| Parameter |
Value |
| Designation |
C/2016 P4 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2016-10-15T10:34:01.790400Z |
| Orbit solution date (soln_date, UTC) |
2022-06-20T23:12:32Z |
| Obs used |
45 |
| NEO |
- |
| M1 |
7.600 |
| K1 |
14.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2016-09-18.0000000 |
| e |
0.98170392 |
| q (au) |
5.891877 |
| a (au) |
322.029424 |
| i (deg) |
29.927110 |
| Ω (om, deg) |
320.784742 |
| ω (w, deg) |
355.902036 |
| M (ma, deg) |
359.995320 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.699 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.699 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.617 |
| k |
0.800 |
| 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) |
| 2026-05-12 00:00 |
04:37:38.51 |
+48:41:23.5 |
HIP 21659 |
15.53 |
| 2026-05-12 12:00 |
04:37:47.51 |
+48:41:20.0 |
HIP 21659 |
14.20 |
| 2026-05-13 00:00 |
04:37:56.52 |
+48:41:16.8 |
HIP 21659 |
12.91 |
| 2026-05-13 12:00 |
04:38:05.56 |
+48:41:13.9 |
HIP 21659 |
11.67 |
| 2026-05-14 00:00 |
04:38:14.61 |
+48:41:11.3 |
HIP 21659 |
10.50 |
| 2026-05-14 12:00 |
04:38:23.68 |
+48:41:08.9 |
HIP 21659 |
9.42 |
| 2026-05-15 00:00 |
04:38:32.76 |
+48:41:06.8 |
HIP 21659 |
8.48 |
| 2026-05-15 12:00 |
04:38:41.87 |
+48:41:05.0 |
HIP 21659 |
7.71 |
| 2026-05-16 00:00 |
04:38:50.98 |
+48:41:03.5 |
HIP 21659 |
7.19 |
| 2026-05-16 12:00 |
04:39:00.12 |
+48:41:02.2 |
HIP 21659 |
6.96 |
| 2026-05-17 00:00 |
04:39:09.27 |
+48:41:01.3 |
HIP 21659 |
7.06 |
| 2026-05-17 12:00 |
04:39:18.43 |
+48:41:00.6 |
HIP 21659 |
7.48 |
| 2026-05-18 00:00 |
04:39:27.61 |
+48:41:00.1 |
HIP 21659 |
8.17 |
| 2026-05-18 12:00 |
04:39:36.80 |
+48:41:00.0 |
HIP 21659 |
9.06 |
| 2026-05-19 00:00 |
04:39:46.00 |
+48:41:00.1 |
HIP 21659 |
10.11 |
| 2026-05-19 12:00 |
04:39:55.22 |
+48:41:00.5 |
HIP 21800 |
10.82 |
| 2026-05-20 00:00 |
04:40:04.45 |
+48:41:01.2 |
HIP 21800 |
9.31 |
| 2026-05-20 12:00 |
04:40:13.69 |
+48:41:02.1 |
HIP 21800 |
7.79 |
| 2026-05-21 00:00 |
04:40:22.94 |
+48:41:03.4 |
HIP 21800 |
6.28 |
| 2026-05-21 12:00 |
04:40:32.20 |
+48:41:04.8 |
HIP 21800 |
4.78 |
| 2026-05-22 00:00 |
04:40:41.47 |
+48:41:06.6 |
HIP 21800 |
3.31 |
| 2026-05-22 12:00 |
04:40:50.75 |
+48:41:08.6 |
HIP 21800 |
1.93 |
| 2026-05-23 00:00 |
04:41:00.04 |
+48:41:10.9 |
HIP 21800 |
1.09 |
| 2026-05-23 12:00 |
04:41:09.34 |
+48:41:13.5 |
HIP 21800 |
1.84 |
| 2026-05-24 00:00 |
04:41:18.64 |
+48:41:16.3 |
HIP 21800 |
3.21 |
| 2026-05-24 12:00 |
04:41:27.95 |
+48:41:19.4 |
HIP 21800 |
4.69 |
| 2026-05-25 00:00 |
04:41:37.27 |
+48:41:22.8 |
HIP 21800 |
6.20 |
| 2026-05-25 12:00 |
04:41:46.60 |
+48:41:26.4 |
HIP 21800 |
7.72 |
| 2026-05-26 00:00 |
04:41:55.94 |
+48:41:30.3 |
HIP 21800 |
9.25 |
| 2026-05-26 12:00 |
04:42:05.27 |
+48:41:34.4 |
HIP 21800 |
10.79 |
| 2026-05-27 00:00 |
04:42:14.62 |
+48:41:38.8 |
HIP 21800 |
12.33 |
| 2026-05-27 12:00 |
04:42:23.97 |
+48:41:43.5 |
HIP 21800 |
13.87 |
| 2026-05-28 00:00 |
04:42:33.32 |
+48:41:48.5 |
HIP 21800 |
15.41 |
| 2026-05-28 12:00 |
04:42:42.68 |
+48:41:53.7 |
HIP 21800 |
16.96 |
| 2026-05-29 00:00 |
04:42:52.04 |
+48:41:59.1 |
HIP 21800 |
18.50 |
| 2026-05-29 12:00 |
04:43:01.41 |
+48:42:04.8 |
HIP 21800 |
20.05 |
| 2026-05-30 00:00 |
04:43:10.78 |
+48:42:10.8 |
HIP 21800 |
21.60 |
| 2026-05-30 12:00 |
04:43:20.15 |
+48:42:17.0 |
HIP 21800 |
23.15 |
| 2026-05-31 00:00 |
04:43:29.52 |
+48:42:23.5 |
HIP 21800 |
24.70 |
| 2026-05-31 12:00 |
04:43:38.89 |
+48:42:30.3 |
HIP 21800 |
26.25 |
| 2026-06-01 00:00 |
04:43:48.27 |
+48:42:37.3 |
HIP 21800 |
27.80 |
| 2026-06-01 12:00 |
04:43:57.64 |
+48:42:44.5 |
HIP 21800 |
29.35 |
| 2026-06-02 00:00 |
04:44:07.02 |
+48:42:52.0 |
HIP 21800 |
30.90 |