| Parameter |
Value |
| Designation |
C/2005 W2 (Christensen) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2006-03-27T09:29:05.815680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:54Z |
| Obs used |
219 |
| NEO |
- |
| M1 |
13.800 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2005-12-19.0000000 |
| e |
0.82445359 |
| q (au) |
3.331620 |
| a (au) |
18.978569 |
| i (deg) |
11.264027 |
| Ω (om, deg) |
336.615180 |
| ω (w, deg) |
111.670116 |
| M (ma, deg) |
358.827041 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.408 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.408 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
1.000 |
| 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 |
16:35:35.06 |
-33:31:57.0 |
HIP 81194 |
9.51 |
| 2026-03-26 12:00 |
16:35:33.43 |
-33:32:05.8 |
HIP 81194 |
9.18 |
| 2026-03-27 00:00 |
16:35:31.76 |
-33:32:14.5 |
HIP 81194 |
8.84 |
| 2026-03-27 12:00 |
16:35:30.04 |
-33:32:23.0 |
HIP 81194 |
8.50 |
| 2026-03-28 00:00 |
16:35:28.29 |
-33:32:31.5 |
HIP 81194 |
8.17 |
| 2026-03-28 12:00 |
16:35:26.49 |
-33:32:39.8 |
HIP 81194 |
7.83 |
| 2026-03-29 00:00 |
16:35:24.66 |
-33:32:48.0 |
HIP 81194 |
7.50 |
| 2026-03-29 12:00 |
16:35:22.79 |
-33:32:56.1 |
HIP 81194 |
7.18 |
| 2026-03-30 00:00 |
16:35:20.87 |
-33:33:04.1 |
HIP 81194 |
6.86 |
| 2026-03-30 12:00 |
16:35:18.92 |
-33:33:12.0 |
HIP 81194 |
6.55 |
| 2026-03-31 00:00 |
16:35:16.93 |
-33:33:19.7 |
HIP 81194 |
6.25 |
| 2026-03-31 12:00 |
16:35:14.90 |
-33:33:27.3 |
HIP 81194 |
5.97 |
| 2026-04-01 00:00 |
16:35:12.82 |
-33:33:34.8 |
HIP 81194 |
5.70 |
| 2026-04-01 12:00 |
16:35:10.72 |
-33:33:42.2 |
HIP 81194 |
5.46 |
| 2026-04-02 00:00 |
16:35:08.57 |
-33:33:49.5 |
HIP 81194 |
5.26 |
| 2026-04-02 12:00 |
16:35:06.38 |
-33:33:56.6 |
HIP 81194 |
5.08 |
| 2026-04-03 00:00 |
16:35:04.16 |
-33:34:03.6 |
HIP 81194 |
4.95 |
| 2026-04-03 12:00 |
16:35:01.89 |
-33:34:10.5 |
HIP 81194 |
4.86 |
| 2026-04-04 00:00 |
16:34:59.59 |
-33:34:17.2 |
HIP 81194 |
4.83 |
| 2026-04-04 12:00 |
16:34:57.25 |
-33:34:23.8 |
HIP 81194 |
4.85 |
| 2026-04-05 00:00 |
16:34:54.88 |
-33:34:30.3 |
HIP 81194 |
4.92 |
| 2026-04-05 12:00 |
16:34:52.46 |
-33:34:36.7 |
HIP 81194 |
5.05 |
| 2026-04-06 00:00 |
16:34:50.01 |
-33:34:43.0 |
HIP 81194 |
5.24 |
| 2026-04-06 12:00 |
16:34:47.52 |
-33:34:49.1 |
HIP 81194 |
5.47 |
| 2026-04-07 00:00 |
16:34:45.00 |
-33:34:55.1 |
HIP 81194 |
5.75 |
| 2026-04-07 12:00 |
16:34:42.44 |
-33:35:00.9 |
HIP 81194 |
6.08 |
| 2026-04-08 00:00 |
16:34:39.84 |
-33:35:06.6 |
HIP 81194 |
6.44 |
| 2026-04-08 12:00 |
16:34:37.21 |
-33:35:12.2 |
HIP 81194 |
6.83 |
| 2026-04-09 00:00 |
16:34:34.54 |
-33:35:17.7 |
HIP 81194 |
7.25 |
| 2026-04-09 12:00 |
16:34:31.83 |
-33:35:23.0 |
HIP 81194 |
7.70 |
| 2026-04-10 00:00 |
16:34:29.09 |
-33:35:28.2 |
HIP 81194 |
8.17 |
| 2026-04-10 12:00 |
16:34:26.31 |
-33:35:33.3 |
HIP 81194 |
8.66 |
| 2026-04-11 00:00 |
16:34:23.50 |
-33:35:38.2 |
HIP 81194 |
9.17 |
| 2026-04-11 12:00 |
16:34:20.65 |
-33:35:43.0 |
HIP 81194 |
9.69 |
| 2026-04-12 00:00 |
16:34:17.77 |
-33:35:47.7 |
HIP 81194 |
10.23 |
| 2026-04-12 12:00 |
16:34:14.86 |
-33:35:52.2 |
HIP 81194 |
10.79 |
| 2026-04-13 00:00 |
16:34:11.91 |
-33:35:56.6 |
HIP 81194 |
11.36 |
| 2026-04-13 12:00 |
16:34:08.92 |
-33:36:00.8 |
HIP 81194 |
11.94 |
| 2026-04-14 00:00 |
16:34:05.90 |
-33:36:04.9 |
HIP 81194 |
12.53 |
| 2026-04-14 12:00 |
16:34:02.85 |
-33:36:08.9 |
HIP 81194 |
13.14 |
| 2026-04-15 00:00 |
16:33:59.77 |
-33:36:12.7 |
HIP 81194 |
13.75 |
| 2026-04-15 12:00 |
16:33:56.65 |
-33:36:16.4 |
HIP 81194 |
14.37 |
| 2026-04-16 00:00 |
16:33:53.50 |
-33:36:20.0 |
HIP 81194 |
15.01 |