C/2014 A4 SONEAR
more info
Comet C/2014 A4 was discovered on 12 January 2014 with Southern Observatory for Near Earth Research (Oliveira, Brazil), that is about 8 months before its perihelion passage. This comet was observed during five oppositions until 17 September 2017.
Comet had its closest approach to the Earth on 19 October 2015 (3.203 au), about 1.5 month after its perihelion passage.
Solutions given here are based on data spanning over 3.68 yr in a range of heliocentric distances: 6.40 au – 4.180 au (perihelion) – 7.21 au.
This comet suffers small planetary perturbations during its passage through the planetary system; these perturbations lead to a more tight future orbit (see future barycentric orbits).

solution description
number of observations 2825
data interval 2014 01 12 – 2017 09 17
data type perihelion within the observation arc (FULL)
data arc selection entire data set (STD)
range of heliocentric distances 6.4 au – 4.18 au (perihelion) – 7.21 au
type of model of motion NC - non-gravitational orbits for symmetric CO-g(r)-like function
data weighting YES
number of residuals 5557
RMS [arcseconds] 0.41
orbit quality class 1a+
orbital elements (heliocentric ecliptic J2000)
Epoch 2015 09 15
perihelion date 2015 09 05.86582480 ± 0.00022580
perihelion distance [au] 4.18021025 ± 0.00000096
eccentricity 1.00084664 ± 0.00000148
argument of perihelion [°] 356.788675 ± 0.000037
ascending node [°] 29.727181 ± 0.000003
inclination [°] 121.358876 ± 0.000004
reciprocal semi-major axis [10-6 au-1] -202.53 ± 0.35
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.
non-gravitational parameters
A1 [10-8au/day2] -1.2318 ± 0.0343
A2 [10-8au/day2] -0.29998 ± 0.05532
A3 [10-8au/day2] -0.00721 ± 0.01157
m -2.00
n 3.000
k -2.6000
r0 [au] 10.000
α 0.0100