C/2004 X2 (LINEAR)

Metadata

Parameter Value
Designation C/2004 X2 (LINEAR)
Type C
Perihelion (tp_cal, UTC) 2004-08-24T08:00:06.079680Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:30:45Z
Obs used 252
NEO -
M1 12.900
K1 4.500
PC -
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 2005-01-15.0000000
e 0.99737720
q (au) 3.793087
a (au) 1446.194953
i (deg) 72.117890
Ω (om, deg) 307.341187
ω (w, deg) 162.215319
M (ma, deg) 0.002575

Magnitude

C/2004 X2 (LINEAR) · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (15.808 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 15.808
n 2.000
gf 1.000
gb -0.783
k 0.800
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

Ephemeris

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-09-20 00:00 19:52:18.51 -72:02:44.3 HIP 97644 18.03
2026-09-20 12:00 19:52:14.30 -72:02:13.7 HIP 97644 17.43
2026-09-21 00:00 19:52:10.17 -72:01:42.9 HIP 97644 16.83
2026-09-21 12:00 19:52:06.11 -72:01:11.9 HIP 97644 16.24
2026-09-22 00:00 19:52:02.12 -72:00:40.8 HIP 97644 15.64
2026-09-22 12:00 19:51:58.21 -72:00:09.5 HIP 97644 15.04
2026-09-23 00:00 19:51:54.38 -71:59:38.0 HIP 97644 14.44
2026-09-23 12:00 19:51:50.62 -71:59:06.4 HIP 97644 13.84
2026-09-24 00:00 19:51:46.94 -71:58:34.6 HIP 97644 13.24
2026-09-24 12:00 19:51:43.34 -71:58:02.7 HIP 97644 12.65
2026-09-25 00:00 19:51:39.81 -71:57:30.6 HIP 97644 12.05
2026-09-25 12:00 19:51:36.36 -71:56:58.4 HIP 97644 11.45
2026-09-26 00:00 19:51:32.98 -71:56:26.0 HIP 97644 10.85
2026-09-26 12:00 19:51:29.68 -71:55:53.4 HIP 97644 10.26
2026-09-27 00:00 19:51:26.46 -71:55:20.8 HIP 97644 9.66
2026-09-27 12:00 19:51:23.32 -71:54:47.9 HIP 97644 9.06
2026-09-28 00:00 19:51:20.25 -71:54:15.0 HIP 97644 8.46
2026-09-28 12:00 19:51:17.26 -71:53:41.9 HIP 97644 7.87
2026-09-29 00:00 19:51:14.35 -71:53:08.6 HIP 97644 7.27
2026-09-29 12:00 19:51:11.52 -71:52:35.3 HIP 97644 6.67
2026-09-30 00:00 19:51:08.76 -71:52:01.8 HIP 97644 6.07
2026-09-30 12:00 19:51:06.08 -71:51:28.1 HIP 97644 5.47
2026-10-01 00:00 19:51:03.48 -71:50:54.4 HIP 97644 4.88
2026-10-01 12:00 19:51:00.96 -71:50:20.5 HIP 97644 4.28
2026-10-02 00:00 19:50:58.51 -71:49:46.5 HIP 97644 3.68
2026-10-02 12:00 19:50:56.15 -71:49:12.4 HIP 97644 3.08
2026-10-03 00:00 19:50:53.86 -71:48:38.1 HIP 97644 2.48
2026-10-03 12:00 19:50:51.65 -71:48:03.8 HIP 97644 1.89
2026-10-04 00:00 19:50:49.52 -71:47:29.3 HIP 97644 1.29
2026-10-04 12:00 19:50:47.47 -71:46:54.7 HIP 97644 0.70
2026-10-05 00:00 19:50:45.50 -71:46:20.1 HIP 97644 0.16
2026-10-05 12:00 19:50:43.61 -71:45:45.3 HIP 97644 0.53
2026-10-06 00:00 19:50:41.79 -71:45:10.4 HIP 97644 1.12
2026-10-06 12:00 19:50:40.06 -71:44:35.4 HIP 97644 1.72
2026-10-07 00:00 19:50:38.40 -71:44:00.3 HIP 97644 2.32
2026-10-07 12:00 19:50:36.83 -71:43:25.1 HIP 97644 2.91
2026-10-08 00:00 19:50:35.33 -71:42:49.9 HIP 97644 3.51
2026-10-08 12:00 19:50:33.91 -71:42:14.5 HIP 97644 4.11
2026-10-09 00:00 19:50:32.57 -71:41:39.1 HIP 97644 4.71
2026-10-09 12:00 19:50:31.32 -71:41:03.5 HIP 97644 5.31
2026-10-10 00:00 19:50:30.14 -71:40:27.9 HIP 97644 5.91
2026-10-10 12:00 19:50:29.04 -71:39:52.2 HIP 97644 6.52
2026-10-11 00:00 19:50:28.02 -71:39:16.4 HIP 97644 7.12