| Parameter |
Value |
| Designation |
C/2012 S3 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-08-31T03:14:37.167360Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:22Z |
| Obs used |
730 |
| NEO |
- |
| M1 |
13.700 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-05-22.0000000 |
| e |
1.00070829 |
| q (au) |
2.308066 |
| a (au) |
-3258.643490 |
| i (deg) |
112.930798 |
| Ω (om, deg) |
121.305818 |
| ω (w, deg) |
183.752733 |
| M (ma, deg) |
-0.000536 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.451 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.451 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.998 |
| 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) |
| 2026-07-29 00:00 |
08:34:01.36 |
-07:55:30.5 |
HIP 41976 |
9.63 |
| 2026-07-29 12:00 |
08:34:05.14 |
-07:55:39.3 |
HIP 41976 |
10.58 |
| 2026-07-30 00:00 |
08:34:08.93 |
-07:55:48.4 |
HIP 41976 |
11.53 |
| 2026-07-30 12:00 |
08:34:12.71 |
-07:55:57.7 |
HIP 41976 |
12.47 |
| 2026-07-31 00:00 |
08:34:16.49 |
-07:56:07.3 |
HIP 41976 |
13.42 |
| 2026-07-31 12:00 |
08:34:20.28 |
-07:56:17.0 |
HIP 41976 |
14.37 |
| 2026-08-01 00:00 |
08:34:24.06 |
-07:56:27.0 |
HIP 41976 |
15.32 |
| 2026-08-01 12:00 |
08:34:27.83 |
-07:56:37.1 |
HIP 42146 |
15.13 |
| 2026-08-02 00:00 |
08:34:31.61 |
-07:56:47.5 |
HIP 42146 |
14.18 |
| 2026-08-02 12:00 |
08:34:35.38 |
-07:56:58.1 |
HIP 42146 |
13.23 |
| 2026-08-03 00:00 |
08:34:39.15 |
-07:57:08.9 |
HIP 42146 |
12.28 |
| 2026-08-03 12:00 |
08:34:42.92 |
-07:57:19.9 |
HIP 42146 |
11.33 |
| 2026-08-04 00:00 |
08:34:46.69 |
-07:57:31.2 |
HIP 42146 |
10.38 |
| 2026-08-04 12:00 |
08:34:50.45 |
-07:57:42.6 |
HIP 42146 |
9.43 |
| 2026-08-05 00:00 |
08:34:54.21 |
-07:57:54.2 |
HIP 42146 |
8.48 |
| 2026-08-05 12:00 |
08:34:57.96 |
-07:58:06.1 |
HIP 42146 |
7.54 |
| 2026-08-06 00:00 |
08:35:01.71 |
-07:58:18.2 |
HIP 42146 |
6.59 |
| 2026-08-06 12:00 |
08:35:05.46 |
-07:58:30.4 |
HIP 42146 |
5.65 |
| 2026-08-07 00:00 |
08:35:09.20 |
-07:58:42.9 |
HIP 42146 |
4.71 |
| 2026-08-07 12:00 |
08:35:12.94 |
-07:58:55.6 |
HIP 42146 |
3.78 |
| 2026-08-08 00:00 |
08:35:16.67 |
-07:59:08.5 |
HIP 42146 |
2.86 |
| 2026-08-08 12:00 |
08:35:20.40 |
-07:59:21.6 |
HIP 42146 |
1.98 |
| 2026-08-09 00:00 |
08:35:24.12 |
-07:59:34.8 |
HIP 42146 |
1.20 |
| 2026-08-09 12:00 |
08:35:27.84 |
-07:59:48.3 |
HIP 42146 |
0.87 |
| 2026-08-10 00:00 |
08:35:31.55 |
-08:00:02.0 |
HIP 42146 |
1.37 |
| 2026-08-10 12:00 |
08:35:35.25 |
-08:00:15.9 |
HIP 42146 |
2.19 |
| 2026-08-11 00:00 |
08:35:38.95 |
-08:00:30.0 |
HIP 42146 |
3.08 |
| 2026-08-11 12:00 |
08:35:42.64 |
-08:00:44.2 |
HIP 42146 |
4.00 |
| 2026-08-12 00:00 |
08:35:46.33 |
-08:00:58.7 |
HIP 42146 |
4.93 |
| 2026-08-12 12:00 |
08:35:50.00 |
-08:01:13.4 |
HIP 42146 |
5.86 |
| 2026-08-13 00:00 |
08:35:53.67 |
-08:01:28.2 |
HIP 42146 |
6.79 |
| 2026-08-13 12:00 |
08:35:57.33 |
-08:01:43.3 |
HIP 42146 |
7.73 |
| 2026-08-14 00:00 |
08:36:00.99 |
-08:01:58.5 |
HIP 42146 |
8.66 |
| 2026-08-14 12:00 |
08:36:04.63 |
-08:02:13.9 |
HIP 42146 |
9.60 |
| 2026-08-15 00:00 |
08:36:08.27 |
-08:02:29.5 |
HIP 42146 |
10.53 |
| 2026-08-15 12:00 |
08:36:11.90 |
-08:02:45.3 |
HIP 42146 |
11.47 |
| 2026-08-16 00:00 |
08:36:15.52 |
-08:03:01.3 |
HIP 42146 |
12.40 |
| 2026-08-16 12:00 |
08:36:19.13 |
-08:03:17.4 |
HIP 42146 |
13.33 |
| 2026-08-17 00:00 |
08:36:22.73 |
-08:03:33.7 |
HIP 42146 |
14.26 |
| 2026-08-17 12:00 |
08:36:26.31 |
-08:03:50.3 |
HIP 42146 |
15.19 |
| 2026-08-18 00:00 |
08:36:29.89 |
-08:04:06.9 |
HIP 42146 |
16.12 |
| 2026-08-18 12:00 |
08:36:33.46 |
-08:04:23.8 |
HIP 42146 |
17.05 |
| 2026-08-19 00:00 |
08:36:37.02 |
-08:04:40.8 |
HIP 42260 |
16.98 |