| Parameter |
Value |
| Designation |
C/2011 U3 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2012-06-03T21:30:23.644800Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:56Z |
| Obs used |
60 |
| NEO |
- |
| M1 |
11.800 |
| K1 |
14.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-11-08.0000000 |
| e |
1.00044923 |
| q (au) |
1.071437 |
| a (au) |
-2385.059256 |
| i (deg) |
116.775956 |
| Ω (om, deg) |
228.378920 |
| ω (w, deg) |
287.823893 |
| M (ma, deg) |
-0.001768 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.812 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.812 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.917 |
| k |
0.999 |
| 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) |
| 2026-09-20 00:00 |
13:04:38.40 |
+65:25:16.0 |
HIP 63893 |
16.23 |
| 2026-09-20 12:00 |
13:04:45.82 |
+65:24:55.2 |
HIP 63893 |
16.26 |
| 2026-09-21 00:00 |
13:04:53.27 |
+65:24:34.7 |
HIP 63893 |
16.33 |
| 2026-09-21 12:00 |
13:05:00.74 |
+65:24:14.6 |
HIP 63893 |
16.43 |
| 2026-09-22 00:00 |
13:05:08.22 |
+65:23:54.8 |
HIP 63893 |
16.58 |
| 2026-09-22 12:00 |
13:05:15.73 |
+65:23:35.5 |
HIP 63893 |
16.75 |
| 2026-09-23 00:00 |
13:05:23.25 |
+65:23:16.5 |
HIP 63893 |
16.96 |
| 2026-09-23 12:00 |
13:05:30.79 |
+65:22:57.9 |
HIP 63893 |
17.20 |
| 2026-09-24 00:00 |
13:05:38.35 |
+65:22:39.7 |
HIP 63893 |
17.47 |
| 2026-09-24 12:00 |
13:05:45.92 |
+65:22:21.8 |
HIP 63893 |
17.78 |
| 2026-09-25 00:00 |
13:05:53.52 |
+65:22:04.4 |
HIP 63893 |
18.10 |
| 2026-09-25 12:00 |
13:06:01.13 |
+65:21:47.3 |
HIP 63893 |
18.46 |
| 2026-09-26 00:00 |
13:06:08.75 |
+65:21:30.7 |
HIP 63893 |
18.84 |
| 2026-09-26 12:00 |
13:06:16.39 |
+65:21:14.4 |
HIP 63893 |
19.24 |
| 2026-09-27 00:00 |
13:06:24.05 |
+65:20:58.5 |
HIP 63893 |
19.66 |
| 2026-09-27 12:00 |
13:06:31.72 |
+65:20:43.0 |
HIP 64149 |
19.87 |
| 2026-09-28 00:00 |
13:06:39.41 |
+65:20:27.9 |
HIP 64149 |
19.48 |
| 2026-09-28 12:00 |
13:06:47.11 |
+65:20:13.2 |
HIP 64149 |
19.11 |
| 2026-09-29 00:00 |
13:06:54.82 |
+65:19:58.9 |
HIP 64149 |
18.76 |
| 2026-09-29 12:00 |
13:07:02.55 |
+65:19:45.0 |
HIP 64149 |
18.44 |
| 2026-09-30 00:00 |
13:07:10.29 |
+65:19:31.4 |
HIP 64149 |
18.15 |
| 2026-09-30 12:00 |
13:07:18.04 |
+65:19:18.3 |
HIP 64149 |
17.88 |
| 2026-10-01 00:00 |
13:07:25.80 |
+65:19:05.6 |
HIP 64149 |
17.64 |
| 2026-10-01 12:00 |
13:07:33.58 |
+65:18:53.3 |
HIP 64149 |
17.44 |
| 2026-10-02 00:00 |
13:07:41.36 |
+65:18:41.3 |
HIP 64149 |
17.26 |
| 2026-10-02 12:00 |
13:07:49.16 |
+65:18:29.8 |
HIP 64149 |
17.12 |
| 2026-10-03 00:00 |
13:07:56.96 |
+65:18:18.7 |
HIP 64149 |
17.01 |
| 2026-10-03 12:00 |
13:08:04.78 |
+65:18:08.0 |
HIP 64149 |
16.93 |
| 2026-10-04 00:00 |
13:08:12.61 |
+65:17:57.7 |
HIP 64149 |
16.88 |
| 2026-10-04 12:00 |
13:08:20.44 |
+65:17:47.8 |
HIP 64149 |
16.87 |
| 2026-10-05 00:00 |
13:08:28.28 |
+65:17:38.4 |
HIP 64149 |
16.90 |
| 2026-10-05 12:00 |
13:08:36.13 |
+65:17:29.3 |
HIP 64149 |
16.95 |
| 2026-10-06 00:00 |
13:08:43.99 |
+65:17:20.7 |
HIP 64149 |
17.04 |
| 2026-10-06 12:00 |
13:08:51.86 |
+65:17:12.5 |
HIP 64149 |
17.17 |
| 2026-10-07 00:00 |
13:08:59.73 |
+65:17:04.6 |
HIP 64149 |
17.32 |
| 2026-10-07 12:00 |
13:09:07.60 |
+65:16:57.2 |
HIP 64149 |
17.51 |
| 2026-10-08 00:00 |
13:09:15.49 |
+65:16:50.3 |
HIP 64149 |
17.73 |
| 2026-10-08 12:00 |
13:09:23.37 |
+65:16:43.7 |
HIP 64149 |
17.97 |
| 2026-10-09 00:00 |
13:09:31.27 |
+65:16:37.6 |
HIP 64149 |
18.24 |
| 2026-10-09 12:00 |
13:09:39.16 |
+65:16:31.9 |
HIP 64149 |
18.54 |
| 2026-10-10 00:00 |
13:09:47.06 |
+65:16:26.6 |
HIP 64294 |
18.39 |
| 2026-10-10 12:00 |
13:09:54.96 |
+65:16:21.7 |
HIP 64294 |
18.25 |
| 2026-10-11 00:00 |
13:10:02.87 |
+65:16:17.3 |
HIP 64294 |
18.14 |