C/2011 U3 (PANSTARRS)
| 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) |
| 2026-02-03 00:00 |
13:28:13.52 |
+67:09:07.0 |
HIP 65773 |
8.15 |
| 2026-02-03 12:00 |
13:28:10.11 |
+67:10:04.8 |
HIP 65773 |
9.13 |
| 2026-02-04 00:00 |
13:28:06.61 |
+67:11:02.5 |
HIP 65773 |
10.12 |
| 2026-02-04 12:00 |
13:28:03.03 |
+67:12:00.0 |
HIP 65773 |
11.11 |
| 2026-02-05 00:00 |
13:27:59.37 |
+67:12:57.3 |
HIP 65773 |
12.11 |
| 2026-02-05 12:00 |
13:27:55.63 |
+67:13:54.6 |
HIP 65773 |
13.12 |
| 2026-02-06 00:00 |
13:27:51.81 |
+67:14:51.6 |
HIP 65773 |
14.13 |
| 2026-02-06 12:00 |
13:27:47.91 |
+67:15:48.5 |
HIP 65773 |
15.14 |
| 2026-02-07 00:00 |
13:27:43.93 |
+67:16:45.2 |
HIP 65773 |
16.15 |
| 2026-02-07 12:00 |
13:27:39.88 |
+67:17:41.8 |
HIP 65773 |
17.17 |
| 2026-02-08 00:00 |
13:27:35.74 |
+67:18:38.1 |
HIP 65773 |
18.19 |
| 2026-02-08 12:00 |
13:27:31.52 |
+67:19:34.3 |
HIP 65773 |
19.20 |
| 2026-02-09 00:00 |
13:27:27.22 |
+67:20:30.3 |
HIP 65773 |
20.22 |
| 2026-02-09 12:00 |
13:27:22.85 |
+67:21:26.2 |
HIP 65773 |
21.24 |
| 2026-02-10 00:00 |
13:27:18.39 |
+67:22:21.8 |
HIP 65773 |
22.26 |
| 2026-02-10 12:00 |
13:27:13.86 |
+67:23:17.2 |
HIP 65773 |
23.28 |
| 2026-02-11 00:00 |
13:27:09.25 |
+67:24:12.4 |
HIP 65773 |
24.30 |
| 2026-02-11 12:00 |
13:27:04.56 |
+67:25:07.4 |
HIP 65773 |
25.33 |
| 2026-02-12 00:00 |
13:26:59.79 |
+67:26:02.2 |
HIP 65773 |
26.35 |
| 2026-02-12 12:00 |
13:26:54.94 |
+67:26:56.7 |
HIP 65773 |
27.37 |
| 2026-02-13 00:00 |
13:26:50.02 |
+67:27:51.1 |
HIP 65773 |
28.39 |
| 2026-02-13 12:00 |
13:26:45.02 |
+67:28:45.2 |
HIP 65773 |
29.41 |
| 2026-02-14 00:00 |
13:26:39.94 |
+67:29:39.1 |
HIP 65773 |
30.43 |
| 2026-02-14 12:00 |
13:26:34.79 |
+67:30:32.7 |
HIP 65773 |
31.45 |
| 2026-02-15 00:00 |
13:26:29.56 |
+67:31:26.1 |
HIP 65773 |
32.47 |
| 2026-02-15 12:00 |
13:26:24.25 |
+67:32:19.3 |
HIP 65773 |
33.49 |
| 2026-02-16 00:00 |
13:26:18.87 |
+67:33:12.2 |
HIP 65773 |
34.51 |
| 2026-02-16 12:00 |
13:26:13.42 |
+67:34:04.8 |
HIP 65773 |
35.53 |
| 2026-02-17 00:00 |
13:26:07.88 |
+67:34:57.2 |
HIP 65449 |
36.34 |
| 2026-02-17 12:00 |
13:26:02.28 |
+67:35:49.3 |
HIP 65449 |
35.38 |
| 2026-02-18 00:00 |
13:25:56.60 |
+67:36:41.1 |
HIP 65449 |
34.43 |
| 2026-02-18 12:00 |
13:25:50.85 |
+67:37:32.7 |
HIP 65449 |
33.49 |
| 2026-02-19 00:00 |
13:25:45.02 |
+67:38:24.0 |
HIP 65449 |
32.56 |
| 2026-02-19 12:00 |
13:25:39.12 |
+67:39:15.0 |
HIP 65449 |
31.63 |
| 2026-02-20 00:00 |
13:25:33.15 |
+67:40:05.7 |
HIP 65449 |
30.71 |
| 2026-02-20 12:00 |
13:25:27.11 |
+67:40:56.1 |
HIP 65449 |
29.81 |
| 2026-02-21 00:00 |
13:25:20.99 |
+67:41:46.2 |
HIP 65449 |
28.91 |
| 2026-02-21 12:00 |
13:25:14.81 |
+67:42:36.0 |
HIP 65449 |
28.03 |
| 2026-02-22 00:00 |
13:25:08.55 |
+67:43:25.5 |
HIP 65449 |
27.17 |
| 2026-02-22 12:00 |
13:25:02.23 |
+67:44:14.7 |
HIP 65449 |
26.31 |
| 2026-02-23 00:00 |
13:24:55.83 |
+67:45:03.6 |
HIP 65449 |
25.48 |
| 2026-02-23 12:00 |
13:24:49.37 |
+67:45:52.2 |
HIP 65449 |
24.66 |
| 2026-02-24 00:00 |
13:24:42.84 |
+67:46:40.4 |
HIP 65449 |
23.86 |