| Parameter |
Value |
| Designation |
C/2012 U1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2014-07-04T17:20:39.560640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:25Z |
| Obs used |
172 |
| NEO |
- |
| M1 |
8.300 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-12-31.0000000 |
| e |
0.99956488 |
| q (au) |
5.263903 |
| a (au) |
12097.722849 |
| i (deg) |
56.339020 |
| Ω (om, deg) |
26.982573 |
| ω (w, deg) |
70.049903 |
| M (ma, deg) |
359.999862 |
Magnitude
Scatter + Global Linear
$$
M_a = (3.230 + 5.910\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
3.230 |
| n |
5.910 |
| gf |
1.000 |
| gb |
-0.501 |
| 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 |
13:45:38.97 |
-25:10:38.8 |
HIP 67071 |
22.84 |
| 2026-07-29 12:00 |
13:45:39.81 |
-25:10:34.2 |
HIP 67071 |
23.00 |
| 2026-07-30 00:00 |
13:45:40.68 |
-25:10:29.8 |
HIP 67071 |
23.17 |
| 2026-07-30 12:00 |
13:45:41.59 |
-25:10:25.6 |
HIP 67071 |
23.34 |
| 2026-07-31 00:00 |
13:45:42.54 |
-25:10:21.7 |
HIP 67071 |
23.51 |
| 2026-07-31 12:00 |
13:45:43.52 |
-25:10:17.9 |
HIP 67071 |
23.68 |
| 2026-08-01 00:00 |
13:45:44.55 |
-25:10:14.4 |
HIP 67071 |
23.86 |
| 2026-08-01 12:00 |
13:45:45.62 |
-25:10:11.2 |
HIP 67071 |
24.04 |
| 2026-08-02 00:00 |
13:45:46.72 |
-25:10:08.1 |
HIP 67071 |
24.22 |
| 2026-08-02 12:00 |
13:45:47.86 |
-25:10:05.3 |
HIP 67071 |
24.41 |
| 2026-08-03 00:00 |
13:45:49.04 |
-25:10:02.7 |
HIP 67071 |
24.60 |
| 2026-08-03 12:00 |
13:45:50.26 |
-25:10:00.3 |
HIP 67071 |
24.79 |
| 2026-08-04 00:00 |
13:45:51.52 |
-25:09:58.1 |
HIP 67071 |
24.99 |
| 2026-08-04 12:00 |
13:45:52.81 |
-25:09:56.2 |
HIP 67071 |
25.19 |
| 2026-08-05 00:00 |
13:45:54.14 |
-25:09:54.5 |
HIP 67071 |
25.40 |
| 2026-08-05 12:00 |
13:45:55.52 |
-25:09:53.1 |
HIP 67071 |
25.60 |
| 2026-08-06 00:00 |
13:45:56.92 |
-25:09:51.8 |
HIP 67071 |
25.82 |
| 2026-08-06 12:00 |
13:45:58.37 |
-25:09:50.8 |
HIP 67071 |
26.04 |
| 2026-08-07 00:00 |
13:45:59.85 |
-25:09:50.1 |
HIP 67071 |
26.26 |
| 2026-08-07 12:00 |
13:46:01.37 |
-25:09:49.5 |
HIP 67071 |
26.49 |
| 2026-08-08 00:00 |
13:46:02.93 |
-25:09:49.2 |
HIP 67071 |
26.72 |
| 2026-08-08 12:00 |
13:46:04.53 |
-25:09:49.2 |
HIP 67071 |
26.96 |
| 2026-08-09 00:00 |
13:46:06.16 |
-25:09:49.3 |
HIP 67071 |
27.20 |
| 2026-08-09 12:00 |
13:46:07.83 |
-25:09:49.7 |
HIP 67071 |
27.45 |
| 2026-08-10 00:00 |
13:46:09.54 |
-25:09:50.3 |
HIP 67071 |
27.70 |
| 2026-08-10 12:00 |
13:46:11.28 |
-25:09:51.2 |
HIP 67071 |
27.96 |
| 2026-08-11 00:00 |
13:46:13.06 |
-25:09:52.3 |
HIP 67071 |
28.23 |
| 2026-08-11 12:00 |
13:46:14.88 |
-25:09:53.6 |
HIP 67071 |
28.50 |
| 2026-08-12 00:00 |
13:46:16.73 |
-25:09:55.2 |
HIP 67071 |
28.78 |
| 2026-08-12 12:00 |
13:46:18.62 |
-25:09:57.0 |
HIP 67071 |
29.07 |
| 2026-08-13 00:00 |
13:46:20.55 |
-25:09:59.0 |
HIP 67071 |
29.36 |
| 2026-08-13 12:00 |
13:46:22.51 |
-25:10:01.3 |
HIP 67071 |
29.66 |
| 2026-08-14 00:00 |
13:46:24.51 |
-25:10:03.8 |
HIP 67071 |
29.97 |
| 2026-08-14 12:00 |
13:46:26.54 |
-25:10:06.6 |
HIP 67071 |
30.28 |
| 2026-08-15 00:00 |
13:46:28.61 |
-25:10:09.6 |
HIP 67071 |
30.60 |
| 2026-08-15 12:00 |
13:46:30.71 |
-25:10:12.8 |
HIP 67071 |
30.93 |
| 2026-08-16 00:00 |
13:46:32.85 |
-25:10:16.3 |
HIP 67071 |
31.26 |
| 2026-08-16 12:00 |
13:46:35.03 |
-25:10:20.0 |
HIP 67071 |
31.61 |
| 2026-08-17 00:00 |
13:46:37.24 |
-25:10:23.9 |
HIP 67071 |
31.96 |
| 2026-08-17 12:00 |
13:46:39.48 |
-25:10:28.1 |
HIP 67071 |
32.32 |
| 2026-08-18 00:00 |
13:46:41.76 |
-25:10:32.5 |
HIP 67071 |
32.68 |
| 2026-08-18 12:00 |
13:46:44.07 |
-25:10:37.1 |
HIP 67071 |
33.06 |
| 2026-08-19 00:00 |
13:46:46.41 |
-25:10:42.0 |
HIP 67071 |
33.44 |