C/1948 T1

Solar System
Dynamics &
Planetology
Group

C/1948 T1 Wirtanen

General description

Comet C/1948 T1 was discovered on 7 October 1948, about 13 months after perihelion passage and was last seen on 11 September 1950 [Kronk, Cometography: Volume 4].

This comet made its closest approach to Earth on 26 October 1947 (2.44 au), that is one month after perihelion passage and almost one year before its discovery.

Solution given below is based on data span over 1.86 yr on postperihelion leg of orbit in a range of heliocentric distances from 4.89 au to 9.38 au.

Comet suffered small planetary perturbations during its passage through the planetary system that caused a bit tighter future orbit (see original and future barycentric orbits below).

More details in Królikowska et al. 2014, Królikowska and Dybczyński 2017

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 C1948T1A1-001

Comet C/1948 T1 Wirtanen

number of observations	26
number of residuals	52
data interval	1948 Oct. 7 — 1950 Aug. 17
rms [arcsec]	0.94
orbit quality class	1b

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT)	19470912.0	= JD 2432440.5
time of perihelion passage (TT)	19470904.429515	± 0.010323
perihelion distance	3.26110877	± 0.00011350
eccentricity	1.00227683	± 0.00003289
argument of perihelion [deg]	73.464822	± 0.001866
longitude of the ascending node [deg]	122.120668	± 0.000217
inclination [deg]	155.077948	± 0.000265
inverse semimajor axis [10^-6 au^-1]	-698.18	± 10.07

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/1948 T1. Each density map is given in logarithmic scale presented on the right in the individual panel.
The same figure in the new window

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

Epoch (TT)	16450206
time of perihelion passage (TT)	19470903.743055	± 0.010324
perihelion distance	3.26052435	± 0.00011079
eccentricity	0.99988853	± 0.00003277
argument of perihelion [deg]	73.395315	± 0.001840
longitude of the ascending node [deg]	121.990438	± 0.000217
inclination [deg]	155.123775	± 0.000260
inverse semimajor axis [10^-6 au^-1]	34.19	± 10.05

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/1948 T1. 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)	22520624
time of perihelion passage (TT)	19470903.674841	± 0.010358
perihelion distance	3.27021985	± 0.00011087
eccentricity	0.99926416	± 0.00003285
argument of perihelion [deg]	73.548717	± 0.001821
longitude of the ascending node [deg]	122.147554	± 0.000214
inclination [deg]	155.105084	± 0.000259
inverse semimajor axis [10^-6 au^-1]	225.01	± 10.05