| Parameter |
Value |
| Designation |
C/2021 V1 (Rankin) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2022-04-30T08:37:20.375040Z |
| Orbit solution date (soln_date, UTC) |
2022-02-14T01:12:42Z |
| Obs used |
67 |
| NEO |
- |
| M1 |
15.900 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-11-05T03:51:31.478400Z |
| Discovery magnitude (MPC) |
20.97 G |
| Discovery observatory (MPC) |
G96 · Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-11-16.0000000 |
| e |
0.99556441 |
| q (au) |
3.013528 |
| a (au) |
679.397411 |
| i (deg) |
71.440704 |
| Ω (om, deg) |
207.653208 |
| ω (w, deg) |
195.103041 |
| M (ma, deg) |
359.990797 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.742 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.742 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.803 |
| 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) |
| 2026-03-26 00:00 |
11:01:40.57 |
-45:27:03.2 |
HIP 54010 |
13.25 |
| 2026-03-26 12:00 |
11:01:30.12 |
-45:25:22.0 |
HIP 54010 |
15.14 |
| 2026-03-27 00:00 |
11:01:19.73 |
-45:23:39.9 |
HIP 54010 |
17.18 |
| 2026-03-27 12:00 |
11:01:09.40 |
-45:21:56.9 |
HIP 54010 |
19.32 |
| 2026-03-28 00:00 |
11:00:59.13 |
-45:20:13.0 |
HIP 54010 |
21.53 |
| 2026-03-28 12:00 |
11:00:48.93 |
-45:18:28.2 |
HIP 54010 |
23.80 |
| 2026-03-29 00:00 |
11:00:38.79 |
-45:16:42.6 |
HIP 53782 |
22.45 |
| 2026-03-29 12:00 |
11:00:28.72 |
-45:14:56.1 |
HIP 53782 |
20.42 |
| 2026-03-30 00:00 |
11:00:18.71 |
-45:13:08.7 |
HIP 53782 |
18.51 |
| 2026-03-30 12:00 |
11:00:08.77 |
-45:11:20.5 |
HIP 53782 |
16.74 |
| 2026-03-31 00:00 |
10:59:58.90 |
-45:09:31.4 |
HIP 53782 |
15.17 |
| 2026-03-31 12:00 |
10:59:49.10 |
-45:07:41.6 |
HIP 53782 |
13.86 |
| 2026-04-01 00:00 |
10:59:39.37 |
-45:05:50.9 |
HIP 53782 |
12.90 |
| 2026-04-01 12:00 |
10:59:29.71 |
-45:03:59.4 |
HIP 53782 |
12.37 |
| 2026-04-02 00:00 |
10:59:20.13 |
-45:02:07.1 |
HIP 53638 |
11.67 |
| 2026-04-02 12:00 |
10:59:10.61 |
-45:00:14.1 |
HIP 53638 |
9.29 |
| 2026-04-03 00:00 |
10:59:01.17 |
-44:58:20.2 |
HIP 53638 |
7.01 |
| 2026-04-03 12:00 |
10:58:51.81 |
-44:56:25.6 |
HIP 53638 |
5.00 |
| 2026-04-04 00:00 |
10:58:42.52 |
-44:54:30.3 |
HIP 53638 |
3.69 |
| 2026-04-04 12:00 |
10:58:33.31 |
-44:52:34.2 |
HIP 53638 |
3.90 |
| 2026-04-05 00:00 |
10:58:24.17 |
-44:50:37.3 |
HIP 53638 |
5.45 |
| 2026-04-05 12:00 |
10:58:15.12 |
-44:48:39.8 |
HIP 53638 |
7.56 |
| 2026-04-06 00:00 |
10:58:06.14 |
-44:46:41.5 |
HIP 53638 |
9.88 |
| 2026-04-06 12:00 |
10:57:57.25 |
-44:44:42.6 |
HIP 53542 |
9.03 |
| 2026-04-07 00:00 |
10:57:48.43 |
-44:42:42.9 |
HIP 53542 |
8.83 |
| 2026-04-07 12:00 |
10:57:39.70 |
-44:40:42.6 |
HIP 53542 |
9.35 |
| 2026-04-08 00:00 |
10:57:31.05 |
-44:38:41.6 |
HIP 53542 |
10.50 |
| 2026-04-08 12:00 |
10:57:22.49 |
-44:36:39.9 |
HIP 53542 |
12.08 |
| 2026-04-09 00:00 |
10:57:14.00 |
-44:34:37.6 |
HIP 53542 |
13.96 |
| 2026-04-09 12:00 |
10:57:05.61 |
-44:32:34.7 |
HIP 53542 |
16.04 |
| 2026-04-10 00:00 |
10:56:57.30 |
-44:30:31.1 |
HIP 53542 |
18.23 |
| 2026-04-10 12:00 |
10:56:49.07 |
-44:28:26.9 |
HIP 53418 |
18.70 |
| 2026-04-11 00:00 |
10:56:40.94 |
-44:26:22.1 |
HIP 53418 |
19.38 |
| 2026-04-11 12:00 |
10:56:32.89 |
-44:24:16.8 |
HIP 53418 |
20.37 |
| 2026-04-12 00:00 |
10:56:24.93 |
-44:22:10.8 |
HIP 53418 |
21.63 |
| 2026-04-12 12:00 |
10:56:17.06 |
-44:20:04.3 |
HIP 53418 |
23.11 |
| 2026-04-13 00:00 |
10:56:09.29 |
-44:17:57.2 |
HIP 53418 |
24.77 |
| 2026-04-13 12:00 |
10:56:01.60 |
-44:15:49.6 |
HIP 53418 |
26.59 |
| 2026-04-14 00:00 |
10:55:54.00 |
-44:13:41.4 |
HIP 53418 |
28.52 |
| 2026-04-14 12:00 |
10:55:46.50 |
-44:11:32.7 |
HIP 53244 |
28.39 |
| 2026-04-15 00:00 |
10:55:39.09 |
-44:09:23.5 |
HIP 53244 |
28.33 |
| 2026-04-15 12:00 |
10:55:31.78 |
-44:07:13.8 |
HIP 53547 |
27.91 |
| 2026-04-16 00:00 |
10:55:24.56 |
-44:05:03.7 |
HIP 53547 |
27.30 |