| 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
$$
M_a = (18.665 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
18.665 |
| n |
2.000 |
| gf |
0.987 |
| gb |
-0.786 |
| k |
0.943 |
| δ90 |
5.365 |
| 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) |
| 2026-05-12 00:00 |
05:34:19.65 |
+25:59:52.1 |
HIP 26177 |
9.81 |
| 2026-05-12 12:00 |
05:35:02.55 |
+26:00:34.7 |
HIP 26177 |
7.95 |
| 2026-05-13 00:00 |
05:35:45.57 |
+26:01:16.6 |
HIP 26332 |
11.14 |
| 2026-05-13 12:00 |
05:36:28.72 |
+26:01:57.9 |
HIP 26332 |
5.57 |
| 2026-05-14 00:00 |
05:37:12.00 |
+26:02:38.7 |
HIP 26332 |
11.28 |
| 2026-05-14 12:00 |
05:37:55.40 |
+26:03:18.8 |
HIP 26332 |
20.36 |
| 2026-05-15 00:00 |
05:38:38.92 |
+26:03:58.3 |
HIP 26566 |
15.38 |
| 2026-05-15 12:00 |
05:39:22.57 |
+26:04:37.1 |
HIP 26640 |
11.83 |
| 2026-05-16 00:00 |
05:40:06.34 |
+26:05:15.4 |
HIP 26640 |
12.46 |
| 2026-05-16 12:00 |
05:40:50.23 |
+26:05:53.0 |
HIP 26759 |
3.63 |
| 2026-05-17 00:00 |
05:41:34.24 |
+26:06:29.9 |
HIP 26759 |
6.84 |
| 2026-05-17 12:00 |
05:42:18.38 |
+26:07:06.2 |
HIP 26832 |
10.24 |
| 2026-05-18 00:00 |
05:43:02.63 |
+26:07:41.9 |
HIP 26832 |
17.59 |
| 2026-05-18 12:00 |
05:43:47.00 |
+26:08:16.9 |
HIP 27017 |
17.31 |
| 2026-05-19 00:00 |
05:44:31.49 |
+26:08:51.2 |
HIP 27110 |
12.88 |
| 2026-05-19 12:00 |
05:45:16.09 |
+26:09:24.8 |
HIP 27110 |
12.05 |
| 2026-05-20 00:00 |
05:46:00.81 |
+26:09:57.8 |
HIP 27110 |
18.06 |
| 2026-05-20 12:00 |
05:46:45.65 |
+26:10:30.1 |
HIP 27110 |
26.65 |
| 2026-05-21 00:00 |
05:47:30.60 |
+26:11:01.7 |
HIP 27110 |
36.04 |
| 2026-05-21 12:00 |
05:48:15.66 |
+26:11:32.6 |
HIP 27478 |
34.49 |
| 2026-05-22 00:00 |
05:49:00.83 |
+26:12:02.8 |
HIP 27612 |
25.56 |
| 2026-05-22 12:00 |
05:49:46.12 |
+26:12:32.2 |
HIP 27612 |
16.66 |
| 2026-05-23 00:00 |
05:50:31.52 |
+26:13:01.0 |
HIP 27612 |
10.42 |
| 2026-05-23 12:00 |
05:51:17.02 |
+26:13:29.1 |
HIP 27612 |
12.15 |
| 2026-05-24 00:00 |
05:52:02.64 |
+26:13:56.4 |
HIP 27808 |
19.12 |
| 2026-05-24 12:00 |
05:52:48.36 |
+26:14:23.0 |
HIP 27808 |
12.97 |
| 2026-05-25 00:00 |
05:53:34.19 |
+26:14:48.9 |
HIP 27881 |
12.00 |
| 2026-05-25 12:00 |
05:54:20.13 |
+26:15:14.0 |
HIP 27881 |
11.09 |
| 2026-05-26 00:00 |
05:55:06.18 |
+26:15:38.4 |
HIP 28032 |
15.05 |
| 2026-05-26 12:00 |
05:55:52.33 |
+26:16:02.0 |
HIP 28032 |
13.03 |
| 2026-05-27 00:00 |
05:56:38.58 |
+26:16:24.9 |
HIP 28032 |
18.11 |
| 2026-05-27 12:00 |
05:57:24.94 |
+26:16:47.0 |
HIP 28237 |
21.04 |
| 2026-05-28 00:00 |
05:58:11.41 |
+26:17:08.3 |
HIP 28237 |
20.08 |
| 2026-05-28 12:00 |
05:58:57.98 |
+26:17:28.9 |
HIP 28237 |
24.11 |
| 2026-05-29 00:00 |
05:59:44.65 |
+26:17:48.7 |
HIP 28237 |
31.29 |
| 2026-05-29 12:00 |
06:00:31.42 |
+26:18:07.7 |
HIP 28617 |
27.12 |
| 2026-05-30 00:00 |
06:01:18.30 |
+26:18:26.0 |
HIP 28617 |
17.19 |
| 2026-05-30 12:00 |
06:02:05.28 |
+26:18:43.4 |
HIP 28617 |
8.71 |
| 2026-05-31 00:00 |
06:02:52.36 |
+26:19:00.0 |
HIP 28617 |
8.86 |
| 2026-05-31 12:00 |
06:03:39.53 |
+26:19:15.9 |
HIP 28697 |
12.55 |
| 2026-06-01 00:00 |
06:04:26.81 |
+26:19:30.9 |
HIP 28697 |
17.02 |
| 2026-06-01 12:00 |
06:05:14.19 |
+26:19:45.2 |
HIP 28884 |
16.41 |
| 2026-06-02 00:00 |
06:06:01.67 |
+26:19:58.6 |
HIP 28945 |
7.46 |