C/2015 O1 PANSTARRS
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Comet C/2015 O1 was discovered on 19 July 2015 with Pan-STARRS 1 telescope (Haleakala), that is about  months after its perihelion passage.

Some prediscovery images of this comet were found: taken on 15 and 17 of June 2015 by Space Surveillance Telescope (Atom Site).

Solutions given here are based on data spanning over 4.76 yr in a range of heliocentric distances: 8.65 au – 3.730 au (perihelion) – 7.28 au.

NG orbits using full data-arc as well as independently using pre-perihelion and post-perihelion data are determinable.

See also Królikowska and Dones 2023.
solution description
number of observations 1903
data interval 2015 06 11 – 2018 02 18
data arc selection data generally limited to pre-perihelion (PRE)
range of heliocentric distances 8.65 au – 3.73au
type of model of motion NC - non-gravitational orbits for symmetric CO-g(r)-like function
data weighting YES
number of residuals 3783
RMS [arcseconds] 0.33
orbit quality class 1a
orbital elements (heliocentric ecliptic J2000)
Epoch 2018 03 23
perihelion date 2018 02 19.03141784 ± 0.00153809
perihelion distance [au] 3.72963321 ± 0.00000488
eccentricity 0.99998700 ± 0.00000396
argument of perihelion [°] 89.595260 ± 0.000321
ascending node [°] 299.857101 ± 0.000035
inclination [°] 127.210933 ± 0.000012
reciprocal semi-major axis [10-6 au-1] 3.49 ± 1.06
Upper panel: 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.
Middle panel(s): O-C diagram for a given solution (sometimes in comparison to another solution available in CODE), where residuals in right ascension are shown using magenta dots and in declination by blue open circles.
Lowest panel: Relative weights for a given data set(s).
non-gravitational parameters
A1 [10-8au/day2] 3.8198 ± 0.1449
A2 [10-8au/day2] -0.03321 ± 0.11834
A3 [10-8au/day2] -0.11754 ± 0.03271
m -2.00
n 3.000
k -2.6000
r0 [au] 10.000
α 0.0100