C/2018 U1 | CODEC

C/2018 U1 Lemmon

Comet C/2018 U1 was discovered on 27 October 2019, almost four years before its perihelion passage and is still observed (September 2023, 6.64 au from the Sun).

Currently, the solutions (GR and NG) given here are based on pre-perihelion data and span over 3.94 yr in a range of heliocentric distances: 9.33 au – 5.00 au (perihelion).

2018u1pa 2018u1pc

solution description
number of observations	2289
data interval	2019 02 08 – 2021 06 18
data arc selection	data generally limited to pre-perihelion (PRE)
range of heliocentric distances	9.33 au – 5au
type of model of motion	NC - non-gravitational orbits for symmetric CO-g(r)-like function
data weighting	YES
number of residuals	4524
RMS [arcseconds]	0.35
orbit quality class	1a+

previous 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
previous reciprocal semi-major axis [10^-6 au^-1]	69.55 – 70.75 – 71.91
previous perihelion distance [au]	4.768 – 4.783 – 4.796
previous aphelion distance [10³ au]	27.8 – 28.3 – 28.8
time interval to previous perihelion [Myr]	1.64 – 1.68 – 1.72
percentage of VCs with q_prev < 10	100

previous 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
previous reciprocal semi-major axis [10^-6 au^-1]	69.55 – 70.75 – 71.91
previous perihelion distance [au]	4.9096 – 4.9125 – 4.9152
previous aphelion distance [10³ au]	27.8 – 28.3 – 28.7
time interval to previous perihelion [Myr]	1.64 – 1.68 – 1.72
percentage of VCs with q_prev < 10	100