| Parameter |
Value |
| Designation |
P/2015 P4 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2016-01-19T00:45:47.321280Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:13Z |
| Obs used |
80 |
| NEO |
- |
| M1 |
6.500 |
| K1 |
28.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-09-21.0000000 |
| e |
0.58423891 |
| q (au) |
2.525162 |
| a (au) |
6.073589 |
| i (deg) |
8.713757 |
| Ω (om, deg) |
104.746924 |
| ω (w, deg) |
280.816811 |
| M (ma, deg) |
352.096266 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.240 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.240 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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) |
| 2026-03-26 00:00 |
15:32:39.05 |
-11:01:09.0 |
HIP 76020 |
20.12 |
| 2026-03-26 12:00 |
15:32:33.23 |
-11:00:28.7 |
HIP 76020 |
19.56 |
| 2026-03-27 00:00 |
15:32:27.31 |
-10:59:48.1 |
HIP 76020 |
19.11 |
| 2026-03-27 12:00 |
15:32:21.28 |
-10:59:07.3 |
HIP 76020 |
18.77 |
| 2026-03-28 00:00 |
15:32:15.15 |
-10:58:26.2 |
HIP 76020 |
18.56 |
| 2026-03-28 12:00 |
15:32:08.91 |
-10:57:44.9 |
HIP 76020 |
18.49 |
| 2026-03-29 00:00 |
15:32:02.57 |
-10:57:03.4 |
HIP 76020 |
18.56 |
| 2026-03-29 12:00 |
15:31:56.12 |
-10:56:21.6 |
HIP 76020 |
18.79 |
| 2026-03-30 00:00 |
15:31:49.57 |
-10:55:39.6 |
HIP 76020 |
19.17 |
| 2026-03-30 12:00 |
15:31:42.91 |
-10:54:57.4 |
HIP 76020 |
19.70 |
| 2026-03-31 00:00 |
15:31:36.16 |
-10:54:15.0 |
HIP 76020 |
20.38 |
| 2026-03-31 12:00 |
15:31:29.30 |
-10:53:32.3 |
HIP 76020 |
21.20 |
| 2026-04-01 00:00 |
15:31:22.34 |
-10:52:49.5 |
HIP 76020 |
22.14 |
| 2026-04-01 12:00 |
15:31:15.29 |
-10:52:06.4 |
HIP 76020 |
23.20 |
| 2026-04-02 00:00 |
15:31:08.13 |
-10:51:23.1 |
HIP 76020 |
24.38 |
| 2026-04-02 12:00 |
15:31:00.87 |
-10:50:39.7 |
HIP 76020 |
25.65 |
| 2026-04-03 00:00 |
15:30:53.52 |
-10:49:56.0 |
HIP 76020 |
27.01 |
| 2026-04-03 12:00 |
15:30:46.07 |
-10:49:12.2 |
HIP 76020 |
28.45 |
| 2026-04-04 00:00 |
15:30:38.52 |
-10:48:28.1 |
HIP 76020 |
29.97 |
| 2026-04-04 12:00 |
15:30:30.88 |
-10:47:43.9 |
HIP 76020 |
31.55 |
| 2026-04-05 00:00 |
15:30:23.14 |
-10:46:59.5 |
HIP 76020 |
33.20 |
| 2026-04-05 12:00 |
15:30:15.30 |
-10:46:15.0 |
HIP 76020 |
34.90 |
| 2026-04-06 00:00 |
15:30:07.38 |
-10:45:30.2 |
HIP 76020 |
36.66 |
| 2026-04-06 12:00 |
15:29:59.36 |
-10:44:45.3 |
HIP 76020 |
38.47 |
| 2026-04-07 00:00 |
15:29:51.25 |
-10:44:00.3 |
HIP 75663 |
37.23 |
| 2026-04-07 12:00 |
15:29:43.05 |
-10:43:15.1 |
HIP 75663 |
35.67 |
| 2026-04-08 00:00 |
15:29:34.75 |
-10:42:29.7 |
HIP 75663 |
34.15 |
| 2026-04-08 12:00 |
15:29:26.37 |
-10:41:44.2 |
HIP 75663 |
32.69 |
| 2026-04-09 00:00 |
15:29:17.90 |
-10:40:58.6 |
HIP 75663 |
31.29 |
| 2026-04-09 12:00 |
15:29:09.34 |
-10:40:12.8 |
HIP 75663 |
29.98 |
| 2026-04-10 00:00 |
15:29:00.70 |
-10:39:26.9 |
HIP 75663 |
28.77 |
| 2026-04-10 12:00 |
15:28:51.97 |
-10:38:40.9 |
HIP 75663 |
27.67 |
| 2026-04-11 00:00 |
15:28:43.15 |
-10:37:54.8 |
HIP 75663 |
26.71 |
| 2026-04-11 12:00 |
15:28:34.25 |
-10:37:08.5 |
HIP 75663 |
25.91 |
| 2026-04-12 00:00 |
15:28:25.27 |
-10:36:22.2 |
HIP 75663 |
25.28 |
| 2026-04-12 12:00 |
15:28:16.20 |
-10:35:35.7 |
HIP 75663 |
24.85 |
| 2026-04-13 00:00 |
15:28:07.06 |
-10:34:49.1 |
HIP 75663 |
24.64 |
| 2026-04-13 12:00 |
15:27:57.83 |
-10:34:02.5 |
HIP 75663 |
24.65 |
| 2026-04-14 00:00 |
15:27:48.52 |
-10:33:15.8 |
HIP 75663 |
24.89 |
| 2026-04-14 12:00 |
15:27:39.14 |
-10:32:28.9 |
HIP 75663 |
25.36 |
| 2026-04-15 00:00 |
15:27:29.68 |
-10:31:42.1 |
HIP 75663 |
26.05 |
| 2026-04-15 12:00 |
15:27:20.14 |
-10:30:55.1 |
HIP 75663 |
26.94 |
| 2026-04-16 00:00 |
15:27:10.53 |
-10:30:08.1 |
HIP 75663 |
28.04 |