| Parameter |
Value |
| Designation |
P/2018 H2 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-01-23T11:01:35.495040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:43Z |
| Obs used |
169 |
| NEO |
- |
| M1 |
17.000 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2018-04-16T12:40:08.832000Z |
| Discovery magnitude (MPC) |
19.90 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2018-04-26.0000000 |
| e |
0.54004634 |
| q (au) |
2.027090 |
| a (au) |
4.407161 |
| i (deg) |
7.388853 |
| Ω (om, deg) |
68.455880 |
| ω (w, deg) |
120.229629 |
| M (ma, deg) |
9.858205 |
Magnitude
Scatter + Global Linear
$$
M_a = (18.598 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
18.598 |
| n |
2.000 |
| gf |
0.982 |
| gb |
-0.786 |
| k |
0.949 |
| δ90 |
8.021 |
| 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 |
09:24:01.27 |
+20:17:50.7 |
HIP 46076 |
5.20 |
| 2026-09-20 12:00 |
09:24:57.96 |
+20:14:18.9 |
HIP 46249 |
13.97 |
| 2026-09-21 00:00 |
09:25:54.64 |
+20:10:46.3 |
HIP 46249 |
12.28 |
| 2026-09-21 12:00 |
09:26:51.32 |
+20:07:12.8 |
HIP 46292 |
20.59 |
| 2026-09-22 00:00 |
09:27:48.00 |
+20:03:38.5 |
HIP 46419 |
14.37 |
| 2026-09-22 12:00 |
09:28:44.66 |
+20:00:03.4 |
HIP 46419 |
15.49 |
| 2026-09-23 00:00 |
09:29:41.33 |
+19:56:27.6 |
HIP 46419 |
25.57 |
| 2026-09-23 12:00 |
09:30:37.98 |
+19:52:50.9 |
HIP 46751 |
17.24 |
| 2026-09-24 00:00 |
09:31:34.63 |
+19:49:13.4 |
HIP 46751 |
11.34 |
| 2026-09-24 12:00 |
09:32:31.28 |
+19:45:35.2 |
HIP 46838 |
6.17 |
| 2026-09-25 00:00 |
09:33:27.92 |
+19:41:56.1 |
HIP 46838 |
14.55 |
| 2026-09-25 12:00 |
09:34:24.55 |
+19:38:16.3 |
HIP 46838 |
27.71 |
| 2026-09-26 00:00 |
09:35:21.17 |
+19:34:35.7 |
HIP 47140 |
16.11 |
| 2026-09-26 12:00 |
09:36:17.79 |
+19:30:54.4 |
HIP 47140 |
4.44 |
| 2026-09-27 00:00 |
09:37:14.40 |
+19:27:12.2 |
HIP 47140 |
12.77 |
| 2026-09-27 12:00 |
09:38:11.00 |
+19:23:29.4 |
HIP 47140 |
26.27 |
| 2026-09-28 00:00 |
09:39:07.60 |
+19:19:45.7 |
HIP 47140 |
40.02 |
| 2026-09-28 12:00 |
09:40:04.19 |
+19:16:01.4 |
HIP 47545 |
28.80 |
| 2026-09-29 00:00 |
09:41:00.77 |
+19:12:16.3 |
HIP 47545 |
17.37 |
| 2026-09-29 12:00 |
09:41:57.34 |
+19:08:30.4 |
HIP 47545 |
12.63 |
| 2026-09-30 00:00 |
09:42:53.91 |
+19:04:43.8 |
HIP 47545 |
20.07 |
| 2026-09-30 12:00 |
09:43:50.46 |
+19:00:56.5 |
HIP 47786 |
10.66 |
| 2026-10-01 00:00 |
09:44:47.01 |
+18:57:08.5 |
HIP 47786 |
4.08 |
| 2026-10-01 12:00 |
09:45:43.55 |
+18:53:19.8 |
HIP 47909 |
12.47 |
| 2026-10-02 00:00 |
09:46:40.08 |
+18:49:30.4 |
HIP 47909 |
14.21 |
| 2026-10-02 12:00 |
09:47:36.60 |
+18:45:40.3 |
HIP 48103 |
12.23 |
| 2026-10-03 00:00 |
09:48:33.11 |
+18:41:49.5 |
HIP 48103 |
6.71 |
| 2026-10-03 12:00 |
09:49:29.61 |
+18:37:58.1 |
HIP 48196 |
1.22 |
| 2026-10-04 00:00 |
09:50:26.09 |
+18:34:05.9 |
HIP 48196 |
13.78 |
| 2026-10-04 12:00 |
09:51:22.57 |
+18:30:13.1 |
HIP 48366 |
6.52 |
| 2026-10-05 00:00 |
09:52:19.03 |
+18:26:19.7 |
HIP 48366 |
10.10 |
| 2026-10-05 12:00 |
09:53:15.48 |
+18:22:25.6 |
HIP 48562 |
17.94 |
| 2026-10-06 00:00 |
09:54:11.92 |
+18:18:30.9 |
HIP 48562 |
6.51 |
| 2026-10-06 12:00 |
09:55:08.35 |
+18:14:35.6 |
HIP 48562 |
12.34 |
| 2026-10-07 00:00 |
09:56:04.76 |
+18:10:39.6 |
HIP 48562 |
25.53 |
| 2026-10-07 12:00 |
09:57:01.15 |
+18:06:43.0 |
HIP 48843 |
17.91 |
| 2026-10-08 00:00 |
09:57:57.53 |
+18:02:45.9 |
HIP 48843 |
18.64 |
| 2026-10-08 12:00 |
09:58:53.90 |
+17:58:48.1 |
HIP 48843 |
27.64 |
| 2026-10-09 00:00 |
09:59:50.24 |
+17:54:49.8 |
HIP 49061 |
24.14 |
| 2026-10-09 12:00 |
10:00:46.58 |
+17:50:50.9 |
HIP 49061 |
16.82 |
| 2026-10-10 00:00 |
10:01:42.89 |
+17:46:51.4 |
HIP 49061 |
19.34 |
| 2026-10-10 12:00 |
10:02:39.19 |
+17:42:51.4 |
HIP 49136 |
23.05 |
| 2026-10-11 00:00 |
10:03:35.46 |
+17:38:50.9 |
HIP 49406 |
22.59 |