C/2017 U7
more info
Comet C/2017 U7 was discovered on 29 October 2017 with Pan-STARRS 1 telescope (Haleakala), that is almost 2 years before its perihelion passage. Several prediscovery images of this comet were found: taken by the same survey from 18 August and 13 September 2017. This comet was observed until 3 August 2022 (as on September 2023).

Comet had its closest approach to the Earth on 1 August 2019 (5.493 au), less than 1.5 months before its perihelion passage.

The preferred solution given here is based on data spanning over 4.96 yr in a range of heliocentric distances from 8.14 au – 6.42 au (perihelion) – 9.41 au.

This near-parabolic comet (original semimajor axis around 9,000 au) suffers small planetary perturbations during its passage through the planetary system that likely lead to escape the comet from the planetary zone on a hyperbolic orbit (see future barycentric orbits).
solution description
number of observations 920
data interval 2017 08 18 – 2022 08 03
data type perihelion within the observation arc (FULL)
data arc selection entire data set (STD)
range of heliocentric distances 8.14 au – 6.42 au (perihelion) – 9.41 au
type of model of motion NC - non-gravitational orbits for symmetric CO-g(r)-like function
data weighting YES
number of residuals 1781
RMS [arcseconds] 0.34
orbit quality class 1a+
orbital elements (heliocentric ecliptic J2000)
Epoch 2019 08 25
perihelion date 2019 09 11.26912891 ± 0.00103215
perihelion distance [au] 6.41727338 ± 0.00000332
eccentricity 1.00078200 ± 0.00000291
argument of perihelion [°] 326.031150 ± 0.000090
ascending node [°] 276.232278 ± 0.000007
inclination [°] 142.635329 ± 0.000005
reciprocal semi-major axis [10-6 au-1] -121.86 ± 0.45
non-gravitational parameters
A1 [10-8au/day2] 1.2919 ± 0.1311
A2 [10-8au/day2] 1.9642 ± 0.1856
A3 [10-8au/day2] 0.18162 ± 0.03028
m -2.00
n 3.000
k -2.6000
r0 [au] 10.000
α 0.0100