2008 LC18

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2008 LC18
Discovery
Discovered by Sheppard & Trujillo
Discovery date 2008-06-07
Orbital characteristics[1][2]
Epoch July 23, 2010
Aphelion 32.5 AU
Perihelion 27.4 AU
Semi-major axis 29.91 AU
Eccentricity 0.085
Orbital period 163.6 yr
Mean anomaly 174°
Inclination 27.584°
Longitude of ascending node 88.521°
Argument of perihelion
Physical characteristics
Absolute magnitude (H) 8.4[1]

2008 LC18 is a Neptune trojan discovered on June 7, 2008, by Scott S. Sheppard and Chad Trujillo using the Subaru telescope.[3] It was the seventh such object to be discovered, as well as the first to be found in the region of the trailing L5 Lagrangian point about 60 degrees behind Neptune.[3][4] Like all Neptune trojans, 2008 LC18 has the same orbital period as Neptune;[4] i.e., it and Neptune are in a 1:1 orbital resonance.

2008 LC18 has an inclination of 27.5 degrees.[1] As of August 2010, this is the second highest inclination of any known Neptune trojan.[3][4]

With an absolute magnitude of 8.4,[1][4] it has a diameter estimated at ~100 km.[3]

The discovery of Neptune's L5 trojans has been impeded by the fact that they are in a region of space along the line-of-sight to the center of our galaxy, an area of the sky crowded with stars. 2008 LC18 was found in a location where background stars are obscured by a dust cloud.[3][5] The discovery of one Neptune L5 trojan in a searched area of 19 square degrees suggests that there may be 150 Neptune L5 trojans with a diameter greater than ~80 km (24th magnitude), similar to the estimate of such objects in Neptune's L4 swarm.[3]

2008 LC18 will not be close enough for investigation by the New Horizons spacecraft when it crosses Neptune's L5 region en route to Pluto in 2013–2014, but its discovery shows that other, more accessible Neptune trojans could potentially be found before that time.[6] 2008 LC18 will cross the ecliptic plane in 2011.

References[edit]

  1. ^ a b c d "JPL Small-Body Database Browser: 2008 LC18". Retrieved 2010-08-13. 
  2. ^ AstDys-2 about 2008 LC18
  3. ^ a b c d e f Sheppard, Scott S.; Trujillo, Chadwick A. (2010). "Detection of a Trailing (L5) Neptune Trojan". Science 329 (5997): 1304. Bibcode:2010Sci...329.1304S. doi:10.1126/science.1189666. PMID 20705814. 
  4. ^ a b c d "List Of Neptune Trojans". Minor Planet Center. Retrieved 2008-05-08. 
  5. ^ Lakdawalla, Emily (2010-08-13). "2008 LC15, the first Trojan asteroid discovered in Neptune's L5 point". The Planetary Society. Archived from the original on 17 August 2010. Retrieved 2010-08-14. 
  6. ^ "Reaching the Mid-Mission Milestone on the Way to Pluto!". New Horizons : The PI's Perspective. 2010-10-18. Retrieved 2010-10-18. 

External links[edit]