C/2016 X1 Lemmon
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Comet C/2016 X1 was discovered on 8 December 2016 with Mount Lemmon survey, that is about 2.3 yr before its perihelion passage. Some prediscovery images of this comet were found: taken on 26 November 2016 by Pan-STARRS 1 telescope (Haleakala). This comet was observed until the end of 2019 and is still observable.
Comet had its closest approach to the Earth on 13 January 2019 (6.652 au), about 3.5 months before its perihelion passage.
Solution given here is based on data spanning over 1.39 yr in a range of heliocentric distances from 9.30 au to 8.20 au (18 April 2018).
This is comet with original semimajor likely shorter than 5,000 au.

solution description
number of observations 105
data interval 2016 11 26 – 2018 04 18
data type observed only before perihelion (PRE)
data arc selection entire data set (STD)
range of heliocentric distances 9.3 au – 8.2au
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 192
RMS [arcseconds] 0.42
orbit quality class 1a
next orbit statistics, both Galactic and stellar perturbations were taken into account
no. of returning VCs in the swarm 5001 *
no. of escaping VCs in the swarm 0
no. of hyperbolas among escaping VCs in the swarm 0
next reciprocal semi-major axis [10-6 au-1] 491.74 – 496.77 – 502.15
next perihelion distance [au] 7.58096 – 7.58108 – 7.5812
next aphelion distance [103 au] 3.98 – 4.02 – 4.06
time interval to next perihelion [Myr] 0.0885 – 0.09 – 0.0913
percentage of VCs with qnext < 10100
next orbit statistics, here only the Galactic tide has been included
no. of returning VCs in the swarm 5001 *
no. of escaping VCs in the swarm 0
no. of hyperbolas among escaping VCs in the swarm 0
next reciprocal semi-major axis [10-6 au-1] 491.74 – 496.77 – 502.14
next perihelion distance [au] 7.57274 – 7.57293 – 7.57312
next aphelion distance [103 au] 3.98 – 4.02 – 4.06
time interval to next perihelion [Myr] 0.0885 – 0.09 – 0.0914
percentage of VCs with qnext < 10100