P/2018 P4 (PANSTARRS)
| 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) |
| 2026-02-03 00:00 |
11:37:12.74 |
+04:23:53.9 |
HIP 56724 |
9.89 |
| 2026-02-03 12:00 |
11:37:05.31 |
+04:24:25.1 |
HIP 56724 |
11.78 |
| 2026-02-04 00:00 |
11:36:57.80 |
+04:24:56.7 |
HIP 56724 |
13.70 |
| 2026-02-04 12:00 |
11:36:50.21 |
+04:25:28.7 |
HIP 56724 |
15.65 |
| 2026-02-05 00:00 |
11:36:42.55 |
+04:26:01.1 |
HIP 56724 |
17.62 |
| 2026-02-05 12:00 |
11:36:34.81 |
+04:26:34.0 |
HIP 56724 |
19.61 |
| 2026-02-06 00:00 |
11:36:26.99 |
+04:27:07.3 |
HIP 56724 |
21.63 |
| 2026-02-06 12:00 |
11:36:19.10 |
+04:27:41.0 |
HIP 56724 |
23.67 |
| 2026-02-07 00:00 |
11:36:11.13 |
+04:28:15.0 |
HIP 56724 |
25.73 |
| 2026-02-07 12:00 |
11:36:03.09 |
+04:28:49.5 |
HIP 56724 |
27.81 |
| 2026-02-08 00:00 |
11:35:54.98 |
+04:29:24.4 |
HIP 56724 |
29.91 |
| 2026-02-08 12:00 |
11:35:46.80 |
+04:29:59.7 |
HIP 56724 |
32.03 |
| 2026-02-09 00:00 |
11:35:38.54 |
+04:30:35.4 |
HIP 56569 |
34.10 |
| 2026-02-09 12:00 |
11:35:30.22 |
+04:31:11.4 |
HIP 56569 |
34.92 |
| 2026-02-10 00:00 |
11:35:21.82 |
+04:31:47.8 |
HIP 56569 |
35.86 |
| 2026-02-10 12:00 |
11:35:13.36 |
+04:32:24.6 |
HIP 56378 |
36.41 |
| 2026-02-11 00:00 |
11:35:04.83 |
+04:33:01.7 |
HIP 56378 |
35.30 |
| 2026-02-11 12:00 |
11:34:56.23 |
+04:33:39.2 |
HIP 56378 |
34.28 |
| 2026-02-12 00:00 |
11:34:47.57 |
+04:34:17.1 |
HIP 56378 |
33.38 |
| 2026-02-12 12:00 |
11:34:38.85 |
+04:34:55.3 |
HIP 56378 |
32.60 |
| 2026-02-13 00:00 |
11:34:30.06 |
+04:35:33.8 |
HIP 56378 |
31.96 |
| 2026-02-13 12:00 |
11:34:21.20 |
+04:36:12.6 |
HIP 56378 |
31.48 |
| 2026-02-14 00:00 |
11:34:12.29 |
+04:36:51.8 |
HIP 56378 |
31.15 |
| 2026-02-14 12:00 |
11:34:03.31 |
+04:37:31.3 |
HIP 56378 |
31.00 |
| 2026-02-15 00:00 |
11:33:54.28 |
+04:38:11.1 |
HIP 56378 |
31.02 |
| 2026-02-15 12:00 |
11:33:45.18 |
+04:38:51.2 |
HIP 56378 |
31.22 |
| 2026-02-16 00:00 |
11:33:36.03 |
+04:39:31.6 |
HIP 56235 |
29.50 |
| 2026-02-16 12:00 |
11:33:26.83 |
+04:40:12.2 |
HIP 56235 |
27.45 |
| 2026-02-17 00:00 |
11:33:17.56 |
+04:40:53.2 |
HIP 56235 |
25.45 |
| 2026-02-17 12:00 |
11:33:08.25 |
+04:41:34.4 |
HIP 56235 |
23.52 |
| 2026-02-18 00:00 |
11:32:58.88 |
+04:42:15.9 |
HIP 56235 |
21.67 |
| 2026-02-18 12:00 |
11:32:49.46 |
+04:42:57.7 |
HIP 56235 |
19.94 |
| 2026-02-19 00:00 |
11:32:39.98 |
+04:43:39.7 |
HIP 56235 |
18.38 |
| 2026-02-19 12:00 |
11:32:30.46 |
+04:44:21.9 |
HIP 56235 |
17.01 |
| 2026-02-20 00:00 |
11:32:20.89 |
+04:45:04.4 |
HIP 56235 |
15.92 |
| 2026-02-20 12:00 |
11:32:11.27 |
+04:45:47.1 |
HIP 56235 |
15.15 |
| 2026-02-21 00:00 |
11:32:01.61 |
+04:46:30.1 |
HIP 56235 |
14.77 |
| 2026-02-21 12:00 |
11:31:51.90 |
+04:47:13.2 |
HIP 56235 |
14.81 |
| 2026-02-22 00:00 |
11:31:42.15 |
+04:47:56.6 |
HIP 56235 |
15.28 |
| 2026-02-22 12:00 |
11:31:32.35 |
+04:48:40.1 |
HIP 56235 |
16.15 |
| 2026-02-23 00:00 |
11:31:22.52 |
+04:49:23.8 |
HIP 56235 |
17.35 |
| 2026-02-23 12:00 |
11:31:12.64 |
+04:50:07.8 |
HIP 56235 |
18.84 |
| 2026-02-24 00:00 |
11:31:02.73 |
+04:50:51.9 |
HIP 56235 |
20.54 |