| Parameter |
Value |
| Designation |
P/2012 C3 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2011-10-05T09:58:58.944000Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:02Z |
| Obs used |
20 |
| NEO |
- |
| M1 |
13.500 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-02-17.0000000 |
| e |
0.62652717 |
| q (au) |
3.624891 |
| a (au) |
9.705904 |
| i (deg) |
9.189868 |
| Ω (om, deg) |
135.441268 |
| ω (w, deg) |
344.851612 |
| M (ma, deg) |
4.386758 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.291 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.291 |
| n |
2.000 |
| gf |
0.971 |
| gb |
-0.507 |
| k |
1.000 |
| δ90 |
9.990 |
| 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 |
20:02:09.34 |
-18:01:07.8 |
HIP 98732 |
20.20 |
| 2026-07-29 12:00 |
20:02:02.64 |
-18:01:31.1 |
HIP 98732 |
21.18 |
| 2026-07-30 00:00 |
20:01:55.94 |
-18:01:54.4 |
HIP 98732 |
22.23 |
| 2026-07-30 12:00 |
20:01:49.26 |
-18:02:17.7 |
HIP 98502 |
21.93 |
| 2026-07-31 00:00 |
20:01:42.59 |
-18:02:41.0 |
HIP 98502 |
20.52 |
| 2026-07-31 12:00 |
20:01:35.92 |
-18:03:04.4 |
HIP 98502 |
19.16 |
| 2026-08-01 00:00 |
20:01:29.27 |
-18:03:27.6 |
HIP 98502 |
17.84 |
| 2026-08-01 12:00 |
20:01:22.64 |
-18:03:50.9 |
HIP 98502 |
16.58 |
| 2026-08-02 00:00 |
20:01:16.01 |
-18:04:14.2 |
HIP 98502 |
15.39 |
| 2026-08-02 12:00 |
20:01:09.40 |
-18:04:37.5 |
HIP 98502 |
14.29 |
| 2026-08-03 00:00 |
20:01:02.80 |
-18:05:00.7 |
HIP 98502 |
13.29 |
| 2026-08-03 12:00 |
20:00:56.22 |
-18:05:23.9 |
HIP 98502 |
12.43 |
| 2026-08-04 00:00 |
20:00:49.66 |
-18:05:47.1 |
HIP 98502 |
11.72 |
| 2026-08-04 12:00 |
20:00:43.11 |
-18:06:10.3 |
HIP 98502 |
11.20 |
| 2026-08-05 00:00 |
20:00:36.58 |
-18:06:33.4 |
HIP 98502 |
10.90 |
| 2026-08-05 12:00 |
20:00:30.06 |
-18:06:56.5 |
HIP 98502 |
10.82 |
| 2026-08-06 00:00 |
20:00:23.57 |
-18:07:19.6 |
HIP 98502 |
10.98 |
| 2026-08-06 12:00 |
20:00:17.09 |
-18:07:42.7 |
HIP 98502 |
11.36 |
| 2026-08-07 00:00 |
20:00:10.64 |
-18:08:05.7 |
HIP 98502 |
11.93 |
| 2026-08-07 12:00 |
20:00:04.20 |
-18:08:28.7 |
HIP 98502 |
12.68 |
| 2026-08-08 00:00 |
19:59:57.79 |
-18:08:51.7 |
HIP 98502 |
13.56 |
| 2026-08-08 12:00 |
19:59:51.39 |
-18:09:14.6 |
HIP 98502 |
14.56 |
| 2026-08-09 00:00 |
19:59:45.02 |
-18:09:37.5 |
HIP 98339 |
13.38 |
| 2026-08-09 12:00 |
19:59:38.67 |
-18:10:00.4 |
HIP 98339 |
11.82 |
| 2026-08-10 00:00 |
19:59:32.35 |
-18:10:23.2 |
HIP 98339 |
10.28 |
| 2026-08-10 12:00 |
19:59:26.05 |
-18:10:45.9 |
HIP 98339 |
8.74 |
| 2026-08-11 00:00 |
19:59:19.77 |
-18:11:08.6 |
HIP 98339 |
7.21 |
| 2026-08-11 12:00 |
19:59:13.52 |
-18:11:31.3 |
HIP 98339 |
5.69 |
| 2026-08-12 00:00 |
19:59:07.30 |
-18:11:53.9 |
HIP 98339 |
4.18 |
| 2026-08-12 12:00 |
19:59:01.10 |
-18:12:16.4 |
HIP 98339 |
2.70 |
| 2026-08-13 00:00 |
19:58:54.93 |
-18:12:38.9 |
HIP 98339 |
1.32 |
| 2026-08-13 12:00 |
19:58:48.79 |
-18:13:01.4 |
HIP 98339 |
0.88 |
| 2026-08-14 00:00 |
19:58:42.68 |
-18:13:23.8 |
HIP 98339 |
2.07 |
| 2026-08-14 12:00 |
19:58:36.60 |
-18:13:46.1 |
HIP 98339 |
3.50 |
| 2026-08-15 00:00 |
19:58:30.55 |
-18:14:08.3 |
HIP 98339 |
4.96 |
| 2026-08-15 12:00 |
19:58:24.53 |
-18:14:30.5 |
HIP 98339 |
6.42 |
| 2026-08-16 00:00 |
19:58:18.54 |
-18:14:52.6 |
HIP 98339 |
7.88 |
| 2026-08-16 12:00 |
19:58:12.58 |
-18:15:14.7 |
HIP 98339 |
9.34 |
| 2026-08-17 00:00 |
19:58:06.66 |
-18:15:36.7 |
HIP 98339 |
10.79 |
| 2026-08-17 12:00 |
19:58:00.77 |
-18:15:58.6 |
HIP 98339 |
12.23 |
| 2026-08-18 00:00 |
19:57:54.91 |
-18:16:20.4 |
HIP 98339 |
13.67 |
| 2026-08-18 12:00 |
19:57:49.09 |
-18:16:42.2 |
HIP 98339 |
15.09 |
| 2026-08-19 00:00 |
19:57:43.30 |
-18:17:03.9 |
HIP 98339 |
16.51 |