| Parameter |
Value |
| Designation |
P/2018 A5 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2017-09-23T19:44:28.916160Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:40Z |
| Obs used |
36 |
| NEO |
- |
| M1 |
17.700 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-12-11.0000000 |
| e |
0.52304780 |
| q (au) |
2.693821 |
| a (au) |
5.647990 |
| i (deg) |
23.577029 |
| Ω (om, deg) |
87.829721 |
| ω (w, deg) |
359.679511 |
| M (ma, deg) |
5.740433 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.815 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.815 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.999 |
| δ90 |
1.000 |
| 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) |
| 2026-05-12 00:00 |
19:42:25.19 |
-29:46:20.6 |
HIP 96930 |
9.14 |
| 2026-05-12 12:00 |
19:42:21.86 |
-29:47:20.8 |
HIP 96930 |
9.93 |
| 2026-05-13 00:00 |
19:42:18.39 |
-29:48:21.3 |
HIP 96930 |
10.81 |
| 2026-05-13 12:00 |
19:42:14.78 |
-29:49:22.0 |
HIP 96930 |
11.76 |
| 2026-05-14 00:00 |
19:42:11.03 |
-29:50:23.1 |
HIP 96930 |
12.77 |
| 2026-05-14 12:00 |
19:42:07.13 |
-29:51:24.4 |
HIP 96930 |
13.84 |
| 2026-05-15 00:00 |
19:42:03.09 |
-29:52:25.9 |
HIP 96930 |
14.96 |
| 2026-05-15 12:00 |
19:41:58.91 |
-29:53:27.8 |
HIP 96877 |
15.12 |
| 2026-05-16 00:00 |
19:41:54.59 |
-29:54:29.9 |
HIP 96877 |
13.83 |
| 2026-05-16 12:00 |
19:41:50.13 |
-29:55:32.3 |
HIP 96877 |
12.56 |
| 2026-05-17 00:00 |
19:41:45.52 |
-29:56:34.9 |
HIP 96877 |
11.31 |
| 2026-05-17 12:00 |
19:41:40.78 |
-29:57:37.8 |
HIP 96877 |
10.11 |
| 2026-05-18 00:00 |
19:41:35.89 |
-29:58:40.9 |
HIP 96877 |
8.98 |
| 2026-05-18 12:00 |
19:41:30.87 |
-29:59:44.2 |
HIP 96877 |
7.97 |
| 2026-05-19 00:00 |
19:41:25.71 |
-30:00:47.8 |
HIP 96877 |
7.15 |
| 2026-05-19 12:00 |
19:41:20.40 |
-30:01:51.6 |
HIP 96877 |
6.60 |
| 2026-05-20 00:00 |
19:41:14.96 |
-30:02:55.6 |
HIP 96877 |
6.41 |
| 2026-05-20 12:00 |
19:41:09.38 |
-30:03:59.9 |
HIP 96877 |
6.63 |
| 2026-05-21 00:00 |
19:41:03.66 |
-30:05:04.3 |
HIP 96877 |
7.24 |
| 2026-05-21 12:00 |
19:40:57.81 |
-30:06:09.0 |
HIP 96877 |
8.17 |
| 2026-05-22 00:00 |
19:40:51.82 |
-30:07:13.8 |
HIP 96877 |
9.33 |
| 2026-05-22 12:00 |
19:40:45.69 |
-30:08:18.9 |
HIP 96877 |
10.67 |
| 2026-05-23 00:00 |
19:40:39.43 |
-30:09:24.1 |
HIP 96877 |
12.12 |
| 2026-05-23 12:00 |
19:40:33.03 |
-30:10:29.5 |
HIP 96877 |
13.68 |
| 2026-05-24 00:00 |
19:40:26.50 |
-30:11:35.1 |
HIP 96690 |
13.18 |
| 2026-05-24 12:00 |
19:40:19.83 |
-30:12:40.9 |
HIP 96690 |
11.94 |
| 2026-05-25 00:00 |
19:40:13.04 |
-30:13:46.8 |
HIP 96690 |
10.83 |
| 2026-05-25 12:00 |
19:40:06.10 |
-30:14:52.9 |
HIP 96690 |
9.91 |
| 2026-05-26 00:00 |
19:39:59.04 |
-30:15:59.1 |
HIP 96690 |
9.26 |
| 2026-05-26 12:00 |
19:39:51.85 |
-30:17:05.4 |
HIP 96690 |
8.95 |
| 2026-05-27 00:00 |
19:39:44.52 |
-30:18:12.0 |
HIP 96690 |
9.03 |
| 2026-05-27 12:00 |
19:39:37.06 |
-30:19:18.6 |
HIP 96690 |
9.51 |
| 2026-05-28 00:00 |
19:39:29.48 |
-30:20:25.4 |
HIP 96638 |
8.81 |
| 2026-05-28 12:00 |
19:39:21.76 |
-30:21:32.3 |
HIP 96638 |
7.92 |
| 2026-05-29 00:00 |
19:39:13.92 |
-30:22:39.3 |
HIP 96638 |
7.45 |
| 2026-05-29 12:00 |
19:39:05.95 |
-30:23:46.4 |
HIP 96638 |
7.52 |
| 2026-05-30 00:00 |
19:38:57.85 |
-30:24:53.6 |
HIP 96638 |
8.12 |
| 2026-05-30 12:00 |
19:38:49.63 |
-30:26:00.9 |
HIP 96638 |
9.17 |
| 2026-05-31 00:00 |
19:38:41.28 |
-30:27:08.3 |
HIP 96638 |
10.54 |
| 2026-05-31 12:00 |
19:38:32.80 |
-30:28:15.8 |
HIP 96638 |
12.14 |
| 2026-06-01 00:00 |
19:38:24.20 |
-30:29:23.3 |
HIP 96562 |
13.61 |
| 2026-06-01 12:00 |
19:38:15.48 |
-30:30:31.0 |
HIP 96562 |
13.78 |
| 2026-06-02 00:00 |
19:38:06.63 |
-30:31:38.7 |
HIP 96562 |
14.29 |