| 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) |
| 2026-05-12 00:00 |
13:01:51.64 |
+68:21:51.0 |
HIP 63602 |
8.01 |
| 2026-05-12 12:00 |
13:01:43.69 |
+68:21:27.6 |
HIP 63602 |
7.77 |
| 2026-05-13 00:00 |
13:01:35.79 |
+68:21:03.9 |
HIP 63602 |
7.61 |
| 2026-05-13 12:00 |
13:01:27.95 |
+68:20:39.7 |
HIP 63602 |
7.53 |
| 2026-05-14 00:00 |
13:01:20.16 |
+68:20:15.1 |
HIP 63602 |
7.53 |
| 2026-05-14 12:00 |
13:01:12.42 |
+68:19:50.1 |
HIP 63602 |
7.61 |
| 2026-05-15 00:00 |
13:01:04.74 |
+68:19:24.6 |
HIP 63602 |
7.77 |
| 2026-05-15 12:00 |
13:00:57.12 |
+68:18:58.8 |
HIP 63602 |
8.01 |
| 2026-05-16 00:00 |
13:00:49.55 |
+68:18:32.6 |
HIP 63602 |
8.31 |
| 2026-05-16 12:00 |
13:00:42.04 |
+68:18:05.9 |
HIP 63602 |
8.67 |
| 2026-05-17 00:00 |
13:00:34.59 |
+68:17:38.9 |
HIP 63602 |
9.09 |
| 2026-05-17 12:00 |
13:00:27.19 |
+68:17:11.5 |
HIP 63602 |
9.56 |
| 2026-05-18 00:00 |
13:00:19.85 |
+68:16:43.6 |
HIP 63602 |
10.06 |
| 2026-05-18 12:00 |
13:00:12.58 |
+68:16:15.4 |
HIP 63602 |
10.60 |
| 2026-05-19 00:00 |
13:00:05.36 |
+68:15:46.8 |
HIP 63602 |
11.16 |
| 2026-05-19 12:00 |
12:59:58.20 |
+68:15:17.8 |
HIP 63602 |
11.75 |
| 2026-05-20 00:00 |
12:59:51.10 |
+68:14:48.4 |
HIP 63602 |
12.36 |
| 2026-05-20 12:00 |
12:59:44.07 |
+68:14:18.7 |
HIP 63602 |
12.99 |
| 2026-05-21 00:00 |
12:59:37.09 |
+68:13:48.6 |
HIP 63602 |
13.64 |
| 2026-05-21 12:00 |
12:59:30.18 |
+68:13:18.1 |
HIP 63602 |
14.29 |
| 2026-05-22 00:00 |
12:59:23.33 |
+68:12:47.2 |
HIP 63602 |
14.96 |
| 2026-05-22 12:00 |
12:59:16.54 |
+68:12:16.0 |
HIP 63602 |
15.64 |
| 2026-05-23 00:00 |
12:59:09.82 |
+68:11:44.4 |
HIP 63602 |
16.32 |
| 2026-05-23 12:00 |
12:59:03.16 |
+68:11:12.5 |
HIP 63602 |
17.02 |
| 2026-05-24 00:00 |
12:58:56.56 |
+68:10:40.2 |
HIP 63602 |
17.71 |
| 2026-05-24 12:00 |
12:58:50.03 |
+68:10:07.6 |
HIP 63602 |
18.42 |
| 2026-05-25 00:00 |
12:58:43.56 |
+68:09:34.6 |
HIP 63602 |
19.13 |
| 2026-05-25 12:00 |
12:58:37.16 |
+68:09:01.3 |
HIP 63602 |
19.84 |
| 2026-05-26 00:00 |
12:58:30.82 |
+68:08:27.6 |
HIP 63602 |
20.56 |
| 2026-05-26 12:00 |
12:58:24.55 |
+68:07:53.6 |
HIP 63602 |
21.28 |
| 2026-05-27 00:00 |
12:58:18.35 |
+68:07:19.3 |
HIP 63602 |
22.00 |
| 2026-05-27 12:00 |
12:58:12.21 |
+68:06:44.6 |
HIP 63602 |
22.72 |
| 2026-05-28 00:00 |
12:58:06.14 |
+68:06:09.6 |
HIP 63602 |
23.45 |
| 2026-05-28 12:00 |
12:58:00.14 |
+68:05:34.3 |
HIP 63602 |
24.18 |
| 2026-05-29 00:00 |
12:57:54.20 |
+68:04:58.7 |
HIP 63602 |
24.91 |
| 2026-05-29 12:00 |
12:57:48.33 |
+68:04:22.7 |
HIP 63114 |
24.16 |
| 2026-05-30 00:00 |
12:57:42.53 |
+68:03:46.5 |
HIP 63114 |
23.38 |
| 2026-05-30 12:00 |
12:57:36.80 |
+68:03:09.9 |
HIP 63114 |
22.60 |
| 2026-05-31 00:00 |
12:57:31.14 |
+68:02:33.0 |
HIP 63114 |
21.82 |
| 2026-05-31 12:00 |
12:57:25.54 |
+68:01:55.8 |
HIP 63114 |
21.04 |
| 2026-06-01 00:00 |
12:57:20.02 |
+68:01:18.3 |
HIP 63114 |
20.26 |
| 2026-06-01 12:00 |
12:57:14.56 |
+68:00:40.6 |
HIP 63114 |
19.49 |
| 2026-06-02 00:00 |
12:57:09.17 |
+68:00:02.5 |
HIP 63114 |
18.71 |