| Parameter |
Value |
| Designation |
386P/PANSTARRS |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-06-21T04:09:09.524160Z |
| Orbit solution date (soln_date, UTC) |
2021-05-31T22:43:09Z |
| Obs used |
118 |
| NEO |
- |
| M1 |
13.500 |
| K1 |
12.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-09-30.0000000 |
| e |
0.41776560 |
| q (au) |
2.359299 |
| a (au) |
4.052147 |
| i (deg) |
15.244307 |
| Ω (om, deg) |
134.979116 |
| ω (w, deg) |
353.350939 |
| M (ma, deg) |
144.492270 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.414 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.414 |
| n |
2.000 |
| gf |
0.980 |
| gb |
-0.503 |
| k |
1.000 |
| δ90 |
9.995 |
| 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) |
| 2026-05-12 00:00 |
23:44:34.81 |
-08:59:04.0 |
HIP 117122 |
8.20 |
| 2026-05-12 12:00 |
23:44:54.33 |
-08:57:58.7 |
HIP 117122 |
8.02 |
| 2026-05-13 00:00 |
23:45:13.76 |
-08:56:54.2 |
HIP 117122 |
10.50 |
| 2026-05-13 12:00 |
23:45:33.11 |
-08:55:50.5 |
HIP 117122 |
14.28 |
| 2026-05-14 00:00 |
23:45:52.38 |
-08:54:47.7 |
HIP 117258 |
11.44 |
| 2026-05-14 12:00 |
23:46:11.55 |
-08:53:45.7 |
HIP 117258 |
8.20 |
| 2026-05-15 00:00 |
23:46:30.64 |
-08:52:44.6 |
HIP 117274 |
5.09 |
| 2026-05-15 12:00 |
23:46:49.64 |
-08:51:44.3 |
HIP 117274 |
2.09 |
| 2026-05-16 00:00 |
23:47:08.55 |
-08:50:44.9 |
HIP 117274 |
5.35 |
| 2026-05-16 12:00 |
23:47:27.37 |
-08:49:46.4 |
HIP 117274 |
9.90 |
| 2026-05-17 00:00 |
23:47:46.10 |
-08:48:48.7 |
HIP 117274 |
14.55 |
| 2026-05-17 12:00 |
23:48:04.74 |
-08:47:51.9 |
HIP 117274 |
19.21 |
| 2026-05-18 00:00 |
23:48:23.28 |
-08:46:56.1 |
HIP 117274 |
23.86 |
| 2026-05-18 12:00 |
23:48:41.73 |
-08:46:01.1 |
HIP 117274 |
28.49 |
| 2026-05-19 00:00 |
23:49:00.08 |
-08:45:07.0 |
HIP 117274 |
33.11 |
| 2026-05-19 12:00 |
23:49:18.34 |
-08:44:13.9 |
HIP 117439 |
36.38 |
| 2026-05-20 00:00 |
23:49:36.51 |
-08:43:21.6 |
HIP 117439 |
36.80 |
| 2026-05-20 12:00 |
23:49:54.57 |
-08:42:30.3 |
HIP 117439 |
37.78 |
| 2026-05-21 00:00 |
23:50:12.54 |
-08:41:39.9 |
HIP 117439 |
39.27 |
| 2026-05-21 12:00 |
23:50:30.41 |
-08:40:50.4 |
HIP 117743 |
35.61 |
| 2026-05-22 00:00 |
23:50:48.19 |
-08:40:01.9 |
HIP 117743 |
31.90 |
| 2026-05-22 12:00 |
23:51:05.86 |
-08:39:14.3 |
HIP 117743 |
28.41 |
| 2026-05-23 00:00 |
23:51:23.43 |
-08:38:27.6 |
HIP 117743 |
25.23 |
| 2026-05-23 12:00 |
23:51:40.90 |
-08:37:41.9 |
HIP 117743 |
22.48 |
| 2026-05-24 00:00 |
23:51:58.27 |
-08:36:57.2 |
HIP 117743 |
20.31 |
| 2026-05-24 12:00 |
23:52:15.54 |
-08:36:13.4 |
HIP 117743 |
18.91 |
| 2026-05-25 00:00 |
23:52:32.71 |
-08:35:30.6 |
HIP 117743 |
18.43 |
| 2026-05-25 12:00 |
23:52:49.77 |
-08:34:48.7 |
HIP 117743 |
18.92 |
| 2026-05-26 00:00 |
23:53:06.72 |
-08:34:07.8 |
HIP 117743 |
20.29 |
| 2026-05-26 12:00 |
23:53:23.58 |
-08:33:27.9 |
HIP 117743 |
22.38 |
| 2026-05-27 00:00 |
23:53:40.32 |
-08:32:49.0 |
HIP 117924 |
22.34 |
| 2026-05-27 12:00 |
23:53:56.96 |
-08:32:11.1 |
HIP 117924 |
18.23 |
| 2026-05-28 00:00 |
23:54:13.49 |
-08:31:34.2 |
HIP 117924 |
14.17 |
| 2026-05-28 12:00 |
23:54:29.92 |
-08:30:58.3 |
HIP 117924 |
10.20 |
| 2026-05-29 00:00 |
23:54:46.23 |
-08:30:23.4 |
HIP 117924 |
6.45 |
| 2026-05-29 12:00 |
23:55:02.44 |
-08:29:49.5 |
HIP 117924 |
3.52 |
| 2026-05-30 00:00 |
23:55:18.53 |
-08:29:16.6 |
HIP 117924 |
3.99 |
| 2026-05-30 12:00 |
23:55:34.52 |
-08:28:44.8 |
HIP 117924 |
7.17 |
| 2026-05-31 00:00 |
23:55:50.39 |
-08:28:14.0 |
HIP 117924 |
10.87 |
| 2026-05-31 12:00 |
23:56:06.15 |
-08:27:44.2 |
HIP 117924 |
14.68 |
| 2026-06-01 00:00 |
23:56:21.80 |
-08:27:15.5 |
HIP 117924 |
18.52 |
| 2026-06-01 12:00 |
23:56:37.34 |
-08:26:47.8 |
HIP 117924 |
22.34 |
| 2026-06-02 00:00 |
23:56:52.75 |
-08:26:21.1 |
HIP 117924 |
26.16 |