C/2008 P1 Garradd
more info
C/2008 P1 was discovered by Gordon J. Garradd on 13 August 2008 on images taken with the 0.5-m Uppsala Schmidt telescope at Siding Spring; its cometary apperance was next confirmed by C. Jacques and E. Pimentel (Belo Horizonte, Minas Gerais, Brazil, 0.30-m reflector) [IAUC 8965, 2008 August 15].
This comet made its closest approach to the Earth on 22 September 2009 (3.028 au), two months after perihelion passage.
Solution given here is based on data spanning over 2.5 yr in a range of heliocentric distances: 4.88 au – 3.896 au (perihelion) – 6.08 au.
This comet suffers small planetary perturbations during its passage through the planetary system that lead to a more tight future orbit (see future barycentric orbit).
See also Królikowska 2014 and Królikowska and Dybczyński 2017.

solution description
number of observations 1373
data interval 2008 08 13 – 2011 02 04
data type perihelion within the observation arc (FULL)
data arc selection entire data set (STD)
range of heliocentric distances 4.88 au – 3.90 au (perihelion) – 6.08 au
detectability of NG effects in the comet's motion NG effects not determinable
type of model of motion GR - gravitational orbit
data weighting YES
number of residuals 415
RMS [arcseconds] 0.61
orbit quality class 1a+
orbital elements (heliocentric ecliptic J2000)
Epoch 2009 07 28
perihelion date 2009 07 22.93590500 ± 0.00024300
perihelion distance [au] 3.89610720 ± 0.00000108
eccentricity 1.00176244 ± 0.00000214
argument of perihelion [°] 11.862585 ± 0.000040
ascending node [°] 357.676590 ± 0.000005
inclination [°] 64.308943 ± 0.000009
recip semi-major axis [10-6 au-1] -452.36 ± 0.55
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