C/1999 H3 LINEAR
more info
C/1999 H3 was discovered as an apparently asteroidal object by LINEAR on 22 April 1999 (about four months before perihelion passage). Next day was reported as cometary object by observers from Klet and Ondrejov [IAUC 7151, 1999 April 23].
This comet made its closest approach to the Earth on 6 March 2000 (3.185 au), about 6.5 months after perihelion.
Solutions given here are based on data spanning over 2.9 yr in a range of heliocentric distances: 3.66 au –3.501 au (perihelion)–8.48 au.
This comet suffers small planetary perturbations during its passage through the planetary system; however, these perturbations lead to escape of the comet from the solar system on hiperbolic orbit (see future barycentric orbit).
See also Królikowska 2014 and Królikowska and Dybczyński 2017.

solution description
number of observations 877
data interval 1999 04 22 – 2002 03 20
data type significantly more measurements after perihelion (POST+)
data arc selection entire data set (STD)
range of heliocentric distances 3.66 au – 3.50 au (perihelion) – 8.48 au
type of model of motion NS - non-gravitational orbits for standard g(r)
data weighting YES
number of residuals 1722
RMS [arcseconds] 0.51
orbit quality class 1a
orbital elements (heliocentric ecliptic J2000)
Epoch 1999 08 10
perihelion date 1999 08 18.24196100 ± 0.00087000
perihelion distance [au] 3.50080910 ± 0.00000249
eccentricity 1.00269373 ± 0.00000619
argument of perihelion [°] 101.912685 ± 0.000199
ascending node [°] 332.723748 ± 0.000035
inclination [°] 115.840364 ± 0.000012
recip semi-major axis [10-6 au-1] -769.46 ± 1.77
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\day-2] 4112 ± 193
A2 [10-8au\day-2] 3007 ± 228
A3 [10-8au\day-2] -509 ± 72
m -2.15
n 5.093
k -4.6142
r0 [au] 2.808
α 0.1113