P/2020 WJ5 (Lemmon)
| Parameter |
Value |
| Designation |
P/2020 WJ5 (Lemmon) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-07-01T10:23:55.633920Z |
| Orbit solution date (soln_date, UTC) |
2024-08-11T00:12:20Z |
| Obs used |
720 |
| NEO |
- |
| M1 |
12.300 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2022-12-17.0000000 |
| e |
0.17132992 |
| q (au) |
4.985837 |
| a (au) |
6.016673 |
| i (deg) |
22.294439 |
| Ω (om, deg) |
177.810718 |
| ω (w, deg) |
338.229837 |
| M (ma, deg) |
35.633474 |
Magnitude
Scatter + Global Linear
$$
M_a = (3.028 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
3.028 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.997 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
19:14:34.17 |
-03:23:35.4 |
HIP 94433 |
20.50 |
| 2026-02-03 12:00 |
19:14:54.52 |
-03:22:33.9 |
HIP 94638 |
17.68 |
| 2026-02-04 00:00 |
19:15:14.81 |
-03:21:31.9 |
HIP 94638 |
15.00 |
| 2026-02-04 12:00 |
19:15:35.05 |
-03:20:29.3 |
HIP 94638 |
13.81 |
| 2026-02-05 00:00 |
19:15:55.25 |
-03:19:26.1 |
HIP 94638 |
14.46 |
| 2026-02-05 12:00 |
19:16:15.39 |
-03:18:22.4 |
HIP 94638 |
16.73 |
| 2026-02-06 00:00 |
19:16:35.48 |
-03:17:18.2 |
HIP 94638 |
20.07 |
| 2026-02-06 12:00 |
19:16:55.51 |
-03:16:13.4 |
HIP 94638 |
24.03 |
| 2026-02-07 00:00 |
19:17:15.50 |
-03:15:08.0 |
HIP 94638 |
28.36 |
| 2026-02-07 12:00 |
19:17:35.43 |
-03:14:02.1 |
HIP 94638 |
32.89 |
| 2026-02-08 00:00 |
19:17:55.30 |
-03:12:55.6 |
HIP 95031 |
34.67 |
| 2026-02-08 12:00 |
19:18:15.12 |
-03:11:48.6 |
HIP 95031 |
29.61 |
| 2026-02-09 00:00 |
19:18:34.88 |
-03:10:41.1 |
HIP 95031 |
24.57 |
| 2026-02-09 12:00 |
19:18:54.59 |
-03:09:33.0 |
HIP 95031 |
19.54 |
| 2026-02-10 00:00 |
19:19:14.24 |
-03:08:24.4 |
HIP 95031 |
14.55 |
| 2026-02-10 12:00 |
19:19:33.83 |
-03:07:15.3 |
HIP 95031 |
9.60 |
| 2026-02-11 00:00 |
19:19:53.36 |
-03:06:05.6 |
HIP 95031 |
4.82 |
| 2026-02-11 12:00 |
19:20:12.83 |
-03:04:55.4 |
HIP 95031 |
2.11 |
| 2026-02-12 00:00 |
19:20:32.24 |
-03:03:44.7 |
HIP 95031 |
5.96 |
| 2026-02-12 12:00 |
19:20:51.59 |
-03:02:33.5 |
HIP 95031 |
10.77 |
| 2026-02-13 00:00 |
19:21:10.88 |
-03:01:21.8 |
HIP 95031 |
15.67 |
| 2026-02-13 12:00 |
19:21:30.11 |
-03:00:09.6 |
HIP 95031 |
20.58 |
| 2026-02-14 00:00 |
19:21:49.27 |
-02:58:56.8 |
HIP 95257 |
16.25 |
| 2026-02-14 12:00 |
19:22:08.36 |
-02:57:43.6 |
HIP 95257 |
11.39 |
| 2026-02-15 00:00 |
19:22:27.39 |
-02:56:29.9 |
HIP 95257 |
6.61 |
| 2026-02-15 12:00 |
19:22:46.36 |
-02:55:15.6 |
HIP 95257 |
2.44 |
| 2026-02-16 00:00 |
19:23:05.26 |
-02:54:00.9 |
HIP 95257 |
3.99 |
| 2026-02-16 12:00 |
19:23:24.09 |
-02:52:45.7 |
HIP 95257 |
8.56 |
| 2026-02-17 00:00 |
19:23:42.86 |
-02:51:30.1 |
HIP 95257 |
13.33 |
| 2026-02-17 12:00 |
19:24:01.55 |
-02:50:13.9 |
HIP 95257 |
18.12 |
| 2026-02-18 00:00 |
19:24:20.18 |
-02:48:57.3 |
HIP 95257 |
22.92 |
| 2026-02-18 12:00 |
19:24:38.73 |
-02:47:40.2 |
HIP 95257 |
27.71 |
| 2026-02-19 00:00 |
19:24:57.21 |
-02:46:22.7 |
HIP 95257 |
32.49 |
| 2026-02-19 12:00 |
19:25:15.63 |
-02:45:04.7 |
HIP 95257 |
37.26 |
| 2026-02-20 00:00 |
19:25:33.97 |
-02:43:46.3 |
HIP 95511 |
40.12 |
| 2026-02-20 12:00 |
19:25:52.23 |
-02:42:27.4 |
HIP 95511 |
38.95 |
| 2026-02-21 00:00 |
19:26:10.42 |
-02:41:08.0 |
HIP 95511 |
38.33 |
| 2026-02-21 12:00 |
19:26:28.54 |
-02:39:48.3 |
HIP 95511 |
38.27 |
| 2026-02-22 00:00 |
19:26:46.58 |
-02:38:28.0 |
HIP 95651 |
38.32 |
| 2026-02-22 12:00 |
19:27:04.55 |
-02:37:07.4 |
HIP 95651 |
36.18 |
| 2026-02-23 00:00 |
19:27:22.44 |
-02:35:46.4 |
HIP 95824 |
32.90 |
| 2026-02-23 12:00 |
19:27:40.25 |
-02:34:24.9 |
HIP 95824 |
29.47 |
| 2026-02-24 00:00 |
19:27:57.98 |
-02:33:03.0 |
HIP 95824 |
26.43 |