| Parameter |
Value |
| Designation |
P/2020 W1 (Rankin) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2020-04-04T04:06:18.002880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:34:15Z |
| Obs used |
89 |
| NEO |
- |
| M1 |
10.400 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-11-16T08:16:49.900800Z |
| Discovery magnitude (MPC) |
20.90 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-11-08.0000000 |
| e |
0.26491783 |
| q (au) |
5.287627 |
| a (au) |
7.193246 |
| i (deg) |
10.792086 |
| Ω (om, deg) |
124.257217 |
| ω (w, deg) |
264.771285 |
| M (ma, deg) |
11.128390 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.338 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.338 |
| n |
2.000 |
| 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) |
| 2026-09-20 00:00 |
11:40:08.67 |
+09:49:58.9 |
HIP 56930 |
19.34 |
| 2026-09-20 12:00 |
11:40:23.95 |
+09:48:31.4 |
HIP 56930 |
17.87 |
| 2026-09-21 00:00 |
11:40:39.22 |
+09:47:04.1 |
HIP 57040 |
15.39 |
| 2026-09-21 12:00 |
11:40:54.49 |
+09:45:37.0 |
HIP 57040 |
11.43 |
| 2026-09-22 00:00 |
11:41:09.75 |
+09:44:10.2 |
HIP 57040 |
7.56 |
| 2026-09-22 12:00 |
11:41:25.00 |
+09:42:43.5 |
HIP 57040 |
4.00 |
| 2026-09-23 00:00 |
11:41:40.25 |
+09:41:17.0 |
HIP 57040 |
2.71 |
| 2026-09-23 12:00 |
11:41:55.48 |
+09:39:50.7 |
HIP 57040 |
5.57 |
| 2026-09-24 00:00 |
11:42:10.71 |
+09:38:24.7 |
HIP 57040 |
9.32 |
| 2026-09-24 12:00 |
11:42:25.93 |
+09:36:58.8 |
HIP 57040 |
13.23 |
| 2026-09-25 00:00 |
11:42:41.14 |
+09:35:33.2 |
HIP 57040 |
17.18 |
| 2026-09-25 12:00 |
11:42:56.34 |
+09:34:07.8 |
HIP 57040 |
21.15 |
| 2026-09-26 00:00 |
11:43:11.52 |
+09:32:42.7 |
HIP 57040 |
25.13 |
| 2026-09-26 12:00 |
11:43:26.70 |
+09:31:17.7 |
HIP 57040 |
29.11 |
| 2026-09-27 00:00 |
11:43:41.87 |
+09:29:53.0 |
HIP 57040 |
33.10 |
| 2026-09-27 12:00 |
11:43:57.02 |
+09:28:28.6 |
HIP 57040 |
37.08 |
| 2026-09-28 00:00 |
11:44:12.16 |
+09:27:04.3 |
HIP 57425 |
39.27 |
| 2026-09-28 12:00 |
11:44:27.29 |
+09:25:40.3 |
HIP 57425 |
35.43 |
| 2026-09-29 00:00 |
11:44:42.40 |
+09:24:16.6 |
HIP 57425 |
31.62 |
| 2026-09-29 12:00 |
11:44:57.50 |
+09:22:53.1 |
HIP 57425 |
27.88 |
| 2026-09-30 00:00 |
11:45:12.59 |
+09:21:29.9 |
HIP 57425 |
24.21 |
| 2026-09-30 12:00 |
11:45:27.66 |
+09:20:06.9 |
HIP 57425 |
20.65 |
| 2026-10-01 00:00 |
11:45:42.72 |
+09:18:44.2 |
HIP 57425 |
17.29 |
| 2026-10-01 12:00 |
11:45:57.76 |
+09:17:21.8 |
HIP 57425 |
14.24 |
| 2026-10-02 00:00 |
11:46:12.78 |
+09:15:59.6 |
HIP 57425 |
11.76 |
| 2026-10-02 12:00 |
11:46:27.79 |
+09:14:37.7 |
HIP 57425 |
10.24 |
| 2026-10-03 00:00 |
11:46:42.78 |
+09:13:16.0 |
HIP 57425 |
10.14 |
| 2026-10-03 12:00 |
11:46:57.75 |
+09:11:54.7 |
HIP 57425 |
11.48 |
| 2026-10-04 00:00 |
11:47:12.70 |
+09:10:33.6 |
HIP 57425 |
13.85 |
| 2026-10-04 12:00 |
11:47:27.64 |
+09:09:12.8 |
HIP 57425 |
16.81 |
| 2026-10-05 00:00 |
11:47:42.55 |
+09:07:52.3 |
HIP 57425 |
20.10 |
| 2026-10-05 12:00 |
11:47:57.45 |
+09:06:32.1 |
HIP 57425 |
23.57 |
| 2026-10-06 00:00 |
11:48:12.32 |
+09:05:12.2 |
HIP 57425 |
27.17 |
| 2026-10-06 12:00 |
11:48:27.18 |
+09:03:52.7 |
HIP 57501 |
30.79 |
| 2026-10-07 00:00 |
11:48:42.01 |
+09:02:33.4 |
HIP 57501 |
34.14 |
| 2026-10-07 12:00 |
11:48:56.81 |
+09:01:14.4 |
HIP 57501 |
37.59 |
| 2026-10-08 00:00 |
11:49:11.60 |
+08:59:55.8 |
HIP 57755 |
38.04 |
| 2026-10-08 12:00 |
11:49:26.36 |
+08:58:37.5 |
HIP 57755 |
37.18 |
| 2026-10-09 00:00 |
11:49:41.10 |
+08:57:19.5 |
HIP 57856 |
34.39 |
| 2026-10-09 12:00 |
11:49:55.81 |
+08:56:01.8 |
HIP 57856 |
30.56 |
| 2026-10-10 00:00 |
11:50:10.50 |
+08:54:44.5 |
HIP 57856 |
26.74 |
| 2026-10-10 12:00 |
11:50:25.16 |
+08:53:27.5 |
HIP 57856 |
22.94 |
| 2026-10-11 00:00 |
11:50:39.79 |
+08:52:10.8 |
HIP 57856 |
19.17 |