C/2004 X2 (LINEAR)
| 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) |
| 2026-02-03 00:00 |
20:10:48.08 |
-70:35:18.7 |
HIP 99776 |
19.36 |
| 2026-02-03 12:00 |
20:10:56.68 |
-70:35:17.7 |
HIP 99776 |
18.67 |
| 2026-02-04 00:00 |
20:11:05.27 |
-70:35:17.0 |
HIP 99776 |
17.98 |
| 2026-02-04 12:00 |
20:11:13.83 |
-70:35:16.5 |
HIP 99776 |
17.30 |
| 2026-02-05 00:00 |
20:11:22.38 |
-70:35:16.4 |
HIP 99776 |
16.61 |
| 2026-02-05 12:00 |
20:11:30.91 |
-70:35:16.5 |
HIP 99776 |
15.93 |
| 2026-02-06 00:00 |
20:11:39.42 |
-70:35:16.9 |
HIP 99776 |
15.25 |
| 2026-02-06 12:00 |
20:11:47.91 |
-70:35:17.6 |
HIP 99776 |
14.58 |
| 2026-02-07 00:00 |
20:11:56.38 |
-70:35:18.5 |
HIP 99776 |
13.91 |
| 2026-02-07 12:00 |
20:12:04.82 |
-70:35:19.8 |
HIP 99776 |
13.24 |
| 2026-02-08 00:00 |
20:12:13.25 |
-70:35:21.3 |
HIP 99776 |
12.58 |
| 2026-02-08 12:00 |
20:12:21.65 |
-70:35:23.1 |
HIP 99776 |
11.91 |
| 2026-02-09 00:00 |
20:12:30.03 |
-70:35:25.2 |
HIP 99776 |
11.26 |
| 2026-02-09 12:00 |
20:12:38.39 |
-70:35:27.5 |
HIP 99776 |
10.61 |
| 2026-02-10 00:00 |
20:12:46.72 |
-70:35:30.1 |
HIP 99776 |
9.96 |
| 2026-02-10 12:00 |
20:12:55.03 |
-70:35:33.1 |
HIP 99776 |
9.32 |
| 2026-02-11 00:00 |
20:13:03.31 |
-70:35:36.2 |
HIP 99776 |
8.69 |
| 2026-02-11 12:00 |
20:13:11.57 |
-70:35:39.7 |
HIP 99776 |
8.06 |
| 2026-02-12 00:00 |
20:13:19.80 |
-70:35:43.4 |
HIP 99776 |
7.45 |
| 2026-02-12 12:00 |
20:13:28.00 |
-70:35:47.5 |
HIP 99776 |
6.85 |
| 2026-02-13 00:00 |
20:13:36.18 |
-70:35:51.8 |
HIP 99776 |
6.27 |
| 2026-02-13 12:00 |
20:13:44.33 |
-70:35:56.3 |
HIP 99776 |
5.70 |
| 2026-02-14 00:00 |
20:13:52.46 |
-70:36:01.2 |
HIP 99776 |
5.17 |
| 2026-02-14 12:00 |
20:14:00.55 |
-70:36:06.3 |
HIP 99776 |
4.67 |
| 2026-02-15 00:00 |
20:14:08.61 |
-70:36:11.7 |
HIP 99776 |
4.21 |
| 2026-02-15 12:00 |
20:14:16.65 |
-70:36:17.4 |
HIP 99776 |
3.82 |
| 2026-02-16 00:00 |
20:14:24.65 |
-70:36:23.4 |
HIP 99776 |
3.50 |
| 2026-02-16 12:00 |
20:14:32.63 |
-70:36:29.6 |
HIP 99776 |
3.30 |
| 2026-02-17 00:00 |
20:14:40.57 |
-70:36:36.1 |
HIP 99776 |
3.21 |
| 2026-02-17 12:00 |
20:14:48.48 |
-70:36:42.9 |
HIP 99776 |
3.26 |
| 2026-02-18 00:00 |
20:14:56.36 |
-70:36:49.9 |
HIP 99776 |
3.43 |
| 2026-02-18 12:00 |
20:15:04.20 |
-70:36:57.2 |
HIP 99776 |
3.71 |
| 2026-02-19 00:00 |
20:15:12.01 |
-70:37:04.8 |
HIP 99776 |
4.08 |
| 2026-02-19 12:00 |
20:15:19.79 |
-70:37:12.7 |
HIP 99776 |
4.50 |
| 2026-02-20 00:00 |
20:15:27.53 |
-70:37:20.9 |
HIP 99776 |
4.98 |
| 2026-02-20 12:00 |
20:15:35.24 |
-70:37:29.3 |
HIP 99776 |
5.48 |
| 2026-02-21 00:00 |
20:15:42.91 |
-70:37:38.0 |
HIP 99776 |
6.01 |
| 2026-02-21 12:00 |
20:15:50.55 |
-70:37:46.9 |
HIP 99776 |
6.56 |
| 2026-02-22 00:00 |
20:15:58.15 |
-70:37:56.1 |
HIP 99776 |
7.12 |
| 2026-02-22 12:00 |
20:16:05.71 |
-70:38:05.6 |
HIP 99776 |
7.69 |
| 2026-02-23 00:00 |
20:16:13.23 |
-70:38:15.4 |
HIP 99776 |
8.27 |
| 2026-02-23 12:00 |
20:16:20.72 |
-70:38:25.4 |
HIP 99776 |
8.85 |
| 2026-02-24 00:00 |
20:16:28.17 |
-70:38:35.7 |
HIP 99776 |
9.43 |