp", though not before each camp had acquired a "spy" (624 Hektor in the Greek camp and 617 Patroclus in the Trojan camp ).

External links

* [http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=588;orb=1 Orbital simulation] from JPL (Java) / [http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr=588 Ephemeris]