| Parameter |
Value |
| Designation |
P/2018 P4 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-11-07T08:17:57.094080Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:46Z |
| Obs used |
116 |
| NEO |
- |
| M1 |
11.600 |
| K1 |
10.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2018-08-08T12:01:59.232000Z |
| Discovery magnitude (MPC) |
20.60 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2018-09-13.0000000 |
| e |
0.44931114 |
| q (au) |
3.666142 |
| a (au) |
6.657375 |
| i (deg) |
23.112765 |
| Ω (om, deg) |
353.110347 |
| ω (w, deg) |
8.115551 |
| M (ma, deg) |
356.824339 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.263 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.263 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.852 |
| k |
0.999 |
| 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 |
11:39:42.83 |
+01:36:23.6 |
HIP 56856 |
5.80 |
| 2026-09-20 12:00 |
11:39:54.81 |
+01:34:48.9 |
HIP 56938 |
6.96 |
| 2026-09-21 00:00 |
11:40:06.78 |
+01:33:14.3 |
HIP 56938 |
4.72 |
| 2026-09-21 12:00 |
11:40:18.75 |
+01:31:39.6 |
HIP 56938 |
4.37 |
| 2026-09-22 00:00 |
11:40:30.72 |
+01:30:05.0 |
HIP 56938 |
6.23 |
| 2026-09-22 12:00 |
11:40:42.68 |
+01:28:30.4 |
HIP 56938 |
9.02 |
| 2026-09-23 00:00 |
11:40:54.63 |
+01:26:55.8 |
HIP 56938 |
12.11 |
| 2026-09-23 12:00 |
11:41:06.58 |
+01:25:21.2 |
HIP 56938 |
15.32 |
| 2026-09-24 00:00 |
11:41:18.52 |
+01:23:46.6 |
HIP 56938 |
18.59 |
| 2026-09-24 12:00 |
11:41:30.46 |
+01:22:12.1 |
HIP 56938 |
21.89 |
| 2026-09-25 00:00 |
11:41:42.38 |
+01:20:37.6 |
HIP 57042 |
21.00 |
| 2026-09-25 12:00 |
11:41:54.30 |
+01:19:03.1 |
HIP 57042 |
19.67 |
| 2026-09-26 00:00 |
11:42:06.21 |
+01:17:28.7 |
HIP 57042 |
18.85 |
| 2026-09-26 12:00 |
11:42:18.10 |
+01:15:54.3 |
HIP 57042 |
18.61 |
| 2026-09-27 00:00 |
11:42:29.99 |
+01:14:19.9 |
HIP 57042 |
18.98 |
| 2026-09-27 12:00 |
11:42:41.87 |
+01:12:45.6 |
HIP 57042 |
19.91 |
| 2026-09-28 00:00 |
11:42:53.74 |
+01:11:11.3 |
HIP 57042 |
21.33 |
| 2026-09-28 12:00 |
11:43:05.60 |
+01:09:37.1 |
HIP 57042 |
23.16 |
| 2026-09-29 00:00 |
11:43:17.44 |
+01:08:02.9 |
HIP 57152 |
22.27 |
| 2026-09-29 12:00 |
11:43:29.27 |
+01:06:28.7 |
HIP 57152 |
20.92 |
| 2026-09-30 00:00 |
11:43:41.09 |
+01:04:54.7 |
HIP 57152 |
20.05 |
| 2026-09-30 12:00 |
11:43:52.90 |
+01:03:20.6 |
HIP 57152 |
19.72 |
| 2026-10-01 00:00 |
11:44:04.69 |
+01:01:46.7 |
HIP 57317 |
17.21 |
| 2026-10-01 12:00 |
11:44:16.47 |
+01:00:12.8 |
HIP 57317 |
13.88 |
| 2026-10-02 00:00 |
11:44:28.24 |
+00:58:39.0 |
HIP 57317 |
10.56 |
| 2026-10-02 12:00 |
11:44:39.99 |
+00:57:05.2 |
HIP 57317 |
7.25 |
| 2026-10-03 00:00 |
11:44:51.72 |
+00:55:31.5 |
HIP 57317 |
3.99 |
| 2026-10-03 12:00 |
11:45:03.44 |
+00:53:57.9 |
HIP 57317 |
1.12 |
| 2026-10-04 00:00 |
11:45:15.14 |
+00:52:24.4 |
HIP 57317 |
2.93 |
| 2026-10-04 12:00 |
11:45:26.83 |
+00:50:50.9 |
HIP 57317 |
6.16 |
| 2026-10-05 00:00 |
11:45:38.50 |
+00:49:17.6 |
HIP 57317 |
9.43 |
| 2026-10-05 12:00 |
11:45:50.14 |
+00:47:44.3 |
HIP 57317 |
12.72 |
| 2026-10-06 00:00 |
11:46:01.77 |
+00:46:11.1 |
HIP 57317 |
16.01 |
| 2026-10-06 12:00 |
11:46:13.38 |
+00:44:38.1 |
HIP 57317 |
19.30 |
| 2026-10-07 00:00 |
11:46:24.97 |
+00:43:05.1 |
HIP 57548 |
20.48 |
| 2026-10-07 12:00 |
11:46:36.54 |
+00:41:32.2 |
HIP 57548 |
18.24 |
| 2026-10-08 00:00 |
11:46:48.09 |
+00:39:59.5 |
HIP 57548 |
16.35 |
| 2026-10-08 12:00 |
11:46:59.62 |
+00:38:26.8 |
HIP 57548 |
14.95 |
| 2026-10-09 00:00 |
11:47:11.12 |
+00:36:54.3 |
HIP 57548 |
14.18 |
| 2026-10-09 12:00 |
11:47:22.61 |
+00:35:21.8 |
HIP 57548 |
14.14 |
| 2026-10-10 00:00 |
11:47:34.06 |
+00:33:49.6 |
HIP 57548 |
14.84 |
| 2026-10-10 12:00 |
11:47:45.50 |
+00:32:17.4 |
HIP 57548 |
16.17 |
| 2026-10-11 00:00 |
11:47:56.91 |
+00:30:45.3 |
HIP 57548 |
17.99 |