| Parameter |
Value |
| Designation |
149P/Mueller 4 |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2010-02-18T16:52:27.373440Z |
| Orbit solution date (soln_date, UTC) |
2023-05-03T22:44:05Z |
| Obs used |
494 |
| NEO |
- |
| M1 |
15.500 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-05-05.0000000 |
| e |
0.38831799 |
| q (au) |
2.646439 |
| a (au) |
4.326494 |
| i (deg) |
29.754798 |
| Ω (om, deg) |
145.255090 |
| ω (w, deg) |
43.567077 |
| M (ma, deg) |
128.282351 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.267 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.267 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.532 |
| k |
0.800 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
06:34:16.62 |
+05:19:55.8 |
HIP 31246 |
17.78 |
| 2026-03-26 12:00 |
06:34:33.46 |
+05:25:10.0 |
HIP 31466 |
14.86 |
| 2026-03-27 00:00 |
06:34:50.57 |
+05:30:22.9 |
HIP 31466 |
9.52 |
| 2026-03-27 12:00 |
06:35:07.95 |
+05:35:34.3 |
HIP 31466 |
7.08 |
| 2026-03-28 00:00 |
06:35:25.61 |
+05:40:44.3 |
HIP 31466 |
10.02 |
| 2026-03-28 12:00 |
06:35:43.53 |
+05:45:52.8 |
HIP 31466 |
15.56 |
| 2026-03-29 00:00 |
06:36:01.72 |
+05:51:00.0 |
HIP 31567 |
15.23 |
| 2026-03-29 12:00 |
06:36:20.18 |
+05:56:05.6 |
HIP 31567 |
9.01 |
| 2026-03-30 00:00 |
06:36:38.90 |
+06:01:09.7 |
HIP 31567 |
5.01 |
| 2026-03-30 12:00 |
06:36:57.88 |
+06:06:12.5 |
HIP 31646 |
6.78 |
| 2026-03-31 00:00 |
06:37:17.12 |
+06:11:13.7 |
HIP 31646 |
3.55 |
| 2026-03-31 12:00 |
06:37:36.62 |
+06:16:13.5 |
HIP 31646 |
8.68 |
| 2026-04-01 00:00 |
06:37:56.38 |
+06:21:11.7 |
HIP 31646 |
15.35 |
| 2026-04-01 12:00 |
06:38:16.39 |
+06:26:08.5 |
HIP 31694 |
16.09 |
| 2026-04-02 00:00 |
06:38:36.66 |
+06:31:03.8 |
HIP 31694 |
14.98 |
| 2026-04-02 12:00 |
06:38:57.19 |
+06:35:57.6 |
HIP 31694 |
17.07 |
| 2026-04-03 00:00 |
06:39:17.96 |
+06:40:49.8 |
HIP 31787 |
15.23 |
| 2026-04-03 12:00 |
06:39:38.98 |
+06:45:40.6 |
HIP 31787 |
15.23 |
| 2026-04-04 00:00 |
06:40:00.26 |
+06:50:29.8 |
HIP 31787 |
18.31 |
| 2026-04-04 12:00 |
06:40:21.78 |
+06:55:17.5 |
HIP 31787 |
23.32 |
| 2026-04-05 00:00 |
06:40:43.54 |
+07:00:03.6 |
HIP 31838 |
25.51 |
| 2026-04-05 12:00 |
06:41:05.55 |
+07:04:48.3 |
HIP 32094 |
26.05 |
| 2026-04-06 00:00 |
06:41:27.81 |
+07:09:31.3 |
HIP 32094 |
18.85 |
| 2026-04-06 12:00 |
06:41:50.30 |
+07:14:12.9 |
HIP 32094 |
11.73 |
| 2026-04-07 00:00 |
06:42:13.04 |
+07:18:52.9 |
HIP 32094 |
5.09 |
| 2026-04-07 12:00 |
06:42:36.02 |
+07:23:31.3 |
HIP 32094 |
4.69 |
| 2026-04-08 00:00 |
06:42:59.23 |
+07:28:08.2 |
HIP 32094 |
11.27 |
| 2026-04-08 12:00 |
06:43:22.68 |
+07:32:43.5 |
HIP 32094 |
18.50 |
| 2026-04-09 00:00 |
06:43:46.36 |
+07:37:17.2 |
HIP 32094 |
25.87 |
| 2026-04-09 12:00 |
06:44:10.28 |
+07:41:49.4 |
HIP 32094 |
33.30 |
| 2026-04-10 00:00 |
06:44:34.43 |
+07:46:19.9 |
HIP 32445 |
36.87 |
| 2026-04-10 12:00 |
06:44:58.82 |
+07:50:48.9 |
HIP 32260 |
36.25 |
| 2026-04-11 00:00 |
06:45:23.43 |
+07:55:16.3 |
HIP 32533 |
29.65 |
| 2026-04-11 12:00 |
06:45:48.27 |
+07:59:42.2 |
HIP 32533 |
22.81 |
| 2026-04-12 00:00 |
06:46:13.33 |
+08:04:06.4 |
HIP 32533 |
16.57 |
| 2026-04-12 12:00 |
06:46:38.63 |
+08:08:29.0 |
HIP 32533 |
11.96 |
| 2026-04-13 00:00 |
06:47:04.14 |
+08:12:50.0 |
HIP 32475 |
10.67 |
| 2026-04-13 12:00 |
06:47:29.89 |
+08:17:09.5 |
HIP 32475 |
13.01 |
| 2026-04-14 00:00 |
06:47:55.85 |
+08:21:27.3 |
HIP 32526 |
14.01 |
| 2026-04-14 12:00 |
06:48:22.03 |
+08:25:43.4 |
HIP 32686 |
12.34 |
| 2026-04-15 00:00 |
06:48:48.43 |
+08:29:58.0 |
HIP 32686 |
10.23 |
| 2026-04-15 12:00 |
06:49:15.05 |
+08:34:11.0 |
HIP 32686 |
13.34 |
| 2026-04-16 00:00 |
06:49:41.89 |
+08:38:22.3 |
HIP 32686 |
19.32 |