| Parameter |
Value |
| Designation |
C/2012 E3 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2011-05-12T22:05:22.326720Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:05Z |
| Obs used |
74 |
| NEO |
- |
| M1 |
9.900 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-03-29.0000000 |
| e |
0.98271491 |
| q (au) |
3.827319 |
| a (au) |
221.423057 |
| i (deg) |
105.658608 |
| Ω (om, deg) |
5.530998 |
| ω (w, deg) |
103.515422 |
| M (ma, deg) |
0.096047 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.440 + 2.856\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.440 |
| n |
2.856 |
| gf |
0.814 |
| gb |
-0.500 |
| k |
0.976 |
| δ90 |
1.000 |
| 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 |
08:40:09.72 |
-46:00:43.7 |
HIP 42601 |
16.08 |
| 2026-03-26 12:00 |
08:40:06.22 |
-45:59:56.9 |
HIP 42601 |
17.06 |
| 2026-03-27 00:00 |
08:40:02.76 |
-45:59:10.0 |
HIP 42601 |
18.04 |
| 2026-03-27 12:00 |
08:39:59.34 |
-45:58:22.8 |
HIP 42601 |
19.02 |
| 2026-03-28 00:00 |
08:39:55.97 |
-45:57:35.5 |
HIP 42601 |
20.00 |
| 2026-03-28 12:00 |
08:39:52.65 |
-45:56:47.9 |
HIP 42521 |
20.09 |
| 2026-03-29 00:00 |
08:39:49.36 |
-45:56:00.3 |
HIP 42521 |
19.40 |
| 2026-03-29 12:00 |
08:39:46.12 |
-45:55:12.4 |
HIP 42521 |
18.74 |
| 2026-03-30 00:00 |
08:39:42.93 |
-45:54:24.4 |
HIP 42521 |
18.10 |
| 2026-03-30 12:00 |
08:39:39.78 |
-45:53:36.2 |
HIP 42521 |
17.49 |
| 2026-03-31 00:00 |
08:39:36.67 |
-45:52:47.8 |
HIP 42521 |
16.90 |
| 2026-03-31 12:00 |
08:39:33.61 |
-45:51:59.3 |
HIP 42521 |
16.35 |
| 2026-04-01 00:00 |
08:39:30.59 |
-45:51:10.7 |
HIP 42521 |
15.83 |
| 2026-04-01 12:00 |
08:39:27.62 |
-45:50:21.9 |
HIP 42521 |
15.35 |
| 2026-04-02 00:00 |
08:39:24.69 |
-45:49:33.0 |
HIP 42521 |
14.91 |
| 2026-04-02 12:00 |
08:39:21.81 |
-45:48:43.9 |
HIP 42521 |
14.52 |
| 2026-04-03 00:00 |
08:39:18.97 |
-45:47:54.7 |
HIP 42521 |
14.17 |
| 2026-04-03 12:00 |
08:39:16.18 |
-45:47:05.3 |
HIP 42521 |
13.87 |
| 2026-04-04 00:00 |
08:39:13.44 |
-45:46:15.9 |
HIP 42521 |
13.63 |
| 2026-04-04 12:00 |
08:39:10.74 |
-45:45:26.3 |
HIP 42521 |
13.44 |
| 2026-04-05 00:00 |
08:39:08.08 |
-45:44:36.6 |
HIP 42521 |
13.31 |
| 2026-04-05 12:00 |
08:39:05.47 |
-45:43:46.8 |
HIP 42521 |
13.24 |
| 2026-04-06 00:00 |
08:39:02.91 |
-45:42:56.9 |
HIP 42521 |
13.23 |
| 2026-04-06 12:00 |
08:39:00.39 |
-45:42:06.8 |
HIP 42521 |
13.28 |
| 2026-04-07 00:00 |
08:38:57.92 |
-45:41:16.7 |
HIP 42521 |
13.38 |
| 2026-04-07 12:00 |
08:38:55.49 |
-45:40:26.5 |
HIP 42521 |
13.55 |
| 2026-04-08 00:00 |
08:38:53.11 |
-45:39:36.1 |
HIP 42521 |
13.77 |
| 2026-04-08 12:00 |
08:38:50.78 |
-45:38:45.7 |
HIP 42521 |
14.03 |
| 2026-04-09 00:00 |
08:38:48.50 |
-45:37:55.2 |
HIP 42521 |
14.35 |
| 2026-04-09 12:00 |
08:38:46.26 |
-45:37:04.7 |
HIP 42521 |
14.71 |
| 2026-04-10 00:00 |
08:38:44.06 |
-45:36:14.0 |
HIP 42521 |
15.11 |
| 2026-04-10 12:00 |
08:38:41.92 |
-45:35:23.3 |
HIP 42521 |
15.55 |
| 2026-04-11 00:00 |
08:38:39.82 |
-45:34:32.5 |
HIP 42357 |
15.20 |
| 2026-04-11 12:00 |
08:38:37.76 |
-45:33:41.6 |
HIP 42357 |
14.28 |
| 2026-04-12 00:00 |
08:38:35.76 |
-45:32:50.7 |
HIP 42357 |
13.36 |
| 2026-04-12 12:00 |
08:38:33.80 |
-45:31:59.8 |
HIP 42357 |
12.45 |
| 2026-04-13 00:00 |
08:38:31.89 |
-45:31:08.7 |
HIP 42357 |
11.54 |
| 2026-04-13 12:00 |
08:38:30.02 |
-45:30:17.7 |
HIP 42357 |
10.62 |
| 2026-04-14 00:00 |
08:38:28.21 |
-45:29:26.6 |
HIP 42357 |
9.71 |
| 2026-04-14 12:00 |
08:38:26.44 |
-45:28:35.4 |
HIP 42357 |
8.81 |
| 2026-04-15 00:00 |
08:38:24.71 |
-45:27:44.2 |
HIP 42357 |
7.90 |
| 2026-04-15 12:00 |
08:38:23.04 |
-45:26:53.0 |
HIP 42357 |
7.00 |
| 2026-04-16 00:00 |
08:38:21.41 |
-45:26:01.8 |
HIP 42357 |
6.10 |