C/1925 F1

Solar System
Dynamics &
Planetology
Group

C/1925 F1 Shajn–Comas Sola

General description

Comet C/1925 F1 was discovered on 22 March 1925, more then five months before perihelion passage, and was last seen on 4 March 1927 [Kronk, Cometography: Volume 3].

This comet made its closest approach to the Earth on 25 March 1925 (3.42 au), that is about three days after its discovery; it has second close approach to the Earth on 27 January 1926 (3.48 au).

Solution given below is based on data span over 1.95 yr in a range of heliocentric distances from 4.41 au through perihelion (4.18 au) to 6.07 au.

Comet suffered slight planetary perturbations during its passage through the planetary system that led to a slightly more tight future orbit in comparison to original one.

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 C1925F1A6-001

Comet C/1925 F1 Shajn–Comas Sola

number of observations	265
number of residuals	463
data interval	1925 Mar. 22 — 1927 Mar. 4
rms [arcsec]	2.75
orbit quality class	1b

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT)	19250907.0	= JD 2424400.5
time of perihelion passage (TT)	19250906.941564	± 0.003963
perihelion distance	4.18078079	± 0.00002336
eccentricity	1.00243417	± 0.00003527
argument of perihelion [deg]	205.759883	± 0.000570
longitude of the ascending node [deg]	358.539358	± 0.000095
inclination [deg]	146.713185	± 0.000143
inverse semimajor axis [10^-6 au^-1]	-582.23	± 8.43

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/1925 F1. 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)	16210722
time of perihelion passage (TT)	19250906.261864	± 0.003958
perihelion distance	4.17819249	± 0.00002340
eccentricity	0.99985439	± 0.00003482
argument of perihelion [deg]	205.622401	± 0.000574
longitude of the ascending node [deg]	358.368841	± 0.000093
inclination [deg]	146.741752	± 0.000145
inverse semimajor axis [10^-6 au^-1]	34.85	± 8.33

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/1925 F1. 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)	22301127
time of perihelion passage (TT)	19250905.761751	± 0.004023
perihelion distance	4.18479767	± 0.00002337
eccentricity	0.99946443	± 0.00003487
argument of perihelion [deg]	205.679732	± 0.000573
longitude of the ascending node [deg]	358.527886	± 0.000097
inclination [deg]	146.715638	± 0.000144
inverse semimajor axis [10^-6 au^-1]	127.98	± 8.33