C/2002 O7 LINEAR
more info
Comet C/2002 O7 was discovered on 29 July 2002 with the Lincoln Laboratory Near-Earth Asteroid Research project, that is about a year and two months before its expected perihelion passage. Mattiazzo (2003) reported that C/2002 O7 was disrupted five days after perihelion, and a month later, the comet could no longer be found.
Comet had its closest approach to the Earth on 20 May 2003 (1.709 au), about 4 months before its perihelion passage.
Preffered solution given here is based on pre-perihelion data taken in perihelion distances larger than 2.44 au, that is spanning over 0.753 yr until 30 April 2003. Two NG solutions based on this shorter data-arc match the data equally, and both can be chosen as preferred solutions (dedicated to water ice ('pn') and CO ('p1') sublimation, respectively). Both these NG solutions give very different original 1/a.
See also Sekanina 2019 and Królikowska 2020.

solution description
number of observations 869
data interval 2002 07 29 – 2003 04 30
data arc selection data generally limited to pre-perihelion (PRE)
range of heliocentric distances 5.42 au – 2.44au
type of model of motion NS - non-gravitational orbits for standard g(r)
data weighting NO
number of residuals 1727
RMS [arcseconds] 0.76
orbit quality class 2a
orbital elements (heliocentric ecliptic J2000)
Epoch 2003 10 08
perihelion date 2003 09 22.08921764 ± 0.04205563
perihelion distance [au] 0.91034058 ± 0.00111382
eccentricity 1.01480506 ± 0.00905245
argument of perihelion [°] 251.012970 ± 0.270555
ascending node [°] 12.802588 ± 0.000059
inclination [°] 98.746246 ± 0.000067
recip semi-major axis [10-6 au-1] 16,263.21 ± 9,951.11
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] 192.82 ± 142.16
A2 [10-8au\day-2] 177.59 ± 43.55
A3 [10-8au\day-2] 0 (assumed)
m -2.15
n 5.093
k -4.6142
r0 [au] 2.808
α 0.1113