| Parameter |
Value |
| Designation |
P/2016 A3 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2017-04-13T17:31:26.886720Z |
| Orbit solution date (soln_date, UTC) |
2022-07-31T01:43:22Z |
| Obs used |
198 |
| NEO |
- |
| M1 |
4.300 |
| K1 |
17.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-05-17.0000000 |
| e |
0.38019712 |
| q (au) |
4.789503 |
| a (au) |
7.727462 |
| i (deg) |
8.593880 |
| Ω (om, deg) |
187.794592 |
| ω (w, deg) |
338.486358 |
| M (ma, deg) |
1.526509 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.010 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.010 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.971 |
| k |
1.000 |
| δ90 |
10.000 |
| 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) |
| 2026-09-20 00:00 |
22:13:13.00 |
-05:43:56.5 |
HIP 109783 |
15.25 |
| 2026-09-20 12:00 |
22:13:05.77 |
-05:44:50.3 |
HIP 109783 |
17.02 |
| 2026-09-21 00:00 |
22:12:58.58 |
-05:45:44.1 |
HIP 109783 |
18.83 |
| 2026-09-21 12:00 |
22:12:51.45 |
-05:46:37.6 |
HIP 109783 |
20.67 |
| 2026-09-22 00:00 |
22:12:44.36 |
-05:47:31.0 |
HIP 109783 |
22.51 |
| 2026-09-22 12:00 |
22:12:37.33 |
-05:48:24.2 |
HIP 109526 |
21.92 |
| 2026-09-23 00:00 |
22:12:30.35 |
-05:49:17.2 |
HIP 109526 |
20.03 |
| 2026-09-23 12:00 |
22:12:23.42 |
-05:50:10.1 |
HIP 109526 |
18.16 |
| 2026-09-24 00:00 |
22:12:16.54 |
-05:51:02.7 |
HIP 109526 |
16.32 |
| 2026-09-24 12:00 |
22:12:09.71 |
-05:51:55.2 |
HIP 109526 |
14.52 |
| 2026-09-25 00:00 |
22:12:02.94 |
-05:52:47.4 |
HIP 109526 |
12.76 |
| 2026-09-25 12:00 |
22:11:56.22 |
-05:53:39.5 |
HIP 109526 |
11.07 |
| 2026-09-26 00:00 |
22:11:49.56 |
-05:54:31.3 |
HIP 109526 |
9.45 |
| 2026-09-26 12:00 |
22:11:42.95 |
-05:55:22.9 |
HIP 109526 |
7.96 |
| 2026-09-27 00:00 |
22:11:36.40 |
-05:56:14.3 |
HIP 109526 |
6.67 |
| 2026-09-27 12:00 |
22:11:29.91 |
-05:57:05.5 |
HIP 109526 |
5.70 |
| 2026-09-28 00:00 |
22:11:23.48 |
-05:57:56.4 |
HIP 109526 |
5.21 |
| 2026-09-28 12:00 |
22:11:17.10 |
-05:58:47.1 |
HIP 109526 |
5.33 |
| 2026-09-29 00:00 |
22:11:10.79 |
-05:59:37.5 |
HIP 109526 |
6.01 |
| 2026-09-29 12:00 |
22:11:04.53 |
-06:00:27.7 |
HIP 109526 |
7.07 |
| 2026-09-30 00:00 |
22:10:58.34 |
-06:01:17.7 |
HIP 109526 |
8.36 |
| 2026-09-30 12:00 |
22:10:52.21 |
-06:02:07.4 |
HIP 109526 |
9.79 |
| 2026-10-01 00:00 |
22:10:46.14 |
-06:02:56.9 |
HIP 109526 |
11.29 |
| 2026-10-01 12:00 |
22:10:40.13 |
-06:03:46.0 |
HIP 109526 |
12.83 |
| 2026-10-02 00:00 |
22:10:34.19 |
-06:04:35.0 |
HIP 109526 |
14.40 |
| 2026-10-02 12:00 |
22:10:28.31 |
-06:05:23.6 |
HIP 109526 |
15.97 |
| 2026-10-03 00:00 |
22:10:22.50 |
-06:06:12.0 |
HIP 109526 |
17.55 |
| 2026-10-03 12:00 |
22:10:16.75 |
-06:07:00.0 |
HIP 109385 |
19.10 |
| 2026-10-04 00:00 |
22:10:11.07 |
-06:07:47.8 |
HIP 109385 |
17.73 |
| 2026-10-04 12:00 |
22:10:05.46 |
-06:08:35.3 |
HIP 109385 |
16.41 |
| 2026-10-05 00:00 |
22:09:59.92 |
-06:09:22.5 |
HIP 109385 |
15.17 |
| 2026-10-05 12:00 |
22:09:54.44 |
-06:10:09.4 |
HIP 109385 |
14.00 |
| 2026-10-06 00:00 |
22:09:49.03 |
-06:10:56.0 |
HIP 109385 |
12.92 |
| 2026-10-06 12:00 |
22:09:43.70 |
-06:11:42.3 |
HIP 109385 |
11.96 |
| 2026-10-07 00:00 |
22:09:38.43 |
-06:12:28.2 |
HIP 109385 |
11.13 |
| 2026-10-07 12:00 |
22:09:33.24 |
-06:13:13.9 |
HIP 109385 |
10.45 |
| 2026-10-08 00:00 |
22:09:28.12 |
-06:13:59.2 |
HIP 109385 |
9.96 |
| 2026-10-08 12:00 |
22:09:23.07 |
-06:14:44.1 |
HIP 109385 |
9.68 |
| 2026-10-09 00:00 |
22:09:18.09 |
-06:15:28.8 |
HIP 109385 |
9.60 |
| 2026-10-09 12:00 |
22:09:13.19 |
-06:16:13.1 |
HIP 109385 |
9.73 |
| 2026-10-10 00:00 |
22:09:08.36 |
-06:16:57.0 |
HIP 109385 |
10.05 |
| 2026-10-10 12:00 |
22:09:03.61 |
-06:17:40.6 |
HIP 109385 |
10.54 |
| 2026-10-11 00:00 |
22:08:58.93 |
-06:18:23.9 |
HIP 109385 |
11.17 |