C/2008 FK75 old solution

Solar System
Dynamics &
Planetology
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C/2008 FK₇₅ Lemmon–Siding Spring

General description

C/2008 FK₇₅ was first discovered on 31 March 2008 in the course of the Mt.Lemmon Survey as an apparently asteroidal object. Next, independently was rediscovered by Siding Spring survey (again as apparently asteroidal) on 1 July 2008. Two days later, J. Young reported that images showed diffuse coma [IAUC 8958, 2008 July 7]; then other observers confirmed cometary appearance.

C/2008 FK₇₅ was discovered 1.7 yr before perihelion passage.

Comet had its closest approach to Earth on 16 June 2010 (4.057 au, 2.5 months before perihelion).

Solution given below is based on observations taken prior to 2013 June 5 and not include the non-gravitational effects. Non-gravitational solution and based on one-month longer observational arc is available here.

SSDP Cometary Note C2008FKA5-001 – older solution

Comet C/2008 FK₇₅ Lemmon–Siding Spring

number of observations	3704
number of residuals	7349
data interval	2008 Mar. 31 — 2013 Oct. 8
rms [arcsec]	0.52
orbit quality class	1a+

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT)	20101011.0	= JD 2455480.5
time of perihelion passage (TT)	20100929.255517	± 0.000092
perihelion distance	4.51085684	± 0.00000065
eccentricity	1.00253851	± 0.00000112
argument of perihelion [deg]	80.420270	± 0.000012
longitude of the ascending node [deg]	218.268510	± 0.000004
inclination [deg]	61.175997	± 0.000003
inverse semimajor axis [10^-6 au^-1]	-562.76	± 0.25

Note: Epoch is given in a format: yyyymmdd.d, time of perihelion passage in a format of yyyymmdd.dddddd.

Original orbital elements (barycentric; at 250 au from the Sun)

Epoch (TT)	17051229
time of perihelion passage (TT)	20100929.366575	± 0.000091
perihelion distance	4.50558286	± 0.00000070
eccentricity	0.99983540	± 0.00000113
argument of perihelion [deg]	80.520456	± 0.000012
longitude of the ascending node [deg]	218.228874	± 0.000004
inclination [deg]	61.190150	± 0.000003
inverse semimajor axis [10^-6 au^-1]	36.53	± 0.25

Note: Values of uncertainties of original/future orbital elements were derived using a swarm of 5001 osculating orbits of VCs (including the nominal osculating orbit given above) for original/future orbital evolution calclulations and then by fitting the distribution of a given orbital element of original/future swarm of VCs to Gaussian distribution.

Original barycentric positions and velocities of 5001 VCs at 250 au from the Sun are given here (data format), i.e. before entering the planetary zone.

Future orbital elements (barycentric; at 250 au from the Sun)

Epoch (TT)	23140220
time of perihelion passage (TT)	20100930.240221	± 0.000095
perihelion distance	4.50757790	± 0.00000057
eccentricity	1.00036763	± 0.00000112
argument of perihelion [deg]	80.408938	± 0.000012
longitude of the ascending node [deg]	218.247705	± 0.000004
inclination [deg]	61.190721	± 0.000003
inverse semimajor axis [10^-6 au^-1]	-81.56	± 0.25

Future barycentric positions and velocities of 5001 VCs at 250 au from the Sun are given here (data format), i.e. after leaving the planetary zone.