| 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 |
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) |
| 2026-07-29 00:00 |
20:05:21.98 |
-72:33:36.8 |
HIP 99338 |
23.07 |
| 2026-07-29 12:00 |
20:05:12.61 |
-72:33:34.9 |
HIP 99338 |
23.69 |
| 2026-07-30 00:00 |
20:05:03.24 |
-72:33:32.7 |
HIP 99338 |
24.31 |
| 2026-07-30 12:00 |
20:04:53.89 |
-72:33:30.2 |
HIP 99338 |
24.93 |
| 2026-07-31 00:00 |
20:04:44.55 |
-72:33:27.3 |
HIP 99338 |
25.56 |
| 2026-07-31 12:00 |
20:04:35.23 |
-72:33:24.1 |
HIP 99338 |
26.20 |
| 2026-08-01 00:00 |
20:04:25.92 |
-72:33:20.6 |
HIP 99338 |
26.84 |
| 2026-08-01 12:00 |
20:04:16.62 |
-72:33:16.8 |
HIP 98495 |
26.92 |
| 2026-08-02 00:00 |
20:04:07.35 |
-72:33:12.7 |
HIP 98495 |
26.56 |
| 2026-08-02 12:00 |
20:03:58.09 |
-72:33:08.2 |
HIP 98495 |
26.22 |
| 2026-08-03 00:00 |
20:03:48.85 |
-72:33:03.4 |
HIP 98495 |
25.90 |
| 2026-08-03 12:00 |
20:03:39.63 |
-72:32:58.3 |
HIP 98495 |
25.60 |
| 2026-08-04 00:00 |
20:03:30.43 |
-72:32:52.8 |
HIP 98495 |
25.32 |
| 2026-08-04 12:00 |
20:03:21.24 |
-72:32:47.1 |
HIP 98495 |
25.06 |
| 2026-08-05 00:00 |
20:03:12.09 |
-72:32:41.0 |
HIP 98495 |
24.82 |
| 2026-08-05 12:00 |
20:03:02.95 |
-72:32:34.6 |
HIP 98495 |
24.61 |
| 2026-08-06 00:00 |
20:02:53.83 |
-72:32:27.9 |
HIP 98495 |
24.41 |
| 2026-08-06 12:00 |
20:02:44.75 |
-72:32:20.8 |
HIP 98495 |
24.25 |
| 2026-08-07 00:00 |
20:02:35.68 |
-72:32:13.5 |
HIP 98495 |
24.10 |
| 2026-08-07 12:00 |
20:02:26.64 |
-72:32:05.8 |
HIP 98495 |
23.98 |
| 2026-08-08 00:00 |
20:02:17.63 |
-72:31:57.8 |
HIP 98495 |
23.89 |
| 2026-08-08 12:00 |
20:02:08.64 |
-72:31:49.4 |
HIP 98495 |
23.82 |
| 2026-08-09 00:00 |
20:01:59.68 |
-72:31:40.8 |
HIP 98495 |
23.77 |
| 2026-08-09 12:00 |
20:01:50.76 |
-72:31:31.8 |
HIP 98495 |
23.75 |
| 2026-08-10 00:00 |
20:01:41.86 |
-72:31:22.6 |
HIP 98495 |
23.75 |
| 2026-08-10 12:00 |
20:01:32.99 |
-72:31:13.0 |
HIP 98495 |
23.78 |
| 2026-08-11 00:00 |
20:01:24.15 |
-72:31:03.0 |
HIP 98495 |
23.84 |
| 2026-08-11 12:00 |
20:01:15.35 |
-72:30:52.8 |
HIP 98495 |
23.92 |
| 2026-08-12 00:00 |
20:01:06.57 |
-72:30:42.3 |
HIP 98106 |
23.64 |
| 2026-08-12 12:00 |
20:00:57.84 |
-72:30:31.4 |
HIP 98106 |
22.96 |
| 2026-08-13 00:00 |
20:00:49.13 |
-72:30:20.2 |
HIP 98106 |
22.29 |
| 2026-08-13 12:00 |
20:00:40.46 |
-72:30:08.8 |
HIP 98106 |
21.61 |
| 2026-08-14 00:00 |
20:00:31.83 |
-72:29:57.0 |
HIP 98106 |
20.94 |
| 2026-08-14 12:00 |
20:00:23.24 |
-72:29:44.9 |
HIP 98106 |
20.26 |
| 2026-08-15 00:00 |
20:00:14.68 |
-72:29:32.4 |
HIP 98106 |
19.59 |
| 2026-08-15 12:00 |
20:00:06.17 |
-72:29:19.7 |
HIP 98106 |
18.92 |
| 2026-08-16 00:00 |
19:59:57.69 |
-72:29:06.7 |
HIP 98106 |
18.24 |
| 2026-08-16 12:00 |
19:59:49.25 |
-72:28:53.4 |
HIP 98106 |
17.57 |
| 2026-08-17 00:00 |
19:59:40.85 |
-72:28:39.7 |
HIP 98106 |
16.90 |
| 2026-08-17 12:00 |
19:59:32.50 |
-72:28:25.8 |
HIP 98106 |
16.23 |
| 2026-08-18 00:00 |
19:59:24.18 |
-72:28:11.5 |
HIP 98106 |
15.57 |
| 2026-08-18 12:00 |
19:59:15.91 |
-72:27:57.0 |
HIP 98106 |
14.90 |
| 2026-08-19 00:00 |
19:59:07.69 |
-72:27:42.2 |
HIP 98106 |
14.23 |