| Parameter |
Value |
| Designation |
P/2013 G4 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2013-02-09T16:30:18.377280Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:32Z |
| Obs used |
41 |
| NEO |
- |
| M1 |
15.100 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-04-25.0000000 |
| e |
0.41041543 |
| q (au) |
2.613194 |
| a (au) |
4.432263 |
| i (deg) |
5.925606 |
| Ω (om, deg) |
339.772839 |
| ω (w, deg) |
214.390935 |
| M (ma, deg) |
7.849220 |
Magnitude
Scatter + Global Linear
$$
M_a = (19.266 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
19.266 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.647 |
| 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) |
| 2026-09-20 00:00 |
00:25:33.77 |
+06:13:55.2 |
HIP 2083 |
13.82 |
| 2026-09-20 12:00 |
00:25:19.37 |
+06:12:36.6 |
HIP 2083 |
16.22 |
| 2026-09-21 00:00 |
00:25:04.95 |
+06:11:17.6 |
HIP 2083 |
19.09 |
| 2026-09-21 12:00 |
00:24:50.49 |
+06:09:58.1 |
HIP 2083 |
22.26 |
| 2026-09-22 00:00 |
00:24:36.00 |
+06:08:38.3 |
HIP 1847 |
22.96 |
| 2026-09-22 12:00 |
00:24:21.48 |
+06:07:18.1 |
HIP 1847 |
19.25 |
| 2026-09-23 00:00 |
00:24:06.94 |
+06:05:57.6 |
HIP 1847 |
15.62 |
| 2026-09-23 12:00 |
00:23:52.37 |
+06:04:36.7 |
HIP 1847 |
12.10 |
| 2026-09-24 00:00 |
00:23:37.78 |
+06:03:15.4 |
HIP 1847 |
8.88 |
| 2026-09-24 12:00 |
00:23:23.17 |
+06:01:53.8 |
HIP 1847 |
6.41 |
| 2026-09-25 00:00 |
00:23:08.54 |
+06:00:31.9 |
HIP 1847 |
5.79 |
| 2026-09-25 12:00 |
00:22:53.90 |
+05:59:09.7 |
HIP 1847 |
7.49 |
| 2026-09-26 00:00 |
00:22:39.25 |
+05:57:47.2 |
HIP 1847 |
10.44 |
| 2026-09-26 12:00 |
00:22:24.58 |
+05:56:24.4 |
HIP 1847 |
13.86 |
| 2026-09-27 00:00 |
00:22:09.90 |
+05:55:01.3 |
HIP 1847 |
17.49 |
| 2026-09-27 12:00 |
00:21:55.21 |
+05:53:38.0 |
HIP 1847 |
21.22 |
| 2026-09-28 00:00 |
00:21:40.52 |
+05:52:14.4 |
HIP 1847 |
25.01 |
| 2026-09-28 12:00 |
00:21:25.83 |
+05:50:50.6 |
HIP 1847 |
28.83 |
| 2026-09-29 00:00 |
00:21:11.13 |
+05:49:26.6 |
HIP 1566 |
25.64 |
| 2026-09-29 12:00 |
00:20:56.44 |
+05:48:02.4 |
HIP 1566 |
21.83 |
| 2026-09-30 00:00 |
00:20:41.75 |
+05:46:38.0 |
HIP 1566 |
18.07 |
| 2026-09-30 12:00 |
00:20:27.06 |
+05:45:13.4 |
HIP 1566 |
14.40 |
| 2026-10-01 00:00 |
00:20:12.38 |
+05:43:48.6 |
HIP 1566 |
10.89 |
| 2026-10-01 12:00 |
00:19:57.70 |
+05:42:23.7 |
HIP 1566 |
7.79 |
| 2026-10-02 00:00 |
00:19:43.04 |
+05:40:58.6 |
HIP 1566 |
5.78 |
| 2026-10-02 12:00 |
00:19:28.40 |
+05:39:33.4 |
HIP 1566 |
6.07 |
| 2026-10-03 00:00 |
00:19:13.76 |
+05:38:08.1 |
HIP 1566 |
8.42 |
| 2026-10-03 12:00 |
00:18:59.15 |
+05:36:42.7 |
HIP 1566 |
11.63 |
| 2026-10-04 00:00 |
00:18:44.55 |
+05:35:17.2 |
HIP 1566 |
15.17 |
| 2026-10-04 12:00 |
00:18:29.98 |
+05:33:51.6 |
HIP 1566 |
18.85 |
| 2026-10-05 00:00 |
00:18:15.43 |
+05:32:26.0 |
HIP 1566 |
22.60 |
| 2026-10-05 12:00 |
00:18:00.91 |
+05:31:00.3 |
HIP 1566 |
26.39 |
| 2026-10-06 00:00 |
00:17:46.41 |
+05:29:34.6 |
HIP 1566 |
30.19 |
| 2026-10-06 12:00 |
00:17:31.95 |
+05:28:08.8 |
HIP 1432 |
31.33 |
| 2026-10-07 00:00 |
00:17:17.52 |
+05:26:43.1 |
HIP 1432 |
30.71 |
| 2026-10-07 12:00 |
00:17:03.12 |
+05:25:17.4 |
HIP 1432 |
30.57 |
| 2026-10-08 00:00 |
00:16:48.76 |
+05:23:51.7 |
HIP 1199 |
29.38 |
| 2026-10-08 12:00 |
00:16:34.44 |
+05:22:26.0 |
HIP 1199 |
26.79 |
| 2026-10-09 00:00 |
00:16:20.16 |
+05:21:00.5 |
HIP 1199 |
24.54 |
| 2026-10-09 12:00 |
00:16:05.93 |
+05:19:34.9 |
HIP 1199 |
22.72 |
| 2026-10-10 00:00 |
00:15:51.74 |
+05:18:09.5 |
HIP 1199 |
21.44 |
| 2026-10-10 12:00 |
00:15:37.60 |
+05:16:44.2 |
HIP 1199 |
20.79 |
| 2026-10-11 00:00 |
00:15:23.51 |
+05:15:19.0 |
HIP 1199 |
20.82 |