| Parameter |
Value |
| Designation |
P/2024 S2 (Rankin) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2024-09-16T12:34:51.294720Z |
| Orbit solution date (soln_date, UTC) |
2025-01-13T08:43:47Z |
| Obs used |
154 |
| NEO |
- |
| M1 |
14.700 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2024-09-30T10:08:03.696000Z |
| Discovery magnitude (MPC) |
17.60 G |
| Discovery observatory (MPC) |
V11 · Saguaro Observatory, Tucson |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2024-10-04.0000000 |
| e |
0.59215299 |
| q (au) |
2.047742 |
| a (au) |
5.020858 |
| i (deg) |
7.523796 |
| Ω (om, deg) |
8.352672 |
| ω (w, deg) |
49.240931 |
| M (ma, deg) |
1.530996 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.271 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.271 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.998 |
| 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 |
12:28:45.22 |
-03:18:23.0 |
HIP 60956 |
14.48 |
| 2026-09-20 12:00 |
12:29:07.30 |
-03:20:58.0 |
HIP 60956 |
8.96 |
| 2026-09-21 00:00 |
12:29:29.38 |
-03:23:32.9 |
HIP 60956 |
4.98 |
| 2026-09-21 12:00 |
12:29:51.47 |
-03:26:07.8 |
HIP 60956 |
6.59 |
| 2026-09-22 00:00 |
12:30:13.56 |
-03:28:42.7 |
HIP 60956 |
11.67 |
| 2026-09-22 12:00 |
12:30:35.65 |
-03:31:17.6 |
HIP 60956 |
17.41 |
| 2026-09-23 00:00 |
12:30:57.75 |
-03:33:52.4 |
HIP 61139 |
14.12 |
| 2026-09-23 12:00 |
12:31:19.84 |
-03:36:27.2 |
HIP 61139 |
8.35 |
| 2026-09-24 00:00 |
12:31:41.94 |
-03:39:01.9 |
HIP 61139 |
3.75 |
| 2026-09-24 12:00 |
12:32:04.04 |
-03:41:36.6 |
HIP 61139 |
5.71 |
| 2026-09-25 00:00 |
12:32:26.14 |
-03:44:11.2 |
HIP 61139 |
11.19 |
| 2026-09-25 12:00 |
12:32:48.23 |
-03:46:45.8 |
HIP 61139 |
17.08 |
| 2026-09-26 00:00 |
12:33:10.33 |
-03:49:20.3 |
HIP 61349 |
16.83 |
| 2026-09-26 12:00 |
12:33:32.42 |
-03:51:54.8 |
HIP 61349 |
13.37 |
| 2026-09-27 00:00 |
12:33:54.52 |
-03:54:29.2 |
HIP 61349 |
12.16 |
| 2026-09-27 12:00 |
12:34:16.61 |
-03:57:03.6 |
HIP 61349 |
13.82 |
| 2026-09-28 00:00 |
12:34:38.70 |
-03:59:37.8 |
HIP 61438 |
11.37 |
| 2026-09-28 12:00 |
12:35:00.78 |
-04:02:12.0 |
HIP 61438 |
5.31 |
| 2026-09-29 00:00 |
12:35:22.87 |
-04:04:46.2 |
HIP 61438 |
0.97 |
| 2026-09-29 12:00 |
12:35:44.94 |
-04:07:20.2 |
HIP 61438 |
6.89 |
| 2026-09-30 00:00 |
12:36:07.02 |
-04:09:54.2 |
HIP 61438 |
12.96 |
| 2026-09-30 12:00 |
12:36:29.08 |
-04:12:28.1 |
HIP 61438 |
19.02 |
| 2026-10-01 00:00 |
12:36:51.15 |
-04:15:01.9 |
HIP 61581 |
24.45 |
| 2026-10-01 12:00 |
12:37:13.20 |
-04:17:35.6 |
HIP 61581 |
21.49 |
| 2026-10-02 00:00 |
12:37:35.25 |
-04:20:09.2 |
HIP 61685 |
17.13 |
| 2026-10-02 12:00 |
12:37:57.29 |
-04:22:42.7 |
HIP 61685 |
11.49 |
| 2026-10-03 00:00 |
12:38:19.33 |
-04:25:16.1 |
HIP 61685 |
6.64 |
| 2026-10-03 12:00 |
12:38:41.35 |
-04:27:49.5 |
HIP 61685 |
5.43 |
| 2026-10-04 00:00 |
12:39:03.37 |
-04:30:22.7 |
HIP 61685 |
9.40 |
| 2026-10-04 12:00 |
12:39:25.38 |
-04:32:55.8 |
HIP 61685 |
14.84 |
| 2026-10-05 00:00 |
12:39:47.38 |
-04:35:28.7 |
HIP 61685 |
20.62 |
| 2026-10-05 12:00 |
12:40:09.37 |
-04:38:01.6 |
HIP 61894 |
14.85 |
| 2026-10-06 00:00 |
12:40:31.34 |
-04:40:34.3 |
HIP 61894 |
8.85 |
| 2026-10-06 12:00 |
12:40:53.31 |
-04:43:06.9 |
HIP 61894 |
2.99 |
| 2026-10-07 00:00 |
12:41:15.26 |
-04:45:39.4 |
HIP 61894 |
3.53 |
| 2026-10-07 12:00 |
12:41:37.20 |
-04:48:11.8 |
HIP 61894 |
9.42 |
| 2026-10-08 00:00 |
12:41:59.12 |
-04:50:43.9 |
HIP 61894 |
15.41 |
| 2026-10-08 12:00 |
12:42:21.04 |
-04:53:16.0 |
HIP 61971 |
20.68 |
| 2026-10-09 00:00 |
12:42:42.93 |
-04:55:47.9 |
HIP 61971 |
20.52 |
| 2026-10-09 12:00 |
12:43:04.81 |
-04:58:19.6 |
HIP 61971 |
22.05 |
| 2026-10-10 00:00 |
12:43:26.68 |
-05:00:51.2 |
HIP 61971 |
24.97 |
| 2026-10-10 12:00 |
12:43:48.52 |
-05:03:22.7 |
HIP 62250 |
24.73 |
| 2026-10-11 00:00 |
12:44:10.35 |
-05:05:53.9 |
HIP 62250 |
19.00 |