| Parameter |
Value |
| Designation |
P/2021 R5 (Rankin) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2022-01-11T23:34:59.966400Z |
| Orbit solution date (soln_date, UTC) |
2024-04-29T13:12:24Z |
| Obs used |
251 |
| NEO |
- |
| M1 |
7.200 |
| K1 |
18.750 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2021-09-09T06:52:28.416000Z |
| Discovery magnitude (MPC) |
19.34 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-10-17.0000000 |
| e |
0.30753521 |
| q (au) |
3.322719 |
| a (au) |
4.798394 |
| i (deg) |
7.852203 |
| Ω (om, deg) |
219.963779 |
| ω (w, deg) |
167.335702 |
| M (ma, deg) |
351.843709 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.399 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.399 |
| n |
6.000 |
| gf |
0.975 |
| gb |
-0.934 |
| k |
1.000 |
| δ90 |
9.557 |
| 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 |
12:47:34.04 |
-08:01:33.7 |
HIP 62371 |
16.11 |
| 2026-09-20 12:00 |
12:47:54.19 |
-08:03:25.7 |
HIP 62371 |
20.61 |
| 2026-09-21 00:00 |
12:48:14.36 |
-08:05:17.9 |
HIP 62371 |
25.44 |
| 2026-09-21 12:00 |
12:48:34.56 |
-08:07:10.3 |
HIP 62371 |
30.45 |
| 2026-09-22 00:00 |
12:48:54.78 |
-08:09:02.8 |
HIP 62371 |
35.56 |
| 2026-09-22 12:00 |
12:49:15.03 |
-08:10:55.5 |
HIP 62636 |
35.26 |
| 2026-09-23 00:00 |
12:49:35.30 |
-08:12:48.4 |
HIP 62636 |
35.66 |
| 2026-09-23 12:00 |
12:49:55.58 |
-08:14:41.5 |
HIP 62795 |
35.91 |
| 2026-09-24 00:00 |
12:50:15.89 |
-08:16:34.7 |
HIP 62795 |
30.59 |
| 2026-09-24 12:00 |
12:50:36.22 |
-08:18:28.0 |
HIP 62795 |
25.29 |
| 2026-09-25 00:00 |
12:50:56.57 |
-08:20:21.5 |
HIP 62795 |
20.02 |
| 2026-09-25 12:00 |
12:51:16.94 |
-08:22:15.1 |
HIP 62795 |
14.82 |
| 2026-09-26 00:00 |
12:51:37.33 |
-08:24:08.9 |
HIP 62795 |
9.82 |
| 2026-09-26 12:00 |
12:51:57.74 |
-08:26:02.9 |
HIP 62795 |
5.59 |
| 2026-09-27 00:00 |
12:52:18.16 |
-08:27:56.9 |
HIP 62795 |
4.92 |
| 2026-09-27 12:00 |
12:52:38.60 |
-08:29:51.1 |
HIP 62795 |
8.68 |
| 2026-09-28 00:00 |
12:52:59.06 |
-08:31:45.4 |
HIP 62844 |
11.28 |
| 2026-09-28 12:00 |
12:53:19.54 |
-08:33:39.9 |
HIP 62844 |
12.22 |
| 2026-09-29 00:00 |
12:53:40.03 |
-08:35:34.4 |
HIP 62844 |
15.17 |
| 2026-09-29 12:00 |
12:54:00.53 |
-08:37:29.1 |
HIP 62844 |
19.22 |
| 2026-09-30 00:00 |
12:54:21.06 |
-08:39:23.9 |
HIP 63088 |
18.67 |
| 2026-09-30 12:00 |
12:54:41.59 |
-08:41:18.8 |
HIP 63088 |
13.32 |
| 2026-10-01 00:00 |
12:55:02.14 |
-08:43:13.8 |
HIP 63088 |
8.07 |
| 2026-10-01 12:00 |
12:55:22.71 |
-08:45:08.9 |
HIP 63088 |
3.44 |
| 2026-10-02 00:00 |
12:55:43.29 |
-08:47:04.2 |
HIP 63088 |
4.19 |
| 2026-10-02 12:00 |
12:56:03.88 |
-08:48:59.5 |
HIP 63088 |
9.08 |
| 2026-10-03 00:00 |
12:56:24.48 |
-08:50:54.9 |
HIP 63225 |
13.98 |
| 2026-10-03 12:00 |
12:56:45.09 |
-08:52:50.3 |
HIP 63225 |
8.57 |
| 2026-10-04 00:00 |
12:57:05.72 |
-08:54:45.9 |
HIP 63225 |
3.29 |
| 2026-10-04 12:00 |
12:57:26.35 |
-08:56:41.5 |
HIP 63225 |
2.73 |
| 2026-10-05 00:00 |
12:57:47.00 |
-08:58:37.3 |
HIP 63225 |
7.97 |
| 2026-10-05 12:00 |
12:58:07.65 |
-09:00:33.1 |
HIP 63225 |
13.38 |
| 2026-10-06 00:00 |
12:58:28.32 |
-09:02:28.9 |
HIP 63225 |
18.82 |
| 2026-10-06 12:00 |
12:58:48.99 |
-09:04:24.8 |
HIP 63362 |
20.26 |
| 2026-10-07 00:00 |
12:59:09.67 |
-09:06:20.8 |
HIP 63486 |
19.72 |
| 2026-10-07 12:00 |
12:59:30.36 |
-09:08:16.8 |
HIP 63486 |
14.78 |
| 2026-10-08 00:00 |
12:59:51.05 |
-09:10:12.9 |
HIP 63486 |
10.39 |
| 2026-10-08 12:00 |
13:00:11.75 |
-09:12:09.0 |
HIP 63486 |
7.54 |
| 2026-10-09 00:00 |
13:00:32.45 |
-09:14:05.1 |
HIP 63486 |
8.10 |
| 2026-10-09 12:00 |
13:00:53.16 |
-09:16:01.3 |
HIP 63486 |
11.58 |
| 2026-10-10 00:00 |
13:01:13.87 |
-09:17:57.5 |
HIP 63486 |
16.19 |
| 2026-10-10 12:00 |
13:01:34.59 |
-09:19:53.8 |
HIP 63573 |
18.62 |
| 2026-10-11 00:00 |
13:01:55.30 |
-09:21:50.0 |
HIP 63573 |
17.00 |