| Parameter |
Value |
| Designation |
C/2013 G8 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-11-14T23:30:02.741760Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:34Z |
| Obs used |
147 |
| NEO |
- |
| M1 |
7.700 |
| K1 |
11.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-09-14.0000000 |
| e |
0.99844886 |
| q (au) |
5.141176 |
| a (au) |
3314.451067 |
| i (deg) |
27.615046 |
| Ω (om, deg) |
241.021944 |
| ω (w, deg) |
80.168493 |
| M (ma, deg) |
359.999680 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.524 + 2.882\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.524 |
| n |
2.882 |
| gf |
0.988 |
| gb |
-0.652 |
| 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 |
05:54:13.92 |
+10:49:21.0 |
HIP 27900 |
14.17 |
| 2026-09-20 12:00 |
05:54:14.44 |
+10:49:03.3 |
HIP 27900 |
13.87 |
| 2026-09-21 00:00 |
05:54:14.93 |
+10:48:45.6 |
HIP 27900 |
13.58 |
| 2026-09-21 12:00 |
05:54:15.37 |
+10:48:27.8 |
HIP 27900 |
13.29 |
| 2026-09-22 00:00 |
05:54:15.78 |
+10:48:10.1 |
HIP 27900 |
13.00 |
| 2026-09-22 12:00 |
05:54:16.15 |
+10:47:52.3 |
HIP 27900 |
12.71 |
| 2026-09-23 00:00 |
05:54:16.48 |
+10:47:34.5 |
HIP 27900 |
12.41 |
| 2026-09-23 12:00 |
05:54:16.77 |
+10:47:16.8 |
HIP 27900 |
12.12 |
| 2026-09-24 00:00 |
05:54:17.02 |
+10:46:59.0 |
HIP 27900 |
11.83 |
| 2026-09-24 12:00 |
05:54:17.24 |
+10:46:41.2 |
HIP 27900 |
11.54 |
| 2026-09-25 00:00 |
05:54:17.41 |
+10:46:23.3 |
HIP 27900 |
11.25 |
| 2026-09-25 12:00 |
05:54:17.55 |
+10:46:05.5 |
HIP 27900 |
10.96 |
| 2026-09-26 00:00 |
05:54:17.65 |
+10:45:47.7 |
HIP 27900 |
10.66 |
| 2026-09-26 12:00 |
05:54:17.71 |
+10:45:29.9 |
HIP 27900 |
10.37 |
| 2026-09-27 00:00 |
05:54:17.73 |
+10:45:12.0 |
HIP 27900 |
10.07 |
| 2026-09-27 12:00 |
05:54:17.72 |
+10:44:54.2 |
HIP 27900 |
9.78 |
| 2026-09-28 00:00 |
05:54:17.66 |
+10:44:36.3 |
HIP 27900 |
9.48 |
| 2026-09-28 12:00 |
05:54:17.57 |
+10:44:18.5 |
HIP 27900 |
9.18 |
| 2026-09-29 00:00 |
05:54:17.44 |
+10:44:00.6 |
HIP 27900 |
8.88 |
| 2026-09-29 12:00 |
05:54:17.27 |
+10:43:42.8 |
HIP 27900 |
8.58 |
| 2026-09-30 00:00 |
05:54:17.06 |
+10:43:25.0 |
HIP 27900 |
8.28 |
| 2026-09-30 12:00 |
05:54:16.81 |
+10:43:07.1 |
HIP 27900 |
7.98 |
| 2026-10-01 00:00 |
05:54:16.53 |
+10:42:49.3 |
HIP 27900 |
7.68 |
| 2026-10-01 12:00 |
05:54:16.20 |
+10:42:31.4 |
HIP 27900 |
7.37 |
| 2026-10-02 00:00 |
05:54:15.84 |
+10:42:13.6 |
HIP 27900 |
7.07 |
| 2026-10-02 12:00 |
05:54:15.44 |
+10:41:55.8 |
HIP 27900 |
6.76 |
| 2026-10-03 00:00 |
05:54:15.00 |
+10:41:38.0 |
HIP 27900 |
6.46 |
| 2026-10-03 12:00 |
05:54:14.52 |
+10:41:20.2 |
HIP 27900 |
6.16 |
| 2026-10-04 00:00 |
05:54:14.00 |
+10:41:02.4 |
HIP 27900 |
5.86 |
| 2026-10-04 12:00 |
05:54:13.45 |
+10:40:44.6 |
HIP 27900 |
5.56 |
| 2026-10-05 00:00 |
05:54:12.85 |
+10:40:26.8 |
HIP 27900 |
5.26 |
| 2026-10-05 12:00 |
05:54:12.22 |
+10:40:09.1 |
HIP 27900 |
4.97 |
| 2026-10-06 00:00 |
05:54:11.55 |
+10:39:51.3 |
HIP 27900 |
4.69 |
| 2026-10-06 12:00 |
05:54:10.84 |
+10:39:33.6 |
HIP 27900 |
4.42 |
| 2026-10-07 00:00 |
05:54:10.09 |
+10:39:15.9 |
HIP 27900 |
4.16 |
| 2026-10-07 12:00 |
05:54:09.31 |
+10:38:58.2 |
HIP 27900 |
3.91 |
| 2026-10-08 00:00 |
05:54:08.48 |
+10:38:40.5 |
HIP 27900 |
3.69 |
| 2026-10-08 12:00 |
05:54:07.62 |
+10:38:22.9 |
HIP 27900 |
3.49 |
| 2026-10-09 00:00 |
05:54:06.72 |
+10:38:05.3 |
HIP 27900 |
3.33 |
| 2026-10-09 12:00 |
05:54:05.78 |
+10:37:47.7 |
HIP 27900 |
3.20 |
| 2026-10-10 00:00 |
05:54:04.80 |
+10:37:30.1 |
HIP 27900 |
3.13 |
| 2026-10-10 12:00 |
05:54:03.79 |
+10:37:12.5 |
HIP 27900 |
3.10 |
| 2026-10-11 00:00 |
05:54:02.73 |
+10:36:55.0 |
HIP 27900 |
3.13 |