C/2013 US10 Catalina
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Comet C/2013 US10 was discovered on 31 October 2013 by R.A. Kowalski (Catalina Sky Survey), that is more than two years before perihelion passage. Later, series of pre-discovery measurements dating back to 2013 August 14 were found. This comet was intensively observed until 7 December 2017.C/2013 US10 had two close approaches to the Earth on 14 August 2015 (1.09 au, two months before perihelion) and on 17 January 2016 (0.725 au, two months after perihelion).

This is a comet with NG effects strongly manifested in positional data fitting. Solutions 'a5' and 'n5' (preferred) are based on data spanning over 4.3 yr in a range of heliocentric distances: 8.92 au – 0.823 au (perihelion) – 8.36 au.

This Oort spike comet suffers moderate planetary perturbations while passing through the planetary system; these perturbations lead to escape the comet from the planetary zone on a hyperbolic orbit (see future barycentric orbits) in all orbital solutions given here except the NG solution based on pre-perihelion leg of orbit; however in this case the radial NG parameter is negative ('solution 'pn'). It is worth pointing out that the comet shows some tiny signs of the influence of NG effects on its orbit on the preperihelion leg at heliocentric distances larger than 3 au (solution 'pc').
solution description
number of observations 5154
data interval 2013 08 14 – 2017 12 07
data type perihelion within the observation arc (FULL)
data arc selection entire data set (STD)
range of heliocentric distances 8.92 au – 0.82 au (perihelion) – 8.36 au
type of model of motion NS - non-gravitational orbits for standard g(r)
data weighting YES
number of residuals 9988
RMS [arcseconds] 0.39
orbit quality class 1a+
orbital elements (heliocentric ecliptic J2000)
Epoch 2015 12 04
perihelion date 2015 11 15.72142833 ± 0.00000988
perihelion distance [au] 0.82296785 ± 0.00000011
eccentricity 1.00028494 ± 0.00000049
argument of perihelion [°] 340.358327 ± 0.000016
ascending node [°] 186.144638 ± 0.000010
inclination [°] 148.878343 ± 0.000002
reciprocal semi-major axis [10-6 au-1] -346.24 ± 0.59
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] 0.78587 ± 0.00821
A2 [10-8au/day2] 0.017296 ± 0.00231
A3 [10-8au/day2] -0.002498 ± 0.001913
m -2.15
n 5.093
k -4.6142
r0 [au] 2.808
α 0.1113