| Parameter |
Value |
| Designation |
C/2020 B3 (Rankin) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-10-19T21:22:57Z |
| Orbit solution date (soln_date, UTC) |
2022-07-06T03:12:24Z |
| Obs used |
185 |
| NEO |
- |
| M1 |
14.600 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-03-13.0000000 |
| e |
0.99826805 |
| q (au) |
3.344460 |
| a (au) |
1931.033136 |
| i (deg) |
20.701635 |
| Ω (om, deg) |
185.824602 |
| ω (w, deg) |
325.092308 |
| M (ma, deg) |
0.001685 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.046 + 2.957\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.046 |
| n |
2.957 |
| gf |
1.000 |
| gb |
-0.768 |
| 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) |
| 2026-05-12 00:00 |
18:41:49.61 |
-01:31:25.9 |
HIP 91743 |
16.50 |
| 2026-05-12 12:00 |
18:41:45.94 |
-01:31:00.6 |
HIP 91743 |
16.76 |
| 2026-05-13 00:00 |
18:41:42.22 |
-01:30:35.5 |
HIP 91743 |
17.08 |
| 2026-05-13 12:00 |
18:41:38.45 |
-01:30:10.6 |
HIP 91743 |
17.46 |
| 2026-05-14 00:00 |
18:41:34.63 |
-01:29:46.1 |
HIP 91743 |
17.91 |
| 2026-05-14 12:00 |
18:41:30.77 |
-01:29:21.8 |
HIP 91743 |
18.42 |
| 2026-05-15 00:00 |
18:41:26.87 |
-01:28:57.7 |
HIP 91743 |
18.99 |
| 2026-05-15 12:00 |
18:41:22.92 |
-01:28:34.0 |
HIP 91743 |
19.61 |
| 2026-05-16 00:00 |
18:41:18.92 |
-01:28:10.5 |
HIP 91743 |
20.27 |
| 2026-05-16 12:00 |
18:41:14.88 |
-01:27:47.3 |
HIP 91743 |
20.99 |
| 2026-05-17 00:00 |
18:41:10.79 |
-01:27:24.4 |
HIP 91743 |
21.74 |
| 2026-05-17 12:00 |
18:41:06.66 |
-01:27:01.7 |
HIP 91521 |
21.45 |
| 2026-05-18 00:00 |
18:41:02.49 |
-01:26:39.3 |
HIP 91521 |
20.35 |
| 2026-05-18 12:00 |
18:40:58.27 |
-01:26:17.2 |
HIP 91521 |
19.25 |
| 2026-05-19 00:00 |
18:40:54.01 |
-01:25:55.4 |
HIP 91521 |
18.14 |
| 2026-05-19 12:00 |
18:40:49.71 |
-01:25:33.9 |
HIP 91521 |
17.02 |
| 2026-05-20 00:00 |
18:40:45.37 |
-01:25:12.7 |
HIP 91521 |
15.90 |
| 2026-05-20 12:00 |
18:40:40.98 |
-01:24:51.8 |
HIP 91521 |
14.78 |
| 2026-05-21 00:00 |
18:40:36.56 |
-01:24:31.1 |
HIP 91521 |
13.66 |
| 2026-05-21 12:00 |
18:40:32.10 |
-01:24:10.8 |
HIP 91521 |
12.53 |
| 2026-05-22 00:00 |
18:40:27.59 |
-01:23:50.7 |
HIP 91521 |
11.41 |
| 2026-05-22 12:00 |
18:40:23.05 |
-01:23:30.9 |
HIP 91521 |
10.30 |
| 2026-05-23 00:00 |
18:40:18.47 |
-01:23:11.5 |
HIP 91521 |
9.20 |
| 2026-05-23 12:00 |
18:40:13.85 |
-01:22:52.3 |
HIP 91521 |
8.12 |
| 2026-05-24 00:00 |
18:40:09.19 |
-01:22:33.4 |
HIP 91521 |
7.07 |
| 2026-05-24 12:00 |
18:40:04.49 |
-01:22:14.9 |
HIP 91521 |
6.09 |
| 2026-05-25 00:00 |
18:39:59.76 |
-01:21:56.6 |
HIP 91521 |
5.20 |
| 2026-05-25 12:00 |
18:39:54.99 |
-01:21:38.7 |
HIP 91521 |
4.47 |
| 2026-05-26 00:00 |
18:39:50.19 |
-01:21:21.0 |
HIP 91521 |
4.01 |
| 2026-05-26 12:00 |
18:39:45.34 |
-01:21:03.7 |
HIP 91521 |
3.90 |
| 2026-05-27 00:00 |
18:39:40.47 |
-01:20:46.6 |
HIP 91521 |
4.19 |
| 2026-05-27 12:00 |
18:39:35.56 |
-01:20:29.9 |
HIP 91521 |
4.81 |
| 2026-05-28 00:00 |
18:39:30.61 |
-01:20:13.5 |
HIP 91521 |
5.65 |
| 2026-05-28 12:00 |
18:39:25.64 |
-01:19:57.4 |
HIP 91521 |
6.64 |
| 2026-05-29 00:00 |
18:39:20.62 |
-01:19:41.6 |
HIP 91521 |
7.72 |
| 2026-05-29 12:00 |
18:39:15.58 |
-01:19:26.1 |
HIP 91521 |
8.87 |
| 2026-05-30 00:00 |
18:39:10.50 |
-01:19:11.0 |
HIP 91521 |
10.06 |
| 2026-05-30 12:00 |
18:39:05.40 |
-01:18:56.1 |
HIP 91521 |
11.28 |
| 2026-05-31 00:00 |
18:39:00.26 |
-01:18:41.6 |
HIP 91521 |
12.52 |
| 2026-05-31 12:00 |
18:38:55.08 |
-01:18:27.4 |
HIP 91452 |
12.86 |
| 2026-06-01 00:00 |
18:38:49.88 |
-01:18:13.5 |
HIP 91452 |
13.02 |
| 2026-06-01 12:00 |
18:38:44.65 |
-01:18:00.0 |
HIP 91384 |
12.92 |
| 2026-06-02 00:00 |
18:38:39.39 |
-01:17:46.7 |
HIP 91384 |
12.12 |