| 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
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 |
0.998 |
| 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) |
| 2026-03-26 00:00 |
20:22:28.58 |
-70:56:19.4 |
HIP 100466 |
15.44 |
| 2026-03-26 12:00 |
20:22:32.89 |
-70:56:43.8 |
HIP 100466 |
15.05 |
| 2026-03-27 00:00 |
20:22:37.12 |
-70:57:08.4 |
HIP 100466 |
14.66 |
| 2026-03-27 12:00 |
20:22:41.30 |
-70:57:33.2 |
HIP 100466 |
14.27 |
| 2026-03-28 00:00 |
20:22:45.41 |
-70:57:58.2 |
HIP 100466 |
13.89 |
| 2026-03-28 12:00 |
20:22:49.45 |
-70:58:23.3 |
HIP 100466 |
13.52 |
| 2026-03-29 00:00 |
20:22:53.43 |
-70:58:48.6 |
HIP 100466 |
13.16 |
| 2026-03-29 12:00 |
20:22:57.34 |
-70:59:14.1 |
HIP 100466 |
12.80 |
| 2026-03-30 00:00 |
20:23:01.19 |
-70:59:39.8 |
HIP 100466 |
12.45 |
| 2026-03-30 12:00 |
20:23:04.98 |
-71:00:05.6 |
HIP 100466 |
12.11 |
| 2026-03-31 00:00 |
20:23:08.69 |
-71:00:31.7 |
HIP 100466 |
11.78 |
| 2026-03-31 12:00 |
20:23:12.34 |
-71:00:57.8 |
HIP 100466 |
11.46 |
| 2026-04-01 00:00 |
20:23:15.93 |
-71:01:24.2 |
HIP 100466 |
11.15 |
| 2026-04-01 12:00 |
20:23:19.45 |
-71:01:50.7 |
HIP 100466 |
10.85 |
| 2026-04-02 00:00 |
20:23:22.90 |
-71:02:17.4 |
HIP 100466 |
10.57 |
| 2026-04-02 12:00 |
20:23:26.28 |
-71:02:44.2 |
HIP 100466 |
10.30 |
| 2026-04-03 00:00 |
20:23:29.60 |
-71:03:11.2 |
HIP 100466 |
10.04 |
| 2026-04-03 12:00 |
20:23:32.85 |
-71:03:38.4 |
HIP 100466 |
9.80 |
| 2026-04-04 00:00 |
20:23:36.03 |
-71:04:05.7 |
HIP 100466 |
9.58 |
| 2026-04-04 12:00 |
20:23:39.14 |
-71:04:33.2 |
HIP 100466 |
9.38 |
| 2026-04-05 00:00 |
20:23:42.18 |
-71:05:00.8 |
HIP 100466 |
9.19 |
| 2026-04-05 12:00 |
20:23:45.15 |
-71:05:28.6 |
HIP 100466 |
9.03 |
| 2026-04-06 00:00 |
20:23:48.06 |
-71:05:56.5 |
HIP 100466 |
8.89 |
| 2026-04-06 12:00 |
20:23:50.89 |
-71:06:24.6 |
HIP 100466 |
8.77 |
| 2026-04-07 00:00 |
20:23:53.66 |
-71:06:52.8 |
HIP 100466 |
8.67 |
| 2026-04-07 12:00 |
20:23:56.35 |
-71:07:21.2 |
HIP 100466 |
8.60 |
| 2026-04-08 00:00 |
20:23:58.98 |
-71:07:49.7 |
HIP 100466 |
8.55 |
| 2026-04-08 12:00 |
20:24:01.53 |
-71:08:18.3 |
HIP 100466 |
8.53 |
| 2026-04-09 00:00 |
20:24:04.01 |
-71:08:47.1 |
HIP 100466 |
8.53 |
| 2026-04-09 12:00 |
20:24:06.42 |
-71:09:16.0 |
HIP 100466 |
8.56 |
| 2026-04-10 00:00 |
20:24:08.76 |
-71:09:45.1 |
HIP 100466 |
8.61 |
| 2026-04-10 12:00 |
20:24:11.03 |
-71:10:14.2 |
HIP 100466 |
8.69 |
| 2026-04-11 00:00 |
20:24:13.23 |
-71:10:43.5 |
HIP 100466 |
8.79 |
| 2026-04-11 12:00 |
20:24:15.35 |
-71:11:13.0 |
HIP 100466 |
8.92 |
| 2026-04-12 00:00 |
20:24:17.40 |
-71:11:42.5 |
HIP 100466 |
9.06 |
| 2026-04-12 12:00 |
20:24:19.38 |
-71:12:12.2 |
HIP 100466 |
9.23 |
| 2026-04-13 00:00 |
20:24:21.29 |
-71:12:42.0 |
HIP 100466 |
9.42 |
| 2026-04-13 12:00 |
20:24:23.12 |
-71:13:11.9 |
HIP 100466 |
9.63 |
| 2026-04-14 00:00 |
20:24:24.88 |
-71:13:42.0 |
HIP 100466 |
9.85 |
| 2026-04-14 12:00 |
20:24:26.56 |
-71:14:12.1 |
HIP 100466 |
10.09 |
| 2026-04-15 00:00 |
20:24:28.17 |
-71:14:42.4 |
HIP 100466 |
10.35 |
| 2026-04-15 12:00 |
20:24:29.71 |
-71:15:12.7 |
HIP 100466 |
10.62 |
| 2026-04-16 00:00 |
20:24:31.17 |
-71:15:43.2 |
HIP 100466 |
10.90 |