C/2003 WT42 (LINEAR)

Metadata

Parameter Value
Designation C/2003 WT42 (LINEAR)
Type C
Perihelion (tp_cal, UTC) 2006-04-10T18:20:21.065280Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:30:36Z
Obs used 2466
NEO -
M1 6.200
K1 8.500
PC 0.030
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 2006-04-09.0000000
e 1.00258438
q (au) 5.190924
a (au) -2008.572797
i (deg) 31.410588
Ω (om, deg) 48.453889
ω (w, deg) 92.466923
M (ma, deg) -0.000019

Magnitude

C/2003 WT42 (LINEAR) · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (-0.750 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 -0.750
n 6.000
gf 1.000
gb -1.000
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
2003-12-01 2006-04-02 -4.0705 +3.107
2006-04-17 2007-07-07 +16.4914 -11.805

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

Ephemeris

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-07-29 00:00 18:08:37.21 -47:00:00.0 HIP 88782 13.56
2026-07-29 12:00 18:08:33.75 -46:59:51.2 HIP 88782 12.96
2026-07-30 00:00 18:08:30.30 -46:59:42.3 HIP 88782 12.37
2026-07-30 12:00 18:08:26.88 -46:59:33.3 HIP 88782 11.79
2026-07-31 00:00 18:08:23.48 -46:59:24.1 HIP 88782 11.21
2026-07-31 12:00 18:08:20.11 -46:59:14.8 HIP 88782 10.63
2026-08-01 00:00 18:08:16.76 -46:59:05.3 HIP 88782 10.06
2026-08-01 12:00 18:08:13.44 -46:58:55.7 HIP 88782 9.49
2026-08-02 00:00 18:08:10.14 -46:58:45.9 HIP 88782 8.93
2026-08-02 12:00 18:08:06.87 -46:58:36.1 HIP 88782 8.37
2026-08-03 00:00 18:08:03.62 -46:58:26.1 HIP 88782 7.82
2026-08-03 12:00 18:08:00.40 -46:58:15.9 HIP 88782 7.28
2026-08-04 00:00 18:07:57.21 -46:58:05.7 HIP 88782 6.74
2026-08-04 12:00 18:07:54.04 -46:57:55.3 HIP 88782 6.21
2026-08-05 00:00 18:07:50.90 -46:57:44.8 HIP 88782 5.69
2026-08-05 12:00 18:07:47.78 -46:57:34.1 HIP 88782 5.19
2026-08-06 00:00 18:07:44.69 -46:57:23.3 HIP 88782 4.69
2026-08-06 12:00 18:07:41.63 -46:57:12.4 HIP 88782 4.21
2026-08-07 00:00 18:07:38.60 -46:57:01.4 HIP 88782 3.76
2026-08-07 12:00 18:07:35.60 -46:56:50.3 HIP 88782 3.33
2026-08-08 00:00 18:07:32.62 -46:56:39.0 HIP 88782 2.95
2026-08-08 12:00 18:07:29.67 -46:56:27.6 HIP 88782 2.61
2026-08-09 00:00 18:07:26.75 -46:56:16.1 HIP 88782 2.36
2026-08-09 12:00 18:07:23.87 -46:56:04.4 HIP 88782 2.20
2026-08-10 00:00 18:07:21.01 -46:55:52.7 HIP 88782 2.16
2026-08-10 12:00 18:07:18.17 -46:55:40.8 HIP 88782 2.24
2026-08-11 00:00 18:07:15.37 -46:55:28.8 HIP 88782 2.43
2026-08-11 12:00 18:07:12.60 -46:55:16.7 HIP 88782 2.70
2026-08-12 00:00 18:07:09.86 -46:55:04.5 HIP 88782 3.03
2026-08-12 12:00 18:07:07.15 -46:54:52.2 HIP 88782 3.40
2026-08-13 00:00 18:07:04.48 -46:54:39.7 HIP 88782 3.79
2026-08-13 12:00 18:07:01.83 -46:54:27.2 HIP 88782 4.20
2026-08-14 00:00 18:06:59.21 -46:54:14.5 HIP 88782 4.63
2026-08-14 12:00 18:06:56.63 -46:54:01.8 HIP 88782 5.06
2026-08-15 00:00 18:06:54.08 -46:53:48.9 HIP 88782 5.49
2026-08-15 12:00 18:06:51.56 -46:53:35.9 HIP 88782 5.93
2026-08-16 00:00 18:06:49.07 -46:53:22.8 HIP 88782 6.37
2026-08-16 12:00 18:06:46.61 -46:53:09.6 HIP 88782 6.81
2026-08-17 00:00 18:06:44.19 -46:52:56.4 HIP 88782 7.25
2026-08-17 12:00 18:06:41.80 -46:52:43.0 HIP 88782 7.69
2026-08-18 00:00 18:06:39.44 -46:52:29.5 HIP 88782 8.12
2026-08-18 12:00 18:06:37.11 -46:52:15.9 HIP 88782 8.55
2026-08-19 00:00 18:06:34.82 -46:52:02.3 HIP 88782 8.98