| Parameter |
Value |
| Designation |
131P/Mueller 2 |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-01-06T10:51:40.682880Z |
| Orbit solution date (soln_date, UTC) |
2026-01-13T22:30:25Z |
| Obs used |
906 |
| NEO |
- |
| M1 |
8.500 |
| K1 |
24.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-07-12.0000000 |
| e |
0.34323033 |
| q (au) |
2.416401 |
| a (au) |
3.679222 |
| i (deg) |
7.354998 |
| Ω (om, deg) |
214.198600 |
| ω (w, deg) |
179.281630 |
| M (ma, deg) |
77.168435 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.656 + 2.200\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.656 |
| n |
2.200 |
| gf |
0.964 |
| gb |
-0.857 |
| k |
0.997 |
| 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) |
| 2026-05-12 00:00 |
03:39:09.55 |
+17:14:39.0 |
HIP 16983 |
23.73 |
| 2026-05-12 12:00 |
03:40:09.59 |
+17:17:17.6 |
HIP 16983 |
31.01 |
| 2026-05-13 00:00 |
03:41:09.65 |
+17:19:54.9 |
HIP 17336 |
20.97 |
| 2026-05-13 12:00 |
03:42:09.72 |
+17:22:31.0 |
HIP 17336 |
8.15 |
| 2026-05-14 00:00 |
03:43:09.79 |
+17:25:05.7 |
HIP 17336 |
10.84 |
| 2026-05-14 12:00 |
03:44:09.87 |
+17:27:39.1 |
HIP 17466 |
18.16 |
| 2026-05-15 00:00 |
03:45:09.96 |
+17:30:11.2 |
HIP 17466 |
16.94 |
| 2026-05-15 12:00 |
03:46:10.06 |
+17:32:41.9 |
HIP 17614 |
22.67 |
| 2026-05-16 00:00 |
03:47:10.17 |
+17:35:11.3 |
HIP 17614 |
22.54 |
| 2026-05-16 12:00 |
03:48:10.28 |
+17:37:39.4 |
HIP 17614 |
30.42 |
| 2026-05-17 00:00 |
03:49:10.40 |
+17:40:06.1 |
HIP 17960 |
20.75 |
| 2026-05-17 12:00 |
03:50:10.52 |
+17:42:31.5 |
HIP 17983 |
7.63 |
| 2026-05-18 00:00 |
03:51:10.64 |
+17:44:55.5 |
HIP 17983 |
8.04 |
| 2026-05-18 12:00 |
03:52:10.77 |
+17:47:18.2 |
HIP 18096 |
20.84 |
| 2026-05-19 00:00 |
03:53:10.90 |
+17:49:39.5 |
HIP 18096 |
24.20 |
| 2026-05-19 12:00 |
03:54:11.03 |
+17:51:59.4 |
HIP 18304 |
17.94 |
| 2026-05-20 00:00 |
03:55:11.16 |
+17:54:17.9 |
HIP 18354 |
16.72 |
| 2026-05-20 12:00 |
03:56:11.29 |
+17:56:35.1 |
HIP 18354 |
21.51 |
| 2026-05-21 00:00 |
03:57:11.42 |
+17:58:50.9 |
HIP 18354 |
32.64 |
| 2026-05-21 12:00 |
03:58:11.55 |
+18:01:05.3 |
HIP 18735 |
38.80 |
| 2026-05-22 00:00 |
03:59:11.67 |
+18:03:18.3 |
HIP 18735 |
24.51 |
| 2026-05-22 12:00 |
04:00:11.80 |
+18:05:29.9 |
HIP 18735 |
10.70 |
| 2026-05-23 00:00 |
04:01:11.92 |
+18:07:40.1 |
HIP 18735 |
6.80 |
| 2026-05-23 12:00 |
04:02:12.03 |
+18:09:48.9 |
HIP 18849 |
7.28 |
| 2026-05-24 00:00 |
04:03:12.14 |
+18:11:56.3 |
HIP 18849 |
13.23 |
| 2026-05-24 12:00 |
04:04:12.24 |
+18:14:02.3 |
HIP 18849 |
26.71 |
| 2026-05-25 00:00 |
04:05:12.34 |
+18:16:06.9 |
HIP 19098 |
20.88 |
| 2026-05-25 12:00 |
04:06:12.44 |
+18:18:10.1 |
HIP 19098 |
23.25 |
| 2026-05-26 00:00 |
04:07:12.52 |
+18:20:11.9 |
HIP 19098 |
32.56 |
| 2026-05-26 12:00 |
04:08:12.60 |
+18:22:12.2 |
HIP 19470 |
28.95 |
| 2026-05-27 00:00 |
04:09:12.67 |
+18:24:11.2 |
HIP 19470 |
14.66 |
| 2026-05-27 12:00 |
04:10:12.73 |
+18:26:08.7 |
HIP 19470 |
2.34 |
| 2026-05-28 00:00 |
04:11:12.78 |
+18:28:04.8 |
HIP 19549 |
5.27 |
| 2026-05-28 12:00 |
04:12:12.82 |
+18:29:59.4 |
HIP 19549 |
15.88 |
| 2026-05-29 00:00 |
04:13:12.86 |
+18:31:52.7 |
HIP 19763 |
26.27 |
| 2026-05-29 12:00 |
04:14:12.88 |
+18:33:44.5 |
HIP 19847 |
15.75 |
| 2026-05-30 00:00 |
04:15:12.89 |
+18:35:34.8 |
HIP 19847 |
2.22 |
| 2026-05-30 12:00 |
04:16:12.89 |
+18:37:23.7 |
HIP 19847 |
13.14 |
| 2026-05-31 00:00 |
04:17:12.88 |
+18:39:11.2 |
HIP 19988 |
17.77 |
| 2026-05-31 12:00 |
04:18:12.85 |
+18:40:57.3 |
HIP 19988 |
21.14 |
| 2026-06-01 00:00 |
04:19:12.82 |
+18:42:41.9 |
HIP 20255 |
17.20 |
| 2026-06-01 12:00 |
04:20:12.76 |
+18:44:25.0 |
HIP 20255 |
2.91 |
| 2026-06-02 00:00 |
04:21:12.70 |
+18:46:06.8 |
HIP 20255 |
11.39 |