| Parameter |
Value |
| Designation |
P/2012 U2 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-12-04T06:27:38.750400Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:26Z |
| Obs used |
36 |
| NEO |
- |
| M1 |
12.100 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-11-14.0000000 |
| e |
0.50656873 |
| q (au) |
3.627785 |
| a (au) |
7.352159 |
| i (deg) |
10.534475 |
| Ω (om, deg) |
186.863069 |
| ω (w, deg) |
229.534876 |
| M (ma, deg) |
358.997883 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.078 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.078 |
| n |
6.000 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.973 |
| 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) |
| 2026-06-01 00:00 |
17:49:38.53 |
-11:34:58.5 |
HIP 87213 |
16.71 |
| 2026-06-01 12:00 |
17:49:28.58 |
-11:34:41.0 |
HIP 87213 |
15.37 |
| 2026-06-02 00:00 |
17:49:18.58 |
-11:34:23.8 |
HIP 87213 |
14.33 |
| 2026-06-02 12:00 |
17:49:08.55 |
-11:34:06.9 |
HIP 87213 |
13.67 |
| 2026-06-03 00:00 |
17:48:58.47 |
-11:33:50.3 |
HIP 87213 |
13.43 |
| 2026-06-03 12:00 |
17:48:48.36 |
-11:33:34.0 |
HIP 87213 |
13.67 |
| 2026-06-04 00:00 |
17:48:38.20 |
-11:33:18.1 |
HIP 87213 |
14.35 |
| 2026-06-04 12:00 |
17:48:28.01 |
-11:33:02.4 |
HIP 87213 |
15.41 |
| 2026-06-05 00:00 |
17:48:17.79 |
-11:32:47.1 |
HIP 87213 |
16.80 |
| 2026-06-05 12:00 |
17:48:07.52 |
-11:32:32.0 |
HIP 87213 |
18.44 |
| 2026-06-06 00:00 |
17:47:57.23 |
-11:32:17.3 |
HIP 87213 |
20.28 |
| 2026-06-06 12:00 |
17:47:46.90 |
-11:32:02.9 |
HIP 87213 |
22.26 |
| 2026-06-07 00:00 |
17:47:36.53 |
-11:31:48.8 |
HIP 87213 |
24.35 |
| 2026-06-07 12:00 |
17:47:26.14 |
-11:31:35.1 |
HIP 87213 |
26.54 |
| 2026-06-08 00:00 |
17:47:15.72 |
-11:31:21.6 |
HIP 87213 |
28.79 |
| 2026-06-08 12:00 |
17:47:05.27 |
-11:31:08.5 |
HIP 87213 |
31.10 |
| 2026-06-09 00:00 |
17:46:54.80 |
-11:30:55.7 |
HIP 87213 |
33.46 |
| 2026-06-09 12:00 |
17:46:44.30 |
-11:30:43.3 |
HIP 87213 |
35.85 |
| 2026-06-10 00:00 |
17:46:33.77 |
-11:30:31.1 |
HIP 87213 |
38.28 |
| 2026-06-10 12:00 |
17:46:23.22 |
-11:30:19.3 |
HIP 87213 |
40.73 |
| 2026-06-11 00:00 |
17:46:12.65 |
-11:30:07.8 |
HIP 86818 |
41.04 |
| 2026-06-11 12:00 |
17:46:02.06 |
-11:29:56.7 |
HIP 86818 |
39.54 |
| 2026-06-12 00:00 |
17:45:51.45 |
-11:29:45.9 |
HIP 86818 |
38.15 |
| 2026-06-12 12:00 |
17:45:40.82 |
-11:29:35.4 |
HIP 86818 |
36.88 |
| 2026-06-13 00:00 |
17:45:30.17 |
-11:29:25.3 |
HIP 86818 |
35.75 |
| 2026-06-13 12:00 |
17:45:19.51 |
-11:29:15.5 |
HIP 86818 |
34.77 |
| 2026-06-14 00:00 |
17:45:08.84 |
-11:29:06.0 |
HIP 86818 |
33.96 |
| 2026-06-14 12:00 |
17:44:58.15 |
-11:28:56.9 |
HIP 86818 |
33.34 |
| 2026-06-15 00:00 |
17:44:47.46 |
-11:28:48.1 |
HIP 86818 |
32.90 |
| 2026-06-15 12:00 |
17:44:36.75 |
-11:28:39.7 |
HIP 86818 |
32.66 |
| 2026-06-16 00:00 |
17:44:26.03 |
-11:28:31.6 |
HIP 86818 |
32.62 |
| 2026-06-16 12:00 |
17:44:15.31 |
-11:28:23.8 |
HIP 86818 |
32.79 |
| 2026-06-17 00:00 |
17:44:04.58 |
-11:28:16.4 |
HIP 86818 |
33.17 |
| 2026-06-17 12:00 |
17:43:53.85 |
-11:28:09.4 |
HIP 86818 |
33.74 |
| 2026-06-18 00:00 |
17:43:43.11 |
-11:28:02.6 |
HIP 86818 |
34.49 |
| 2026-06-18 12:00 |
17:43:32.37 |
-11:27:56.3 |
HIP 86818 |
35.42 |
| 2026-06-19 00:00 |
17:43:21.63 |
-11:27:50.3 |
HIP 86818 |
36.51 |
| 2026-06-19 12:00 |
17:43:10.90 |
-11:27:44.6 |
HIP 86818 |
37.75 |
| 2026-06-20 00:00 |
17:43:00.16 |
-11:27:39.2 |
HIP 86818 |
39.12 |
| 2026-06-20 12:00 |
17:42:49.43 |
-11:27:34.3 |
HIP 86702 |
39.91 |
| 2026-06-21 00:00 |
17:42:38.71 |
-11:27:29.6 |
HIP 86702 |
40.01 |
| 2026-06-21 12:00 |
17:42:27.99 |
-11:27:25.3 |
HIP 86452 |
37.76 |
| 2026-06-22 00:00 |
17:42:17.28 |
-11:27:21.4 |
HIP 86452 |
35.14 |