C/1954 Y1 Haro-Chavira

Solar System
Dynamics &
Planetology
Group

General description

Comet C/1954 Y1 was discovered on 18 December 1954, about one year before perihelion passage, and was last seen on 15 May 1958 [Kronk, Cometography: Volume 4].

The comet made its closest approach to Earth on 9 December 1955 (3.51 au), almost seven weeks before perihelion passage.

Solution given below is based on data span over 3.3 yrs in the range of heliocentric distances: 5.16 au – 4.08 au (perihelion) – 7.79 au.

Figure caption: 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.

SSDP Cometary Note C1954Y1A5-001

Comet C/1954 Y1 - Haro-Chavira

number of observations	97
number of residuals	181
data interval	1955 Jan. 13 — 1958 May 15
rms [arcsec]	0.98
orbit quality class	1a

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT)	19560108.0	= JD 2435480.5
time of perihelion passage (TT)	19560126.665126	± 0.000797
perihelion distance	4.07687153	± 0.00000441
eccentricity	1.00466934	± 0.00001072
argument of perihelion [deg]	57.297597	± 0.000103
longitude of the ascending node [deg]	72.872267	± 0.000037
inclination [deg]	79.599992	± 0.000048
inverse semimajor axis [10^-6 au^-1]	-1145.32	± 2.63

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

Figure caption: Six 2D-projections of the 6D space of original swarm (5001 VCs) of C/1954 Y1. Each density map is given in logarithmic scale presented on the right in the individual panel.
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Original orbital elements (barycentric; at 250 au from the Sun)

Epoch (TT)	16520210
time of perihelion passage (TT)	19560127.139328	± 0.000816
perihelion distance	4.07097096	± 0.00000452
eccentricity	0.99984448	± 0.00001082
argument of perihelion [deg]	57.447014	± 0.000104
longitude of the ascending node [deg]	72.821449	± 0.000037
inclination [deg]	79.681137	± 0.000048
inverse semimajor axis [10^-6 au^-1]	38.20	± 2.66

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.

Figure caption: Six 2D-projections of the 6D space of future swarm (5001 VCs) of C/1954 Y1. Each density map is given in logarithmic scale presented on the right in the individual panel.
The same figure in the new window

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

Epoch (TT)	22561220
time of perihelion passage (TT)	19560127.267825	± 0.000808
perihelion distance	4.07269187	± 0.00000450
eccentricity	1.00093116	± 0.00001082
argument of perihelion [deg]	57.209560	± 0.000105
longitude of the ascending node [deg]	72.861102	± 0.000037
inclination [deg]	79.680979	± 0.000048
inverse semimajor axis [10^-6 au^-1]	-228.63	± 2.66