C/2020 R6 (Rankin)
| Parameter |
Value |
| Designation |
C/2020 R6 (Rankin) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-09-09T23:50:03.036480Z |
| Orbit solution date (soln_date, UTC) |
2021-12-17T03:12:50Z |
| Obs used |
56 |
| NEO |
- |
| M1 |
14.800 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-09-15T10:08:55.968000Z |
| Discovery magnitude (MPC) |
20.20 G |
| Discovery observatory (MPC) |
G96 · Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-08-21.0000000 |
| e |
0.99221066 |
| q (au) |
3.129707 |
| a (au) |
401.793824 |
| i (deg) |
82.814904 |
| Ω (om, deg) |
12.177097 |
| ω (w, deg) |
272.005055 |
| M (ma, deg) |
0.042343 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.617 + 2.630\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.617 |
| n |
2.630 |
| gf |
1.000 |
| gb |
-0.821 |
| k |
0.800 |
| δ90 |
9.998 |
| 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) |
| 2026-02-03 00:00 |
23:35:57.01 |
+41:38:04.8 |
HIP 116443 |
20.11 |
| 2026-02-03 12:00 |
23:36:03.18 |
+41:37:56.1 |
HIP 116443 |
20.42 |
| 2026-02-04 00:00 |
23:36:09.39 |
+41:37:48.0 |
HIP 116443 |
20.79 |
| 2026-02-04 12:00 |
23:36:15.64 |
+41:37:40.6 |
HIP 116443 |
21.21 |
| 2026-02-05 00:00 |
23:36:21.92 |
+41:37:33.8 |
HIP 116443 |
21.67 |
| 2026-02-05 12:00 |
23:36:28.25 |
+41:37:27.7 |
HIP 116443 |
22.18 |
| 2026-02-06 00:00 |
23:36:34.62 |
+41:37:22.2 |
HIP 116443 |
22.73 |
| 2026-02-06 12:00 |
23:36:41.03 |
+41:37:17.4 |
HIP 116669 |
21.66 |
| 2026-02-07 00:00 |
23:36:47.47 |
+41:37:13.2 |
HIP 116669 |
20.46 |
| 2026-02-07 12:00 |
23:36:53.95 |
+41:37:09.6 |
HIP 116669 |
19.25 |
| 2026-02-08 00:00 |
23:37:00.47 |
+41:37:06.7 |
HIP 116669 |
18.03 |
| 2026-02-08 12:00 |
23:37:07.03 |
+41:37:04.5 |
HIP 116669 |
16.81 |
| 2026-02-09 00:00 |
23:37:13.62 |
+41:37:02.9 |
HIP 116669 |
15.57 |
| 2026-02-09 12:00 |
23:37:20.25 |
+41:37:02.0 |
HIP 116669 |
14.34 |
| 2026-02-10 00:00 |
23:37:26.91 |
+41:37:01.7 |
HIP 116669 |
13.09 |
| 2026-02-10 12:00 |
23:37:33.61 |
+41:37:02.1 |
HIP 116669 |
11.84 |
| 2026-02-11 00:00 |
23:37:40.34 |
+41:37:03.1 |
HIP 116669 |
10.58 |
| 2026-02-11 12:00 |
23:37:47.10 |
+41:37:04.7 |
HIP 116669 |
9.32 |
| 2026-02-12 00:00 |
23:37:53.90 |
+41:37:07.1 |
HIP 116669 |
8.05 |
| 2026-02-12 12:00 |
23:38:00.74 |
+41:37:10.0 |
HIP 116669 |
6.77 |
| 2026-02-13 00:00 |
23:38:07.60 |
+41:37:13.6 |
HIP 116669 |
5.49 |
| 2026-02-13 12:00 |
23:38:14.50 |
+41:37:17.9 |
HIP 116669 |
4.19 |
| 2026-02-14 00:00 |
23:38:21.42 |
+41:37:22.8 |
HIP 116669 |
2.90 |
| 2026-02-14 12:00 |
23:38:28.38 |
+41:37:28.4 |
HIP 116669 |
1.60 |
| 2026-02-15 00:00 |
23:38:35.37 |
+41:37:34.6 |
HIP 116669 |
0.32 |
| 2026-02-15 12:00 |
23:38:42.38 |
+41:37:41.5 |
HIP 116669 |
1.05 |
| 2026-02-16 00:00 |
23:38:49.43 |
+41:37:49.0 |
HIP 116669 |
2.37 |
| 2026-02-16 12:00 |
23:38:56.51 |
+41:37:57.1 |
HIP 116669 |
3.69 |
| 2026-02-17 00:00 |
23:39:03.61 |
+41:38:05.9 |
HIP 116669 |
5.03 |
| 2026-02-17 12:00 |
23:39:10.74 |
+41:38:15.4 |
HIP 116669 |
6.37 |
| 2026-02-18 00:00 |
23:39:17.90 |
+41:38:25.5 |
HIP 116669 |
7.72 |
| 2026-02-18 12:00 |
23:39:25.08 |
+41:38:36.2 |
HIP 116669 |
9.07 |
| 2026-02-19 00:00 |
23:39:32.29 |
+41:38:47.6 |
HIP 116669 |
10.43 |
| 2026-02-19 12:00 |
23:39:39.52 |
+41:38:59.6 |
HIP 116669 |
11.80 |
| 2026-02-20 00:00 |
23:39:46.78 |
+41:39:12.3 |
HIP 116669 |
13.17 |
| 2026-02-20 12:00 |
23:39:54.07 |
+41:39:25.6 |
HIP 116669 |
14.55 |
| 2026-02-21 00:00 |
23:40:01.37 |
+41:39:39.5 |
HIP 116669 |
15.93 |
| 2026-02-21 12:00 |
23:40:08.70 |
+41:39:54.1 |
HIP 116847 |
15.25 |
| 2026-02-22 00:00 |
23:40:16.06 |
+41:40:09.3 |
HIP 116847 |
14.15 |
| 2026-02-22 12:00 |
23:40:23.43 |
+41:40:25.2 |
HIP 116847 |
13.09 |
| 2026-02-23 00:00 |
23:40:30.82 |
+41:40:41.6 |
HIP 116847 |
12.10 |
| 2026-02-23 12:00 |
23:40:38.24 |
+41:40:58.7 |
HIP 116847 |
11.19 |
| 2026-02-24 00:00 |
23:40:45.68 |
+41:41:16.5 |
HIP 116847 |
10.37 |