| Parameter |
Value |
| Designation |
C/2020 W5 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-11-30T01:54:40.083840Z |
| Orbit solution date (soln_date, UTC) |
2025-01-10T09:12:15Z |
| Obs used |
55 |
| NEO |
- |
| M1 |
14.200 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-11-20T05:24:13.046400Z |
| Discovery magnitude (MPC) |
21.61 G |
| Discovery observatory (MPC) |
G96 · Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-11-30.0000000 |
| e |
1.00164978 |
| q (au) |
3.364485 |
| a (au) |
-2039.359232 |
| i (deg) |
88.594700 |
| Ω (om, deg) |
75.516670 |
| ω (w, deg) |
24.475527 |
| M (ma, deg) |
-0.000001 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.215 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.215 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.960 |
| 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) |
| 2026-03-26 00:00 |
17:23:06.52 |
+10:43:06.3 |
HIP 85087 |
10.74 |
| 2026-03-26 12:00 |
17:23:04.33 |
+10:43:53.2 |
HIP 85087 |
10.30 |
| 2026-03-27 00:00 |
17:23:02.07 |
+10:44:40.0 |
HIP 85087 |
9.93 |
| 2026-03-27 12:00 |
17:22:59.74 |
+10:45:26.7 |
HIP 85087 |
9.66 |
| 2026-03-28 00:00 |
17:22:57.33 |
+10:46:13.4 |
HIP 85087 |
9.49 |
| 2026-03-28 12:00 |
17:22:54.86 |
+10:47:00.0 |
HIP 85087 |
9.44 |
| 2026-03-29 00:00 |
17:22:52.31 |
+10:47:46.5 |
HIP 85087 |
9.51 |
| 2026-03-29 12:00 |
17:22:49.69 |
+10:48:32.9 |
HIP 85087 |
9.69 |
| 2026-03-30 00:00 |
17:22:47.00 |
+10:49:19.2 |
HIP 85087 |
9.99 |
| 2026-03-30 12:00 |
17:22:44.24 |
+10:50:05.4 |
HIP 85087 |
10.40 |
| 2026-03-31 00:00 |
17:22:41.40 |
+10:50:51.5 |
HIP 85087 |
10.90 |
| 2026-03-31 12:00 |
17:22:38.50 |
+10:51:37.4 |
HIP 85087 |
11.50 |
| 2026-04-01 00:00 |
17:22:35.53 |
+10:52:23.3 |
HIP 85087 |
12.17 |
| 2026-04-01 12:00 |
17:22:32.48 |
+10:53:09.0 |
HIP 85087 |
12.92 |
| 2026-04-02 00:00 |
17:22:29.37 |
+10:53:54.6 |
HIP 85087 |
13.72 |
| 2026-04-02 12:00 |
17:22:26.19 |
+10:54:40.1 |
HIP 85087 |
14.57 |
| 2026-04-03 00:00 |
17:22:22.94 |
+10:55:25.4 |
HIP 85087 |
15.47 |
| 2026-04-03 12:00 |
17:22:19.61 |
+10:56:10.6 |
HIP 84923 |
16.22 |
| 2026-04-04 00:00 |
17:22:16.22 |
+10:56:55.7 |
HIP 84923 |
15.16 |
| 2026-04-04 12:00 |
17:22:12.76 |
+10:57:40.6 |
HIP 84923 |
14.09 |
| 2026-04-05 00:00 |
17:22:09.23 |
+10:58:25.3 |
HIP 84923 |
13.01 |
| 2026-04-05 12:00 |
17:22:05.63 |
+10:59:09.9 |
HIP 84923 |
11.93 |
| 2026-04-06 00:00 |
17:22:01.97 |
+10:59:54.3 |
HIP 84923 |
10.85 |
| 2026-04-06 12:00 |
17:21:58.23 |
+11:00:38.5 |
HIP 84923 |
9.78 |
| 2026-04-07 00:00 |
17:21:54.43 |
+11:01:22.5 |
HIP 84923 |
8.72 |
| 2026-04-07 12:00 |
17:21:50.56 |
+11:02:06.4 |
HIP 84923 |
7.67 |
| 2026-04-08 00:00 |
17:21:46.62 |
+11:02:50.1 |
HIP 84923 |
6.66 |
| 2026-04-08 12:00 |
17:21:42.61 |
+11:03:33.5 |
HIP 84923 |
5.72 |
| 2026-04-09 00:00 |
17:21:38.54 |
+11:04:16.8 |
HIP 84923 |
4.88 |
| 2026-04-09 12:00 |
17:21:34.40 |
+11:04:59.9 |
HIP 84923 |
4.22 |
| 2026-04-10 00:00 |
17:21:30.19 |
+11:05:42.7 |
HIP 84923 |
3.84 |
| 2026-04-10 12:00 |
17:21:25.92 |
+11:06:25.3 |
HIP 84923 |
3.85 |
| 2026-04-11 00:00 |
17:21:21.58 |
+11:07:07.8 |
HIP 84923 |
4.25 |
| 2026-04-11 12:00 |
17:21:17.17 |
+11:07:49.9 |
HIP 84923 |
4.95 |
| 2026-04-12 00:00 |
17:21:12.70 |
+11:08:31.9 |
HIP 84923 |
5.86 |
| 2026-04-12 12:00 |
17:21:08.17 |
+11:09:13.6 |
HIP 84923 |
6.90 |
| 2026-04-13 00:00 |
17:21:03.56 |
+11:09:55.0 |
HIP 84923 |
8.02 |
| 2026-04-13 12:00 |
17:20:58.90 |
+11:10:36.3 |
HIP 84923 |
9.20 |
| 2026-04-14 00:00 |
17:20:54.17 |
+11:11:17.2 |
HIP 84923 |
10.42 |
| 2026-04-14 12:00 |
17:20:49.37 |
+11:11:57.9 |
HIP 84923 |
11.68 |
| 2026-04-15 00:00 |
17:20:44.51 |
+11:12:38.3 |
HIP 84923 |
12.97 |
| 2026-04-15 12:00 |
17:20:39.59 |
+11:13:18.5 |
HIP 84923 |
14.27 |
| 2026-04-16 00:00 |
17:20:34.60 |
+11:13:58.3 |
HIP 84923 |
15.60 |