| 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 · University of Arizona 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 |
-14.2235 |
+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) |
| 2026-06-01 00:00 |
02:23:07.01 |
+06:14:01.0 |
HIP 11132 |
14.24 |
| 2026-06-01 12:00 |
02:23:37.08 |
+06:15:59.4 |
HIP 11132 |
17.01 |
| 2026-06-02 00:00 |
02:24:07.11 |
+06:17:57.1 |
HIP 11151 |
20.76 |
| 2026-06-02 12:00 |
02:24:37.12 |
+06:19:54.0 |
HIP 11151 |
23.87 |
| 2026-06-03 00:00 |
02:25:07.09 |
+06:21:50.1 |
HIP 11360 |
17.70 |
| 2026-06-03 12:00 |
02:25:37.02 |
+06:23:45.4 |
HIP 11360 |
11.54 |
| 2026-06-04 00:00 |
02:26:06.93 |
+06:25:40.0 |
HIP 11360 |
8.43 |
| 2026-06-04 12:00 |
02:26:36.80 |
+06:27:33.8 |
HIP 11360 |
11.24 |
| 2026-06-05 00:00 |
02:27:06.63 |
+06:29:26.8 |
HIP 11411 |
15.87 |
| 2026-06-05 12:00 |
02:27:36.43 |
+06:31:19.1 |
HIP 11411 |
19.53 |
| 2026-06-06 00:00 |
02:28:06.19 |
+06:33:10.5 |
HIP 11563 |
20.29 |
| 2026-06-06 12:00 |
02:28:35.91 |
+06:35:01.1 |
HIP 11563 |
14.88 |
| 2026-06-07 00:00 |
02:29:05.60 |
+06:36:51.0 |
HIP 11563 |
12.14 |
| 2026-06-07 12:00 |
02:29:35.24 |
+06:38:40.0 |
HIP 11563 |
13.74 |
| 2026-06-08 00:00 |
02:30:04.85 |
+06:40:28.2 |
HIP 11563 |
18.57 |
| 2026-06-08 12:00 |
02:30:34.42 |
+06:42:15.6 |
HIP 11798 |
24.28 |
| 2026-06-09 00:00 |
02:31:03.94 |
+06:44:02.2 |
HIP 11798 |
16.97 |
| 2026-06-09 12:00 |
02:31:33.43 |
+06:45:48.0 |
HIP 11798 |
10.01 |
| 2026-06-10 00:00 |
02:32:02.87 |
+06:47:32.9 |
HIP 11798 |
5.06 |
| 2026-06-10 12:00 |
02:32:32.27 |
+06:49:17.0 |
HIP 11798 |
7.99 |
| 2026-06-11 00:00 |
02:33:01.62 |
+06:51:00.2 |
HIP 11854 |
6.39 |
| 2026-06-11 12:00 |
02:33:30.93 |
+06:52:42.6 |
HIP 11854 |
9.03 |
| 2026-06-12 00:00 |
02:34:00.20 |
+06:54:24.2 |
HIP 11854 |
15.29 |
| 2026-06-12 12:00 |
02:34:29.41 |
+06:56:04.8 |
HIP 11854 |
22.28 |
| 2026-06-13 00:00 |
02:34:58.58 |
+06:57:44.7 |
HIP 12114 |
16.87 |
| 2026-06-13 12:00 |
02:35:27.70 |
+06:59:23.6 |
HIP 12114 |
11.01 |
| 2026-06-14 00:00 |
02:35:56.77 |
+07:01:01.7 |
HIP 12114 |
8.22 |
| 2026-06-14 12:00 |
02:36:25.79 |
+07:02:38.9 |
HIP 12114 |
11.08 |
| 2026-06-15 00:00 |
02:36:54.76 |
+07:04:15.3 |
HIP 12114 |
16.92 |
| 2026-06-15 12:00 |
02:37:23.67 |
+07:05:50.7 |
HIP 12323 |
21.17 |
| 2026-06-16 00:00 |
02:37:52.53 |
+07:07:25.2 |
HIP 12323 |
16.01 |
| 2026-06-16 12:00 |
02:38:21.34 |
+07:08:58.9 |
HIP 12323 |
13.10 |
| 2026-06-17 00:00 |
02:38:50.09 |
+07:10:31.6 |
HIP 12323 |
13.91 |
| 2026-06-17 12:00 |
02:39:18.78 |
+07:12:03.5 |
HIP 12323 |
17.93 |
| 2026-06-18 00:00 |
02:39:47.42 |
+07:13:34.4 |
HIP 12323 |
23.54 |
| 2026-06-18 12:00 |
02:40:16.00 |
+07:15:04.5 |
HIP 12420 |
23.15 |
| 2026-06-19 00:00 |
02:40:44.52 |
+07:16:33.6 |
HIP 12420 |
24.63 |
| 2026-06-19 12:00 |
02:41:12.98 |
+07:18:01.8 |
HIP 12420 |
27.97 |
| 2026-06-20 00:00 |
02:41:41.38 |
+07:19:29.0 |
HIP 12607 |
27.33 |
| 2026-06-20 12:00 |
02:42:09.72 |
+07:20:55.4 |
HIP 12607 |
28.10 |
| 2026-06-21 00:00 |
02:42:38.00 |
+07:22:20.8 |
HIP 12771 |
22.64 |
| 2026-06-21 12:00 |
02:43:06.22 |
+07:23:45.3 |
HIP 12771 |
15.64 |
| 2026-06-22 00:00 |
02:43:34.37 |
+07:25:08.8 |
HIP 12771 |
8.86 |