C/2003 T4 (LINEAR)

Metadata

Parameter Value
Designation C/2003 T4 (LINEAR)
Type C
Perihelion (tp_cal, UTC) 2005-04-03T15:45:28.166400Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:30:34Z
Obs used 955
NEO -
M1 9.200
K1 6.750
PC -
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 2004-10-20.0000000
e 1.00047448
q (au) 0.849741
a (au) -1790.885861
i (deg) 86.761193
Ω (om, deg) 93.902875
ω (w, deg) 181.679273
M (ma, deg) -0.002154

Magnitude

C/2003 T4 (LINEAR) · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (7.953 + 4.136\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 7.953
n 4.136
gf 0.800
gb -1.000
k 0.988
δ90 1.000
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
2003-10-13 2004-05-22 +1.4145 -1.791
2004-05-22 2004-09-06 +1.1723 -1.351
2004-09-06 2005-04-02 -1.5294 -0.289
2005-04-03 2005-05-04 +13.8649 +1.663
2005-05-04 2006-03-25 +0.8135 +1.141

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

Ephemeris

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-03-26 00:00 06:06:32.15 +08:41:19.6 HIP 29027 28.56
2026-03-26 12:00 06:06:32.31 +08:41:31.6 HIP 29027 28.72
2026-03-27 00:00 06:06:32.50 +08:41:43.6 HIP 29027 28.88
2026-03-27 12:00 06:06:32.71 +08:41:55.5 HIP 29027 29.03
2026-03-28 00:00 06:06:32.95 +08:42:07.5 HIP 29027 29.18
2026-03-28 12:00 06:06:33.20 +08:42:19.4 HIP 29002 29.05
2026-03-29 00:00 06:06:33.49 +08:42:31.3 HIP 29002 28.84
2026-03-29 12:00 06:06:33.80 +08:42:43.2 HIP 29002 28.63
2026-03-30 00:00 06:06:34.13 +08:42:55.1 HIP 29002 28.41
2026-03-30 12:00 06:06:34.48 +08:43:07.0 HIP 29002 28.20
2026-03-31 00:00 06:06:34.86 +08:43:18.8 HIP 29002 27.98
2026-03-31 12:00 06:06:35.27 +08:43:30.6 HIP 29002 27.77
2026-04-01 00:00 06:06:35.69 +08:43:42.4 HIP 29002 27.55
2026-04-01 12:00 06:06:36.15 +08:43:54.1 HIP 29002 27.33
2026-04-02 00:00 06:06:36.62 +08:44:05.9 HIP 29002 27.10
2026-04-02 12:00 06:06:37.12 +08:44:17.6 HIP 29002 26.88
2026-04-03 00:00 06:06:37.64 +08:44:29.2 HIP 29002 26.66
2026-04-03 12:00 06:06:38.19 +08:44:40.9 HIP 29002 26.43
2026-04-04 00:00 06:06:38.76 +08:44:52.5 HIP 29002 26.21
2026-04-04 12:00 06:06:39.35 +08:45:04.1 HIP 29002 25.98
2026-04-05 00:00 06:06:39.96 +08:45:15.7 HIP 29002 25.75
2026-04-05 12:00 06:06:40.60 +08:45:27.2 HIP 29002 25.52
2026-04-06 00:00 06:06:41.26 +08:45:38.7 HIP 29002 25.29
2026-04-06 12:00 06:06:41.95 +08:45:50.2 HIP 29002 25.06
2026-04-07 00:00 06:06:42.66 +08:46:01.6 HIP 29002 24.83
2026-04-07 12:00 06:06:43.39 +08:46:13.0 HIP 29002 24.60
2026-04-08 00:00 06:06:44.15 +08:46:24.4 HIP 29002 24.37
2026-04-08 12:00 06:06:44.92 +08:46:35.7 HIP 29002 24.14
2026-04-09 00:00 06:06:45.72 +08:46:47.1 HIP 29002 23.91
2026-04-09 12:00 06:06:46.55 +08:46:58.3 HIP 29002 23.68
2026-04-10 00:00 06:06:47.39 +08:47:09.6 HIP 29002 23.45
2026-04-10 12:00 06:06:48.26 +08:47:20.8 HIP 29002 23.21
2026-04-11 00:00 06:06:49.15 +08:47:31.9 HIP 29002 22.98
2026-04-11 12:00 06:06:50.07 +08:47:43.0 HIP 29002 22.76
2026-04-12 00:00 06:06:51.00 +08:47:54.1 HIP 29002 22.53
2026-04-12 12:00 06:06:51.96 +08:48:05.2 HIP 29002 22.30
2026-04-13 00:00 06:06:52.94 +08:48:16.2 HIP 29002 22.07
2026-04-13 12:00 06:06:53.94 +08:48:27.1 HIP 29002 21.85
2026-04-14 00:00 06:06:54.97 +08:48:38.0 HIP 29002 21.63
2026-04-14 12:00 06:06:56.01 +08:48:48.9 HIP 29002 21.41
2026-04-15 00:00 06:06:57.08 +08:48:59.7 HIP 29002 21.19
2026-04-15 12:00 06:06:58.17 +08:49:10.5 HIP 29002 20.98
2026-04-16 00:00 06:06:59.29 +08:49:21.3 HIP 29002 20.76