| Parameter |
Value |
| Designation |
155P/Shoemaker 3 |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2002-12-08T02:13:30.930240Z |
| Orbit solution date (soln_date, UTC) |
2022-12-31T16:13:39Z |
| Obs used |
1966 |
| NEO |
- |
| M1 |
10.000 |
| K1 |
12.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-05-21.0000000 |
| e |
0.72610716 |
| q (au) |
1.806142 |
| a (au) |
6.594337 |
| i (deg) |
6.398094 |
| Ω (om, deg) |
97.276219 |
| ω (w, deg) |
14.601886 |
| M (ma, deg) |
179.609901 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.890 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.890 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
1.000 |
| 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) |
| 2026-07-29 00:00 |
18:47:16.74 |
-23:42:55.9 |
HIP 92240 |
28.90 |
| 2026-07-29 12:00 |
18:47:07.45 |
-23:43:08.5 |
HIP 91993 |
29.48 |
| 2026-07-30 00:00 |
18:46:58.22 |
-23:43:21.0 |
HIP 91993 |
27.44 |
| 2026-07-30 12:00 |
18:46:49.03 |
-23:43:33.3 |
HIP 91993 |
25.41 |
| 2026-07-31 00:00 |
18:46:39.91 |
-23:43:45.6 |
HIP 91993 |
23.42 |
| 2026-07-31 12:00 |
18:46:30.84 |
-23:43:57.7 |
HIP 91993 |
21.46 |
| 2026-08-01 00:00 |
18:46:21.82 |
-23:44:09.8 |
HIP 91993 |
19.53 |
| 2026-08-01 12:00 |
18:46:12.86 |
-23:44:21.7 |
HIP 91993 |
17.66 |
| 2026-08-02 00:00 |
18:46:03.96 |
-23:44:33.5 |
HIP 91993 |
15.83 |
| 2026-08-02 12:00 |
18:45:55.11 |
-23:44:45.2 |
HIP 91993 |
14.08 |
| 2026-08-03 00:00 |
18:45:46.33 |
-23:44:56.7 |
HIP 91993 |
12.43 |
| 2026-08-03 12:00 |
18:45:37.60 |
-23:45:08.2 |
HIP 91993 |
10.92 |
| 2026-08-04 00:00 |
18:45:28.94 |
-23:45:19.6 |
HIP 91993 |
9.59 |
| 2026-08-04 12:00 |
18:45:20.34 |
-23:45:30.8 |
HIP 91993 |
8.53 |
| 2026-08-05 00:00 |
18:45:11.80 |
-23:45:41.9 |
HIP 91993 |
7.85 |
| 2026-08-05 12:00 |
18:45:03.32 |
-23:45:52.9 |
HIP 91993 |
7.61 |
| 2026-08-06 00:00 |
18:44:54.91 |
-23:46:03.8 |
HIP 91993 |
7.87 |
| 2026-08-06 12:00 |
18:44:46.56 |
-23:46:14.6 |
HIP 91993 |
8.56 |
| 2026-08-07 00:00 |
18:44:38.28 |
-23:46:25.2 |
HIP 91993 |
9.58 |
| 2026-08-07 12:00 |
18:44:30.06 |
-23:46:35.8 |
HIP 91993 |
10.83 |
| 2026-08-08 00:00 |
18:44:21.92 |
-23:46:46.2 |
HIP 91993 |
12.23 |
| 2026-08-08 12:00 |
18:44:13.84 |
-23:46:56.5 |
HIP 91993 |
13.73 |
| 2026-08-09 00:00 |
18:44:05.83 |
-23:47:06.7 |
HIP 91993 |
15.29 |
| 2026-08-09 12:00 |
18:43:57.89 |
-23:47:16.8 |
HIP 91993 |
16.90 |
| 2026-08-10 00:00 |
18:43:50.02 |
-23:47:26.8 |
HIP 91993 |
18.53 |
| 2026-08-10 12:00 |
18:43:42.22 |
-23:47:36.6 |
HIP 91993 |
20.18 |
| 2026-08-11 00:00 |
18:43:34.50 |
-23:47:46.3 |
HIP 91993 |
21.83 |
| 2026-08-11 12:00 |
18:43:26.85 |
-23:47:55.9 |
HIP 91689 |
21.88 |
| 2026-08-12 00:00 |
18:43:19.27 |
-23:48:05.4 |
HIP 91689 |
20.14 |
| 2026-08-12 12:00 |
18:43:11.77 |
-23:48:14.8 |
HIP 91689 |
18.42 |
| 2026-08-13 00:00 |
18:43:04.35 |
-23:48:24.1 |
HIP 91689 |
16.71 |
| 2026-08-13 12:00 |
18:42:57.00 |
-23:48:33.2 |
HIP 91689 |
15.02 |
| 2026-08-14 00:00 |
18:42:49.73 |
-23:48:42.3 |
HIP 91689 |
13.35 |
| 2026-08-14 12:00 |
18:42:42.53 |
-23:48:51.2 |
HIP 91689 |
11.70 |
| 2026-08-15 00:00 |
18:42:35.42 |
-23:49:00.0 |
HIP 91689 |
10.07 |
| 2026-08-15 12:00 |
18:42:28.38 |
-23:49:08.7 |
HIP 91689 |
8.45 |
| 2026-08-16 00:00 |
18:42:21.43 |
-23:49:17.2 |
HIP 91689 |
6.86 |
| 2026-08-16 12:00 |
18:42:14.55 |
-23:49:25.7 |
HIP 91689 |
5.28 |
| 2026-08-17 00:00 |
18:42:07.76 |
-23:49:34.0 |
HIP 91689 |
3.72 |
| 2026-08-17 12:00 |
18:42:01.05 |
-23:49:42.2 |
HIP 91689 |
2.18 |
| 2026-08-18 00:00 |
18:41:54.42 |
-23:49:50.3 |
HIP 91689 |
0.66 |
| 2026-08-18 12:00 |
18:41:47.87 |
-23:49:58.3 |
HIP 91689 |
0.85 |
| 2026-08-19 00:00 |
18:41:41.41 |
-23:50:06.2 |
HIP 91689 |
2.33 |