C/2009 P2 Boattini
more info
C/2009 P2 was discovered by Andrea Boattini on 15 August 2009 during the Catalina Sky Survey with the 0.68 m Schmidt; its cometary apperance was next confirmed by several amateur observers. Later, positional observations of C/2009 P2 were linked with data of two asteroidal objects: 2008 TQ137 and 2008 VP28 taken between 1–9 October 2008 [MPEC 2009-R29, 2009 Sept. 9].
This comet made its closest approaches to the Earth on 21 September 2009 (5.649 au, 4.7 months before perihelion passage) and 17 August 2010 (5.704 au, 6.2 months after perihelion), see figure.
Solution given here is based on data spanning over 2.8 yr in a range of heliocentric distances: 7.33 au – 6.544 au (perihelion) – 7.53 au.
This Oort spike comet suffers tiny planetary perturbations during its passage through the planetary system.
See also Królikowska 2014 and Królikowska and Dybczyński 2017.

solution description
number of observations 503
data interval 2008 10 01 – 2011 07 29
data type perihelion within the observation arc (FULL)
data arc selection entire data set (STD)
range of heliocentric distances 7.33 au – 6.54 au (perihelion) – 7.53 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 982
RMS [arcseconds] 0.51
orbit quality class 1a
orbital elements (heliocentric ecliptic J2000)
Epoch 2010 02 13
perihelion date 2010 02 10.86308500 ± 0.00127800
perihelion distance [au] 6.54387710 ± 0.00000891
eccentricity 1.00183747 ± 0.00000903
argument of perihelion [°] 76.088005 ± 0.000124
ascending node [°] 60.392108 ± 0.000066
inclination [°] 163.455157 ± 0.000011
recip semi-major axis [10-6 au-1] -280.79 ± 1.38
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