| 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 |
0.955 |
| 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) |
| 2026-06-01 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 |
| 2026-06-02 12:00 |
04:22:12.62 |
+18:47:47.0 |
HIP 20350 |
24.66 |
| 2026-06-03 00:00 |
04:23:12.53 |
+18:49:25.8 |
HIP 20600 |
22.05 |
| 2026-06-03 12:00 |
04:24:12.42 |
+18:51:03.2 |
HIP 20600 |
8.13 |
| 2026-06-04 00:00 |
04:25:12.29 |
+18:52:39.1 |
HIP 20646 |
3.71 |
| 2026-06-04 12:00 |
04:26:12.15 |
+18:54:13.5 |
HIP 20686 |
5.40 |
| 2026-06-05 00:00 |
04:27:11.99 |
+18:55:46.5 |
HIP 20769 |
11.62 |
| 2026-06-05 12:00 |
04:28:11.81 |
+18:57:18.1 |
HIP 20889 |
14.77 |
| 2026-06-06 00:00 |
04:29:11.62 |
+18:58:48.1 |
HIP 20889 |
14.55 |
| 2026-06-06 12:00 |
04:30:11.40 |
+19:00:16.7 |
HIP 21089 |
17.81 |
| 2026-06-07 00:00 |
04:31:11.17 |
+19:01:43.9 |
HIP 21089 |
12.52 |
| 2026-06-07 12:00 |
04:32:10.92 |
+19:03:09.5 |
HIP 21089 |
19.97 |
| 2026-06-08 00:00 |
04:33:10.64 |
+19:04:33.7 |
HIP 21261 |
8.26 |
| 2026-06-08 12:00 |
04:34:10.35 |
+19:05:56.4 |
HIP 21261 |
8.44 |
| 2026-06-09 00:00 |
04:35:10.03 |
+19:07:17.7 |
HIP 21261 |
21.81 |
| 2026-06-09 12:00 |
04:36:09.69 |
+19:08:37.5 |
HIP 21467 |
24.25 |
| 2026-06-10 00:00 |
04:37:09.33 |
+19:09:55.8 |
HIP 21467 |
25.74 |
| 2026-06-10 12:00 |
04:38:08.94 |
+19:11:12.6 |
HIP 21687 |
17.89 |
| 2026-06-11 00:00 |
04:39:08.53 |
+19:12:27.9 |
HIP 21687 |
6.31 |
| 2026-06-11 12:00 |
04:40:08.09 |
+19:13:41.8 |
HIP 21687 |
12.58 |
| 2026-06-12 00:00 |
04:41:07.63 |
+19:14:54.1 |
HIP 21831 |
21.68 |
| 2026-06-12 12:00 |
04:42:07.14 |
+19:16:05.0 |
HIP 21831 |
20.84 |
| 2026-06-13 00:00 |
04:43:06.62 |
+19:17:14.4 |
HIP 21932 |
19.77 |
| 2026-06-13 12:00 |
04:44:06.07 |
+19:18:22.3 |
HIP 22105 |
19.44 |
| 2026-06-14 00:00 |
04:45:05.50 |
+19:19:28.7 |
HIP 22105 |
5.45 |
| 2026-06-14 12:00 |
04:46:04.89 |
+19:20:33.6 |
HIP 22112 |
7.18 |
| 2026-06-15 00:00 |
04:47:04.25 |
+19:21:37.1 |
HIP 22211 |
10.45 |
| 2026-06-15 12:00 |
04:48:03.58 |
+19:22:39.0 |
HIP 22211 |
21.83 |
| 2026-06-16 00:00 |
04:49:02.87 |
+19:23:39.5 |
HIP 22357 |
20.18 |
| 2026-06-16 12:00 |
04:50:02.13 |
+19:24:38.4 |
HIP 22357 |
26.00 |
| 2026-06-17 00:00 |
04:51:01.35 |
+19:25:35.9 |
HIP 22623 |
18.82 |
| 2026-06-17 12:00 |
04:52:00.54 |
+19:26:31.8 |
HIP 22623 |
12.74 |
| 2026-06-18 00:00 |
04:52:59.69 |
+19:27:26.3 |
HIP 22623 |
19.01 |
| 2026-06-18 12:00 |
04:53:58.81 |
+19:28:19.3 |
HIP 22850 |
14.05 |
| 2026-06-19 00:00 |
04:54:57.88 |
+19:29:10.8 |
HIP 22850 |
0.12 |
| 2026-06-19 12:00 |
04:55:56.91 |
+19:30:00.8 |
HIP 22850 |
13.84 |
| 2026-06-20 00:00 |
04:56:55.91 |
+19:30:49.3 |
HIP 22850 |
27.76 |
| 2026-06-20 12:00 |
04:57:54.86 |
+19:31:36.3 |
HIP 23178 |
21.93 |
| 2026-06-21 00:00 |
04:58:53.77 |
+19:32:21.8 |
HIP 23178 |
12.93 |
| 2026-06-21 12:00 |
04:59:52.64 |
+19:33:05.8 |
HIP 23178 |
15.49 |
| 2026-06-22 00:00 |
05:00:51.47 |
+19:33:48.4 |
HIP 23356 |
23.14 |