Metadata

Parameter	Value
Designation	C/1942 X1 (Whipple-Fedtke-Tevzadze)
Type	C
Perihelion (tp_cal, UTC)	1943-02-06T17:18:23.040000Z
Orbit solution date (soln_date, UTC)	-
Obs used	166
NEO	-
M1	-
K1	-
PC	-

Osculating Elements

Parameter	Value
Epoch (epoch_cal, TDB)	1943-02-05.0000000
e	0.99219600
q (au)	1.353647
a (au)	173.455536
i (deg)	19.712700
Ω (om, deg)	100.799000
ω (w, deg)	39.843200
M (ma, deg)	-0.000743

Magnitude

Scatter + Global Linear

$$ M_a = (3.857 + 3.863\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter	Value
H0	3.857
n	3.863
gf	1.000
gb	-0.500
k	1.000
δ90	10.000

Parameter	Symbol	Range	Description
Absolute magnitude at 1 AU from Sun and Earth	H0	-5 to 20	Intrinsic brightness of the comet
Photometric slope parameter	n	2 to 6	Rate of brightness change with heliocentric distance
Forward scattering asymmetry factor	gf	0.8 to 1	Degree of forward scattering
Backward scattering asymmetry factor	gb	-1 to -0.5	Degree of backward scattering
Partitioning coefficient	k	0.8 to 1	Ratio between forward/backward scattering contributions
Dust-to-gas brightness ratio	δ90	1 to 10	Relative contribution of dust scattering to gas emission

Reference: EPSC-DPS2025-160

Residuals (Piecewise)

$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$

Start (UTC)	End (UTC)	a	b
1942-12-15	1943-02-06	+38.1961	-4.915
1943-02-06	1943-04-13	+2.8278	-0.764
1943-04-13	1943-06-05	-2.7997	+0.823

log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)

Ephemeris

Date/Time (UTC)	RA (J2000)	Dec (J2000)	Nearest HIP	Dist from HIP (arcmin)
2026-06-01 00:00	20:54:35.52	-27:07:36.6	HIP 103182	30.29
2026-06-01 12:00	20:54:34.93	-27:07:41.5	HIP 103182	30.35
2026-06-02 00:00	20:54:34.32	-27:07:46.5	HIP 103182	30.42
2026-06-02 12:00	20:54:33.71	-27:07:51.5	HIP 103182	30.49
2026-06-03 00:00	20:54:33.08	-27:07:56.6	HIP 103182	30.56
2026-06-03 12:00	20:54:32.45	-27:08:01.6	HIP 103182	30.63
2026-06-04 00:00	20:54:31.81	-27:08:06.7	HIP 103182	30.70
2026-06-04 12:00	20:54:31.16	-27:08:11.8	HIP 103182	30.77
2026-06-05 00:00	20:54:30.49	-27:08:16.9	HIP 103182	30.84
2026-06-05 12:00	20:54:29.82	-27:08:22.1	HIP 103182	30.91
2026-06-06 00:00	20:54:29.14	-27:08:27.2	HIP 103182	30.99
2026-06-06 12:00	20:54:28.45	-27:08:32.4	HIP 103182	31.06
2026-06-07 00:00	20:54:27.75	-27:08:37.6	HIP 103182	31.14
2026-06-07 12:00	20:54:27.05	-27:08:42.8	HIP 103182	31.21
2026-06-08 00:00	20:54:26.33	-27:08:48.1	HIP 103182	31.29
2026-06-08 12:00	20:54:25.61	-27:08:53.3	HIP 103182	31.37
2026-06-09 00:00	20:54:24.87	-27:08:58.6	HIP 103182	31.45
2026-06-09 12:00	20:54:24.13	-27:09:03.9	HIP 103182	31.53
2026-06-10 00:00	20:54:23.38	-27:09:09.2	HIP 103182	31.61
2026-06-10 12:00	20:54:22.62	-27:09:14.6	HIP 103182	31.70
2026-06-11 00:00	20:54:21.85	-27:09:19.9	HIP 103182	31.78
2026-06-11 12:00	20:54:21.07	-27:09:25.3	HIP 103182	31.87
2026-06-12 00:00	20:54:20.28	-27:09:30.7	HIP 103182	31.95
2026-06-12 12:00	20:54:19.49	-27:09:36.1	HIP 103182	32.04
2026-06-13 00:00	20:54:18.68	-27:09:41.5	HIP 103182	32.13
2026-06-13 12:00	20:54:17.87	-27:09:46.9	HIP 103182	32.22
2026-06-14 00:00	20:54:17.05	-27:09:52.4	HIP 103182	32.31
2026-06-14 12:00	20:54:16.22	-27:09:57.8	HIP 103182	32.41
2026-06-15 00:00	20:54:15.38	-27:10:03.3	HIP 103182	32.50
2026-06-15 12:00	20:54:14.54	-27:10:08.8	HIP 103182	32.60
2026-06-16 00:00	20:54:13.68	-27:10:14.3	HIP 103182	32.70
2026-06-16 12:00	20:54:12.82	-27:10:19.8	HIP 103182	32.80
2026-06-17 00:00	20:54:11.95	-27:10:25.3	HIP 103182	32.90
2026-06-17 12:00	20:54:11.07	-27:10:30.8	HIP 103182	33.00
2026-06-18 00:00	20:54:10.19	-27:10:36.4	HIP 103182	33.10
2026-06-18 12:00	20:54:09.30	-27:10:41.9	HIP 103182	33.20
2026-06-19 00:00	20:54:08.40	-27:10:47.5	HIP 103182	33.31
2026-06-19 12:00	20:54:07.49	-27:10:53.1	HIP 103182	33.42
2026-06-20 00:00	20:54:06.57	-27:10:58.7	HIP 103182	33.52
2026-06-20 12:00	20:54:05.65	-27:11:04.3	HIP 103182	33.63
2026-06-21 00:00	20:54:04.72	-27:11:09.9	HIP 103182	33.75
2026-06-21 12:00	20:54:03.78	-27:11:15.5	HIP 102954	33.56
2026-06-22 00:00	20:54:02.83	-27:11:21.1	HIP 102954	33.34