C/2007 U1 LINEAR
more info
Comet C/2007 U1 was discovered on 19 October 2007 by LINEAR project, 9.5 months before its perihelion passage.
C/2007 U1 was observed 2.1 yr during three oppositions in a range of heliocentric distances: 4.28 au – 3.329 au (perihelion) – 5.36 au.
Comet had its closest approach to the Earth on 21 October 2008 (2.424 au, 2.5 months after perihelion).
This comet suffers small planetary perturbations during its passage through the planetary system that lead to a less tight orbit with semimajor axis larger than 10,000 au.
See also Królikowska and Dybczyński 2017.

solution description
number of observations 896
data interval 2007 10 19 – 2009 11 18
data type perihelion within the observation arc (FULL)
data arc selection entire data set (STD)
range of heliocentric distances 4.28 au – 3.33 au (perihelion) – 5.36 au
type of model of motion NS - non-gravitational orbits for standard g(r)
data weighting YES
number of residuals 1774
RMS [arcseconds] 0.41
orbit quality class 1a
orbital elements (heliocentric ecliptic J2000)
Epoch 2008 08 02
perihelion date 2008 08 07.05297755 ± 0.00031820
perihelion distance [au] 3.32916349 ± 0.00000195
eccentricity 1.00141625 ± 0.00000446
argument of perihelion [°] 0.928036 ± 0.000079
ascending node [°] 50.043066 ± 0.000020
inclination [°] 157.786884 ± 0.00001
recip semi-major axis [10-6 au-1] -425.41 ± 1.34
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
non-gravitational parameters
A1 [10-8au\day-2] 685 ± 45
A2 [10-8au\day-2] -222 ± 89
A3 [10-8au\day-2] -172 ± 18
m -2.15
n 5.093
k -4.6142
r0 [au] 2.808
α 0.1113