C/2005 W2 (Christensen)
| 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) |
| 2026-02-03 00:00 |
16:34:36.75 |
-33:09:36.5 |
HIP 81143 |
8.69 |
| 2026-02-03 12:00 |
16:34:39.42 |
-33:09:52.3 |
HIP 81143 |
8.67 |
| 2026-02-04 00:00 |
16:34:42.06 |
-33:10:08.0 |
HIP 81143 |
8.69 |
| 2026-02-04 12:00 |
16:34:44.66 |
-33:10:23.8 |
HIP 81143 |
8.76 |
| 2026-02-05 00:00 |
16:34:47.22 |
-33:10:39.5 |
HIP 81143 |
8.85 |
| 2026-02-05 12:00 |
16:34:49.74 |
-33:10:55.2 |
HIP 81143 |
8.99 |
| 2026-02-06 00:00 |
16:34:52.22 |
-33:11:10.8 |
HIP 81143 |
9.15 |
| 2026-02-06 12:00 |
16:34:54.67 |
-33:11:26.5 |
HIP 81143 |
9.34 |
| 2026-02-07 00:00 |
16:34:57.07 |
-33:11:42.1 |
HIP 81143 |
9.55 |
| 2026-02-07 12:00 |
16:34:59.44 |
-33:11:57.7 |
HIP 81143 |
9.79 |
| 2026-02-08 00:00 |
16:35:01.77 |
-33:12:13.2 |
HIP 81143 |
10.05 |
| 2026-02-08 12:00 |
16:35:04.05 |
-33:12:28.8 |
HIP 81143 |
10.32 |
| 2026-02-09 00:00 |
16:35:06.30 |
-33:12:44.3 |
HIP 81143 |
10.60 |
| 2026-02-09 12:00 |
16:35:08.51 |
-33:12:59.7 |
HIP 81143 |
10.90 |
| 2026-02-10 00:00 |
16:35:10.68 |
-33:13:15.2 |
HIP 81143 |
11.21 |
| 2026-02-10 12:00 |
16:35:12.81 |
-33:13:30.6 |
HIP 81143 |
11.52 |
| 2026-02-11 00:00 |
16:35:14.90 |
-33:13:46.0 |
HIP 81143 |
11.84 |
| 2026-02-11 12:00 |
16:35:16.95 |
-33:14:01.3 |
HIP 81143 |
12.17 |
| 2026-02-12 00:00 |
16:35:18.96 |
-33:14:16.6 |
HIP 81143 |
12.50 |
| 2026-02-12 12:00 |
16:35:20.93 |
-33:14:31.9 |
HIP 81143 |
12.83 |
| 2026-02-13 00:00 |
16:35:22.86 |
-33:14:47.1 |
HIP 81143 |
13.16 |
| 2026-02-13 12:00 |
16:35:24.74 |
-33:15:02.3 |
HIP 81143 |
13.49 |
| 2026-02-14 00:00 |
16:35:26.59 |
-33:15:17.5 |
HIP 81143 |
13.82 |
| 2026-02-14 12:00 |
16:35:28.39 |
-33:15:32.6 |
HIP 81143 |
14.15 |
| 2026-02-15 00:00 |
16:35:30.15 |
-33:15:47.7 |
HIP 81143 |
14.48 |
| 2026-02-15 12:00 |
16:35:31.87 |
-33:16:02.7 |
HIP 81143 |
14.81 |
| 2026-02-16 00:00 |
16:35:33.55 |
-33:16:17.7 |
HIP 81143 |
15.13 |
| 2026-02-16 12:00 |
16:35:35.19 |
-33:16:32.7 |
HIP 81143 |
15.45 |
| 2026-02-17 00:00 |
16:35:36.79 |
-33:16:47.6 |
HIP 81143 |
15.77 |
| 2026-02-17 12:00 |
16:35:38.34 |
-33:17:02.4 |
HIP 81143 |
16.08 |
| 2026-02-18 00:00 |
16:35:39.85 |
-33:17:17.2 |
HIP 81143 |
16.39 |
| 2026-02-18 12:00 |
16:35:41.32 |
-33:17:32.0 |
HIP 81143 |
16.69 |
| 2026-02-19 00:00 |
16:35:42.75 |
-33:17:46.7 |
HIP 81143 |
16.99 |
| 2026-02-19 12:00 |
16:35:44.13 |
-33:18:01.4 |
HIP 81143 |
17.28 |
| 2026-02-20 00:00 |
16:35:45.47 |
-33:18:16.0 |
HIP 81143 |
17.57 |
| 2026-02-20 12:00 |
16:35:46.77 |
-33:18:30.5 |
HIP 81143 |
17.85 |
| 2026-02-21 00:00 |
16:35:48.03 |
-33:18:45.0 |
HIP 81143 |
18.12 |
| 2026-02-21 12:00 |
16:35:49.24 |
-33:18:59.5 |
HIP 81143 |
18.39 |
| 2026-02-22 00:00 |
16:35:50.41 |
-33:19:13.9 |
HIP 81143 |
18.65 |
| 2026-02-22 12:00 |
16:35:51.54 |
-33:19:28.2 |
HIP 81143 |
18.91 |
| 2026-02-23 00:00 |
16:35:52.62 |
-33:19:42.5 |
HIP 81143 |
19.16 |
| 2026-02-23 12:00 |
16:35:53.66 |
-33:19:56.7 |
HIP 81143 |
19.40 |
| 2026-02-24 00:00 |
16:35:54.66 |
-33:20:10.9 |
HIP 81143 |
19.63 |