C/2005 EL173 LONEOS
more info
C/2005 EL173 was discovered on 8 March 2005 by the LONEOS as an apparently asteroidal object in a retrograde orbit and semimajor axis of 36 au [MPEC 2005-F48, 2005 March 29]. Therefore it was initially classified as cubewano or scattered disc object in MPC. Its cometary apperance was reported by A. Fitzsimmons on 10 May 2005. C/2005 EL173 was observed until mid-November 2008.

This comet made its closest approach to the Earth on 4 January 2007 (3.310 au), two months before perihelion passage.

Solutions given here are based on data spanning over 3.7 yr in a range of heliocentric distances: 7.12 au – 3.886 au (perihelion) – 6.45 au.

NG orbit using full data-arc is determinable.

This Oort spike comet suffers rather slight planetary perturbations during its passage through the planetary system; however, these perturbations leas to escape this comet from the planetary zone on a hyperbolic orbit.

See also Królikowska and Dones 2023, Królikowska and Dybczyński 2017,and Królikowska 2014.
solution description
number of observations 317
data interval 2005 03 03 – 2008 11 17
data type perihelion within the observation arc (FULL)
data arc selection entire data set (STD)
range of heliocentric distances 7.12 au – 3.89 au (perihelion) – 6.45 au
type of model of motion NS - non-gravitational orbits for standard g(r)
data weighting YES
number of residuals 632
RMS [arcseconds] 0.36
orbit quality class 1a+
orbital elements (heliocentric ecliptic J2000)
Epoch 2007 03 01
perihelion date 2007 03 05.87190600 ± 0.00018000
perihelion distance [au] 3.88631166 ± 0.00000283
eccentricity 1.00333283 ± 0.00000329
argument of perihelion [°] 261.493679 ± 0.000034
ascending node [°] 344.796425 ± 0.000009
inclination [°] 130.67961 ± 0.000008
reciprocal semi-major axis [10-6 au-1] -857.58 ± 0.84
Upper panel: Time distribution of positional observations with corresponding heliocentric (red curve) and geocentric (green curve) distance at which they were taken. The horizontal dotted line shows the perihelion distance for a given comet whereas vertical dotted line — the moment of perihelion passage.
Middle panel(s): O-C diagram for a given solution (sometimes in comparison to another solution available in CODE), where residuals in right ascension are shown using magenta dots and in declination by blue open circles.
Lowest panel: Relative weights for a given data set(s).
non-gravitational parameters
A1 [10-8au/day2] 6602 ± 773
A2 [10-8au/day2] -7175 ± 496
A3 [10-8au/day2] 0 (assumed)
m -2.15
n 5.093
k -4.6142
r0 [au] 2.808
α 0.1113