| 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) |
| 2026-06-01 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 |
| 2026-06-02 12:00 |
06:06:49.24 |
+26:20:11.1 |
HIP 28945 |
3.23 |
| 2026-06-03 00:00 |
06:07:36.92 |
+26:20:22.9 |
HIP 28945 |
13.90 |
| 2026-06-03 12:00 |
06:08:24.69 |
+26:20:33.8 |
HIP 29209 |
18.46 |
| 2026-06-04 00:00 |
06:09:12.56 |
+26:20:43.9 |
HIP 29209 |
10.50 |
| 2026-06-04 12:00 |
06:10:00.52 |
+26:20:53.2 |
HIP 29209 |
10.49 |
| 2026-06-05 00:00 |
06:10:48.58 |
+26:21:01.6 |
HIP 29390 |
12.67 |
| 2026-06-05 12:00 |
06:11:36.73 |
+26:21:09.1 |
HIP 29390 |
6.36 |
| 2026-06-06 00:00 |
06:12:24.99 |
+26:21:15.8 |
HIP 29390 |
12.39 |
| 2026-06-06 12:00 |
06:13:13.33 |
+26:21:21.6 |
HIP 29390 |
22.38 |
| 2026-06-07 00:00 |
06:14:01.77 |
+26:21:26.6 |
HIP 29390 |
32.93 |
| 2026-06-07 12:00 |
06:14:50.30 |
+26:21:30.7 |
HIP 29826 |
28.25 |
| 2026-06-08 00:00 |
06:15:38.93 |
+26:21:33.9 |
HIP 29826 |
18.06 |
| 2026-06-08 12:00 |
06:16:27.65 |
+26:21:36.3 |
HIP 29826 |
9.58 |
| 2026-06-09 00:00 |
06:17:16.46 |
+26:21:37.7 |
HIP 29826 |
9.78 |
| 2026-06-09 12:00 |
06:18:05.36 |
+26:21:38.3 |
HIP 29826 |
18.42 |
| 2026-06-10 00:00 |
06:18:54.35 |
+26:21:38.0 |
HIP 30035 |
23.10 |
| 2026-06-10 12:00 |
06:19:43.43 |
+26:21:36.7 |
HIP 30035 |
23.65 |
| 2026-06-11 00:00 |
06:20:32.61 |
+26:21:34.6 |
HIP 30035 |
28.77 |
| 2026-06-11 12:00 |
06:21:21.87 |
+26:21:31.6 |
HIP 30306 |
23.49 |
| 2026-06-12 00:00 |
06:22:11.22 |
+26:21:27.6 |
HIP 30306 |
18.97 |
| 2026-06-12 12:00 |
06:23:00.66 |
+26:21:22.8 |
HIP 30306 |
20.30 |
| 2026-06-13 00:00 |
06:23:50.18 |
+26:21:17.0 |
HIP 30346 |
24.22 |
| 2026-06-13 12:00 |
06:24:39.79 |
+26:21:10.3 |
HIP 30644 |
26.53 |
| 2026-06-14 00:00 |
06:25:29.49 |
+26:21:02.7 |
HIP 30644 |
17.54 |
| 2026-06-14 12:00 |
06:26:19.27 |
+26:20:54.1 |
HIP 30644 |
12.64 |
| 2026-06-15 00:00 |
06:27:09.14 |
+26:20:44.6 |
HIP 30644 |
16.16 |
| 2026-06-15 12:00 |
06:27:59.09 |
+26:20:34.2 |
HIP 30839 |
18.51 |
| 2026-06-16 00:00 |
06:28:49.12 |
+26:20:22.8 |
HIP 30839 |
16.27 |
| 2026-06-16 12:00 |
06:29:39.23 |
+26:20:10.5 |
HIP 30839 |
20.94 |
| 2026-06-17 00:00 |
06:30:29.43 |
+26:19:57.2 |
HIP 31031 |
27.00 |
| 2026-06-17 12:00 |
06:31:19.70 |
+26:19:42.9 |
HIP 31232 |
23.59 |
| 2026-06-18 00:00 |
06:32:10.06 |
+26:19:27.8 |
HIP 31232 |
12.37 |
| 2026-06-18 12:00 |
06:33:00.49 |
+26:19:11.6 |
HIP 31232 |
2.00 |
| 2026-06-19 00:00 |
06:33:51.00 |
+26:18:54.5 |
HIP 31232 |
10.54 |
| 2026-06-19 12:00 |
06:34:41.59 |
+26:18:36.4 |
HIP 31232 |
21.80 |
| 2026-06-20 00:00 |
06:35:32.25 |
+26:18:17.4 |
HIP 31545 |
20.88 |
| 2026-06-20 12:00 |
06:36:22.99 |
+26:17:57.4 |
HIP 31545 |
19.37 |
| 2026-06-21 00:00 |
06:37:13.81 |
+26:17:36.4 |
HIP 31774 |
22.91 |
| 2026-06-21 12:00 |
06:38:04.70 |
+26:17:14.4 |
HIP 31774 |
14.99 |
| 2026-06-22 00:00 |
06:38:55.66 |
+26:16:51.4 |
HIP 31774 |
13.60 |