| Parameter |
Value |
| Designation |
503P/PANSTARRS |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-11-12T13:38:28.222080Z |
| Orbit solution date (soln_date, UTC) |
2025-07-07T14:12:36Z |
| Obs used |
123 |
| NEO |
- |
| M1 |
14.400 |
| K1 |
11.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2018-06-03T06:49:46.848000Z |
| Discovery magnitude (MPC) |
20.00 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-10-11.0000000 |
| e |
0.48303012 |
| q (au) |
1.885951 |
| a (au) |
3.648087 |
| i (deg) |
10.594784 |
| Ω (om, deg) |
268.626025 |
| ω (w, deg) |
17.915078 |
| M (ma, deg) |
47.022821 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.375 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.375 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
02:16:01.27 |
+26:54:02.2 |
HIP 10582 |
8.01 |
| 2026-09-20 12:00 |
02:15:45.56 |
+26:53:34.0 |
HIP 10582 |
10.08 |
| 2026-09-21 00:00 |
02:15:29.54 |
+26:53:03.3 |
HIP 10582 |
12.90 |
| 2026-09-21 12:00 |
02:15:13.21 |
+26:52:30.0 |
HIP 10582 |
16.11 |
| 2026-09-22 00:00 |
02:14:56.58 |
+26:51:54.0 |
HIP 10402 |
18.73 |
| 2026-09-22 12:00 |
02:14:39.65 |
+26:51:15.5 |
HIP 10402 |
15.99 |
| 2026-09-23 00:00 |
02:14:22.42 |
+26:50:34.4 |
HIP 10402 |
13.71 |
| 2026-09-23 12:00 |
02:14:04.89 |
+26:49:50.6 |
HIP 10402 |
12.24 |
| 2026-09-24 00:00 |
02:13:47.08 |
+26:49:04.2 |
HIP 10402 |
11.95 |
| 2026-09-24 12:00 |
02:13:28.99 |
+26:48:15.2 |
HIP 10402 |
12.99 |
| 2026-09-25 00:00 |
02:13:10.61 |
+26:47:23.6 |
HIP 10402 |
15.13 |
| 2026-09-25 12:00 |
02:12:51.95 |
+26:46:29.3 |
HIP 10402 |
18.05 |
| 2026-09-26 00:00 |
02:12:33.02 |
+26:45:32.4 |
HIP 10402 |
21.46 |
| 2026-09-26 12:00 |
02:12:13.83 |
+26:44:32.9 |
HIP 10402 |
25.21 |
| 2026-09-27 00:00 |
02:11:54.37 |
+26:43:30.8 |
HIP 10402 |
29.19 |
| 2026-09-27 12:00 |
02:11:34.64 |
+26:42:26.0 |
HIP 10098 |
26.77 |
| 2026-09-28 00:00 |
02:11:14.67 |
+26:41:18.6 |
HIP 10098 |
22.37 |
| 2026-09-28 12:00 |
02:10:54.44 |
+26:40:08.5 |
HIP 10098 |
18.01 |
| 2026-09-29 00:00 |
02:10:33.96 |
+26:38:55.8 |
HIP 10098 |
13.78 |
| 2026-09-29 12:00 |
02:10:13.24 |
+26:37:40.5 |
HIP 10098 |
9.95 |
| 2026-09-30 00:00 |
02:09:52.28 |
+26:36:22.5 |
HIP 10098 |
7.31 |
| 2026-09-30 12:00 |
02:09:31.09 |
+26:35:01.9 |
HIP 10098 |
7.43 |
| 2026-10-01 00:00 |
02:09:09.67 |
+26:33:38.7 |
HIP 10098 |
10.29 |
| 2026-10-01 12:00 |
02:08:48.02 |
+26:32:12.9 |
HIP 10098 |
14.41 |
| 2026-10-02 00:00 |
02:08:26.16 |
+26:30:44.4 |
HIP 10098 |
19.03 |
| 2026-10-02 12:00 |
02:08:04.08 |
+26:29:13.3 |
HIP 9864 |
18.15 |
| 2026-10-03 00:00 |
02:07:41.79 |
+26:27:39.6 |
HIP 9864 |
13.19 |
| 2026-10-03 12:00 |
02:07:19.31 |
+26:26:03.4 |
HIP 9864 |
8.47 |
| 2026-10-04 00:00 |
02:06:56.62 |
+26:24:24.5 |
HIP 9864 |
5.01 |
| 2026-10-04 12:00 |
02:06:33.74 |
+26:22:43.0 |
HIP 9864 |
5.97 |
| 2026-10-05 00:00 |
02:06:10.68 |
+26:20:59.0 |
HIP 9864 |
10.26 |
| 2026-10-05 12:00 |
02:05:47.43 |
+26:19:12.4 |
HIP 9864 |
15.34 |
| 2026-10-06 00:00 |
02:05:24.01 |
+26:17:23.2 |
HIP 9688 |
10.68 |
| 2026-10-06 12:00 |
02:05:00.42 |
+26:15:31.5 |
HIP 9688 |
5.16 |
| 2026-10-07 00:00 |
02:04:36.67 |
+26:13:37.3 |
HIP 9688 |
1.46 |
| 2026-10-07 12:00 |
02:04:12.76 |
+26:11:40.6 |
HIP 9688 |
6.50 |
| 2026-10-08 00:00 |
02:03:48.70 |
+26:09:41.4 |
HIP 9688 |
12.19 |
| 2026-10-08 12:00 |
02:03:24.50 |
+26:07:39.7 |
HIP 9621 |
12.00 |
| 2026-10-09 00:00 |
02:03:00.16 |
+26:05:35.6 |
HIP 9621 |
12.91 |
| 2026-10-09 12:00 |
02:02:35.69 |
+26:03:29.0 |
HIP 9621 |
16.07 |
| 2026-10-10 00:00 |
02:02:11.10 |
+26:01:20.0 |
HIP 9621 |
20.49 |
| 2026-10-10 12:00 |
02:01:46.39 |
+25:59:08.6 |
HIP 9621 |
25.55 |
| 2026-10-11 00:00 |
02:01:21.57 |
+25:56:54.9 |
HIP 9621 |
30.97 |