| Parameter |
Value |
| Designation |
C/2006 WD4 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2007-04-28T09:33:26.683200Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:02Z |
| Obs used |
96 |
| NEO |
- |
| M1 |
17.200 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2007-01-20.0000000 |
| e |
0.99898724 |
| q (au) |
0.591244 |
| a (au) |
583.797842 |
| i (deg) |
152.704616 |
| Ω (om, deg) |
226.790541 |
| ω (w, deg) |
292.690897 |
| M (ma, deg) |
359.993125 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.923 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.923 |
| n |
2.000 |
| gf |
0.800 |
| gb |
-1.000 |
| k |
0.800 |
| δ90 |
1.000 |
| 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) |
| 2026-09-25 00:00 |
09:18:53.09 |
+43:36:54.3 |
HIP 45555 |
37.44 |
| 2026-09-25 12:00 |
09:18:55.67 |
+43:37:01.2 |
HIP 45555 |
37.79 |
| 2026-09-26 00:00 |
09:18:58.23 |
+43:37:08.2 |
HIP 45555 |
38.14 |
| 2026-09-26 12:00 |
09:19:00.76 |
+43:37:15.5 |
HIP 45555 |
38.49 |
| 2026-09-27 00:00 |
09:19:03.28 |
+43:37:23.0 |
HIP 45979 |
38.32 |
| 2026-09-27 12:00 |
09:19:05.77 |
+43:37:30.6 |
HIP 45979 |
37.88 |
| 2026-09-28 00:00 |
09:19:08.23 |
+43:37:38.5 |
HIP 45979 |
37.44 |
| 2026-09-28 12:00 |
09:19:10.68 |
+43:37:46.5 |
HIP 45979 |
37.00 |
| 2026-09-29 00:00 |
09:19:13.10 |
+43:37:54.7 |
HIP 45979 |
36.57 |
| 2026-09-29 12:00 |
09:19:15.49 |
+43:38:03.1 |
HIP 45979 |
36.14 |
| 2026-09-30 00:00 |
09:19:17.86 |
+43:38:11.8 |
HIP 45979 |
35.72 |
| 2026-09-30 12:00 |
09:19:20.21 |
+43:38:20.6 |
HIP 45979 |
35.30 |
| 2026-10-01 00:00 |
09:19:22.54 |
+43:38:29.6 |
HIP 45979 |
34.89 |
| 2026-10-01 12:00 |
09:19:24.83 |
+43:38:38.7 |
HIP 45979 |
34.48 |
| 2026-10-02 00:00 |
09:19:27.11 |
+43:38:48.1 |
HIP 45979 |
34.08 |
| 2026-10-02 12:00 |
09:19:29.36 |
+43:38:57.7 |
HIP 45979 |
33.69 |
| 2026-10-03 00:00 |
09:19:31.58 |
+43:39:07.4 |
HIP 45979 |
33.30 |
| 2026-10-03 12:00 |
09:19:33.78 |
+43:39:17.4 |
HIP 45979 |
32.92 |
| 2026-10-04 00:00 |
09:19:35.95 |
+43:39:27.5 |
HIP 45979 |
32.54 |
| 2026-10-04 12:00 |
09:19:38.10 |
+43:39:37.9 |
HIP 45979 |
32.17 |
| 2026-10-05 00:00 |
09:19:40.22 |
+43:39:48.4 |
HIP 45979 |
31.81 |
| 2026-10-05 12:00 |
09:19:42.32 |
+43:39:59.1 |
HIP 45979 |
31.45 |
| 2026-10-06 00:00 |
09:19:44.39 |
+43:40:10.0 |
HIP 45979 |
31.10 |
| 2026-10-06 12:00 |
09:19:46.43 |
+43:40:21.0 |
HIP 45979 |
30.75 |
| 2026-10-07 00:00 |
09:19:48.44 |
+43:40:32.3 |
HIP 45979 |
30.42 |
| 2026-10-07 12:00 |
09:19:50.43 |
+43:40:43.8 |
HIP 45979 |
30.09 |
| 2026-10-08 00:00 |
09:19:52.39 |
+43:40:55.4 |
HIP 45979 |
29.77 |
| 2026-10-08 12:00 |
09:19:54.33 |
+43:41:07.2 |
HIP 45979 |
29.45 |
| 2026-10-09 00:00 |
09:19:56.24 |
+43:41:19.2 |
HIP 45979 |
29.14 |
| 2026-10-09 12:00 |
09:19:58.11 |
+43:41:31.4 |
HIP 45979 |
28.84 |
| 2026-10-10 00:00 |
09:19:59.97 |
+43:41:43.8 |
HIP 45979 |
28.55 |
| 2026-10-10 12:00 |
09:20:01.79 |
+43:41:56.4 |
HIP 45979 |
28.27 |
| 2026-10-11 00:00 |
09:20:03.58 |
+43:42:09.1 |
HIP 45979 |
27.99 |
| 2026-10-11 12:00 |
09:20:05.35 |
+43:42:22.1 |
HIP 45979 |
27.73 |
| 2026-10-12 00:00 |
09:20:07.09 |
+43:42:35.2 |
HIP 45979 |
27.47 |
| 2026-10-12 12:00 |
09:20:08.80 |
+43:42:48.5 |
HIP 45979 |
27.22 |
| 2026-10-13 00:00 |
09:20:10.48 |
+43:43:01.9 |
HIP 45979 |
26.98 |
| 2026-10-13 12:00 |
09:20:12.13 |
+43:43:15.6 |
HIP 45979 |
26.75 |
| 2026-10-14 00:00 |
09:20:13.75 |
+43:43:29.4 |
HIP 45979 |
26.53 |
| 2026-10-14 12:00 |
09:20:15.34 |
+43:43:43.4 |
HIP 45979 |
26.31 |
| 2026-10-15 00:00 |
09:20:16.91 |
+43:43:57.6 |
HIP 45979 |
26.11 |
| 2026-10-15 12:00 |
09:20:18.44 |
+43:44:11.9 |
HIP 45979 |
25.92 |
| 2026-10-16 00:00 |
09:20:19.94 |
+43:44:26.5 |
HIP 45979 |
25.73 |