P/2018 A5 (PANSTARRS)
| 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) |
| 2026-02-03 00:00 |
19:14:07.87 |
-28:22:08.5 |
HIP 94340 |
27.58 |
| 2026-02-03 12:00 |
19:14:24.89 |
-28:22:07.8 |
HIP 94425 |
29.68 |
| 2026-02-04 00:00 |
19:14:41.86 |
-28:22:07.1 |
HIP 94425 |
31.97 |
| 2026-02-04 12:00 |
19:14:58.79 |
-28:22:06.6 |
HIP 94752 |
30.09 |
| 2026-02-05 00:00 |
19:15:15.68 |
-28:22:06.2 |
HIP 94752 |
27.20 |
| 2026-02-05 12:00 |
19:15:32.52 |
-28:22:05.9 |
HIP 94752 |
24.54 |
| 2026-02-06 00:00 |
19:15:49.32 |
-28:22:05.8 |
HIP 94752 |
22.19 |
| 2026-02-06 12:00 |
19:16:06.08 |
-28:22:05.9 |
HIP 94752 |
20.24 |
| 2026-02-07 00:00 |
19:16:22.79 |
-28:22:06.0 |
HIP 94752 |
18.81 |
| 2026-02-07 12:00 |
19:16:39.45 |
-28:22:06.3 |
HIP 94752 |
18.04 |
| 2026-02-08 00:00 |
19:16:56.06 |
-28:22:06.8 |
HIP 94752 |
17.98 |
| 2026-02-08 12:00 |
19:17:12.63 |
-28:22:07.4 |
HIP 94752 |
18.65 |
| 2026-02-09 00:00 |
19:17:29.14 |
-28:22:08.2 |
HIP 94752 |
19.96 |
| 2026-02-09 12:00 |
19:17:45.61 |
-28:22:09.1 |
HIP 94914 |
16.87 |
| 2026-02-10 00:00 |
19:18:02.03 |
-28:22:10.1 |
HIP 94914 |
13.85 |
| 2026-02-10 12:00 |
19:18:18.39 |
-28:22:11.4 |
HIP 94914 |
11.20 |
| 2026-02-11 00:00 |
19:18:34.70 |
-28:22:12.8 |
HIP 94914 |
9.23 |
| 2026-02-11 12:00 |
19:18:50.96 |
-28:22:14.3 |
HIP 94914 |
8.41 |
| 2026-02-12 00:00 |
19:19:07.17 |
-28:22:16.0 |
HIP 94914 |
9.05 |
| 2026-02-12 12:00 |
19:19:23.32 |
-28:22:17.9 |
HIP 94914 |
10.88 |
| 2026-02-13 00:00 |
19:19:39.42 |
-28:22:20.0 |
HIP 94914 |
13.42 |
| 2026-02-13 12:00 |
19:19:55.46 |
-28:22:22.3 |
HIP 94985 |
14.38 |
| 2026-02-14 00:00 |
19:20:11.45 |
-28:22:24.7 |
HIP 94985 |
15.58 |
| 2026-02-14 12:00 |
19:20:27.37 |
-28:22:27.3 |
HIP 94985 |
17.40 |
| 2026-02-15 00:00 |
19:20:43.24 |
-28:22:30.1 |
HIP 94985 |
19.68 |
| 2026-02-15 12:00 |
19:20:59.05 |
-28:22:33.0 |
HIP 94985 |
22.25 |
| 2026-02-16 00:00 |
19:21:14.80 |
-28:22:36.2 |
HIP 95182 |
23.06 |
| 2026-02-16 12:00 |
19:21:30.49 |
-28:22:39.6 |
HIP 95182 |
22.19 |
| 2026-02-17 00:00 |
19:21:46.12 |
-28:22:43.1 |
HIP 95278 |
19.75 |
| 2026-02-17 12:00 |
19:22:01.69 |
-28:22:46.9 |
HIP 95278 |
16.86 |
| 2026-02-18 00:00 |
19:22:17.19 |
-28:22:50.8 |
HIP 95278 |
14.20 |
| 2026-02-18 12:00 |
19:22:32.63 |
-28:22:54.9 |
HIP 95278 |
11.95 |
| 2026-02-19 00:00 |
19:22:48.01 |
-28:22:59.3 |
HIP 95278 |
10.33 |
| 2026-02-19 12:00 |
19:23:03.32 |
-28:23:03.9 |
HIP 95278 |
9.67 |
| 2026-02-20 00:00 |
19:23:18.57 |
-28:23:08.6 |
HIP 95278 |
10.14 |
| 2026-02-20 12:00 |
19:23:33.74 |
-28:23:13.6 |
HIP 95278 |
11.59 |
| 2026-02-21 00:00 |
19:23:48.85 |
-28:23:18.8 |
HIP 95278 |
13.71 |
| 2026-02-21 12:00 |
19:24:03.90 |
-28:23:24.2 |
HIP 95278 |
16.21 |
| 2026-02-22 00:00 |
19:24:18.87 |
-28:23:29.9 |
HIP 95278 |
18.95 |
| 2026-02-22 12:00 |
19:24:33.78 |
-28:23:35.7 |
HIP 95356 |
20.16 |
| 2026-02-23 00:00 |
19:24:48.61 |
-28:23:41.8 |
HIP 95519 |
21.21 |
| 2026-02-23 12:00 |
19:25:03.37 |
-28:23:48.1 |
HIP 95519 |
19.39 |
| 2026-02-24 00:00 |
19:25:18.07 |
-28:23:54.7 |
HIP 95519 |
17.97 |