| Parameter |
Value |
| Designation |
501P/Rankin |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2020-12-10T08:39:13.299840Z |
| Orbit solution date (soln_date, UTC) |
2025-07-31T16:54:57Z |
| Obs used |
98 |
| NEO |
Yes |
| M1 |
21.900 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2024-06-15T10:13:37.545600Z |
| Discovery magnitude (MPC) |
20.90 G |
| Discovery observatory (MPC) |
G96 · Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2022-05-24.0000000 |
| e |
0.69572032 |
| q (au) |
0.680308 |
| a (au) |
2.235797 |
| i (deg) |
10.104448 |
| Ω (om, deg) |
140.492867 |
| ω (w, deg) |
52.799047 |
| M (ma, deg) |
156.147750 |
Magnitude
Scatter + Global Linear
$$
M_a = (20.000 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
20.000 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.852 |
| k |
0.990 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2024-03-22 |
2024-07-29 |
-14.2233 |
+1.816 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
01:14:56.20 |
+00:22:43.0 |
HIP 5997 |
32.97 |
| 2026-03-26 12:00 |
01:15:25.65 |
+00:25:45.9 |
HIP 5997 |
26.45 |
| 2026-03-27 00:00 |
01:15:55.14 |
+00:28:48.6 |
HIP 5997 |
20.95 |
| 2026-03-27 12:00 |
01:16:24.66 |
+00:31:51.0 |
HIP 5997 |
17.46 |
| 2026-03-28 00:00 |
01:16:54.22 |
+00:34:53.3 |
HIP 5997 |
17.27 |
| 2026-03-28 12:00 |
01:17:23.82 |
+00:37:55.3 |
HIP 5997 |
20.47 |
| 2026-03-29 00:00 |
01:17:53.45 |
+00:40:57.2 |
HIP 6112 |
19.35 |
| 2026-03-29 12:00 |
01:18:23.12 |
+00:43:58.8 |
HIP 6112 |
14.32 |
| 2026-03-30 00:00 |
01:18:52.82 |
+00:47:00.2 |
HIP 6112 |
12.81 |
| 2026-03-30 12:00 |
01:19:22.56 |
+00:50:01.4 |
HIP 6112 |
15.87 |
| 2026-03-31 00:00 |
01:19:52.33 |
+00:53:02.3 |
HIP 6112 |
21.66 |
| 2026-03-31 12:00 |
01:20:22.13 |
+00:56:03.1 |
HIP 6112 |
28.56 |
| 2026-04-01 00:00 |
01:20:51.97 |
+00:59:03.6 |
HIP 6448 |
33.79 |
| 2026-04-01 12:00 |
01:21:21.84 |
+01:02:03.8 |
HIP 6448 |
29.37 |
| 2026-04-02 00:00 |
01:21:51.74 |
+01:05:03.8 |
HIP 6448 |
26.69 |
| 2026-04-02 12:00 |
01:22:21.67 |
+01:08:03.6 |
HIP 6448 |
26.30 |
| 2026-04-03 00:00 |
01:22:51.63 |
+01:11:03.1 |
HIP 6448 |
28.30 |
| 2026-04-03 12:00 |
01:23:21.63 |
+01:14:02.3 |
HIP 6432 |
31.59 |
| 2026-04-04 00:00 |
01:23:51.65 |
+01:17:01.4 |
HIP 6653 |
24.52 |
| 2026-04-04 12:00 |
01:24:21.70 |
+01:20:00.1 |
HIP 6653 |
16.47 |
| 2026-04-05 00:00 |
01:24:51.79 |
+01:22:58.6 |
HIP 6653 |
8.48 |
| 2026-04-05 12:00 |
01:25:21.90 |
+01:25:56.8 |
HIP 6653 |
1.77 |
| 2026-04-06 00:00 |
01:25:52.04 |
+01:28:54.7 |
HIP 6653 |
8.09 |
| 2026-04-06 12:00 |
01:26:22.21 |
+01:31:52.3 |
HIP 6750 |
16.00 |
| 2026-04-07 00:00 |
01:26:52.41 |
+01:34:49.7 |
HIP 6750 |
16.97 |
| 2026-04-07 12:00 |
01:27:22.63 |
+01:37:46.8 |
HIP 6750 |
21.24 |
| 2026-04-08 00:00 |
01:27:52.89 |
+01:40:43.6 |
HIP 6750 |
27.31 |
| 2026-04-08 12:00 |
01:28:23.16 |
+01:43:40.1 |
HIP 6777 |
30.59 |
| 2026-04-09 00:00 |
01:28:53.47 |
+01:46:36.3 |
HIP 6777 |
33.84 |
| 2026-04-09 12:00 |
01:29:23.80 |
+01:49:32.2 |
HIP 7025 |
32.70 |
| 2026-04-10 00:00 |
01:29:54.15 |
+01:52:27.7 |
HIP 7054 |
25.69 |
| 2026-04-10 12:00 |
01:30:24.53 |
+01:55:23.0 |
HIP 7054 |
19.39 |
| 2026-04-11 00:00 |
01:30:54.94 |
+01:58:17.9 |
HIP 7054 |
14.98 |
| 2026-04-11 12:00 |
01:31:25.36 |
+02:01:12.6 |
HIP 7054 |
14.33 |
| 2026-04-12 00:00 |
01:31:55.81 |
+02:04:06.9 |
HIP 7054 |
17.86 |
| 2026-04-12 12:00 |
01:32:26.29 |
+02:07:00.8 |
HIP 7270 |
22.99 |
| 2026-04-13 00:00 |
01:32:56.78 |
+02:09:54.4 |
HIP 7270 |
15.48 |
| 2026-04-13 12:00 |
01:33:27.30 |
+02:12:47.7 |
HIP 7270 |
9.13 |
| 2026-04-14 00:00 |
01:33:57.84 |
+02:15:40.6 |
HIP 7270 |
7.75 |
| 2026-04-14 12:00 |
01:34:28.39 |
+02:18:33.2 |
HIP 7312 |
9.74 |
| 2026-04-15 00:00 |
01:34:58.97 |
+02:21:25.4 |
HIP 7312 |
13.91 |
| 2026-04-15 12:00 |
01:35:29.57 |
+02:24:17.3 |
HIP 7312 |
20.63 |
| 2026-04-16 00:00 |
01:36:00.19 |
+02:27:08.8 |
HIP 7312 |
28.12 |