C/2010 X1 Elenin
more info
Comet C/2010 X1 was discovered on 10 December 2010 by Leonid Elenin (Lyubertsy, Russia); that is about 9 months before its perihelion passage. This comet was observed until 1 September 2011; however it started to disintegrate in August.
The deepest approach to the Earth would be on 16 October 2011 (0.233 au), about a month after its perihelion passage.
The solution based on observations taken to the end of July/June/May exhibits some trends in O-C time variation. Therefore, the preferred solution given here is based on data taken before 1 May and spanning over 0.394 yr in a range of heliocentric distances from 4.22 auto 2.47 au.
This was an Oort spike comet.

See also Królikowska and Dybczyński 2013, Sekanina 2019, and Królikowska 2020.

solution description
number of observations 1734
data interval 2010 12 10 – 2011 04 30
data arc selection data generally limited to pre-perihelion (PRE)
range of heliocentric distances 4.22 au – 2.47au
detectability of NG effects in the comet's motion comet lost close to perihelion or split comet
type of model of motion GR - gravitational orbit
data weighting YES
number of residuals 4135
RMS [arcseconds] 0.46
orbit quality class 1b
orbital elements (heliocentric ecliptic J2000)
Epoch 2011 08 27
perihelion date 2011 09 10.72230767 ± 0.00027480
perihelion distance [au] 0.48245876 ± 0.00000223
eccentricity 1.00002960 ± 0.00000194
argument of perihelion [°] 343.807568 ± 0.000592
ascending node [°] 323.224967 ± 0.000597
inclination [°] 1.839147 ± 0.000032
recip semi-major axis [10-6 au-1] -61.34 ± 4.01
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