| Parameter |
Value |
| Designation |
199P/Shoemaker 4 |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2009-04-08T02:25:25.942080Z |
| Orbit solution date (soln_date, UTC) |
2024-08-18T18:42:22Z |
| Obs used |
863 |
| NEO |
- |
| M1 |
7.400 |
| K1 |
16.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-04-27.0000000 |
| e |
0.50752456 |
| q (au) |
2.929047 |
| a (au) |
5.947599 |
| i (deg) |
24.756182 |
| Ω (om, deg) |
92.622289 |
| ω (w, deg) |
191.826638 |
| M (ma, deg) |
50.887927 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.239 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.239 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.902 |
| 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) |
| 2026-06-01 00:00 |
03:52:24.81 |
+06:16:55.5 |
HIP 18089 |
16.35 |
| 2026-06-01 12:00 |
03:52:44.65 |
+06:18:14.8 |
HIP 18089 |
17.71 |
| 2026-06-02 00:00 |
03:53:04.47 |
+06:19:33.5 |
HIP 18089 |
20.30 |
| 2026-06-02 12:00 |
03:53:24.27 |
+06:20:51.6 |
HIP 18089 |
23.71 |
| 2026-06-03 00:00 |
03:53:44.05 |
+06:22:09.0 |
HIP 18089 |
27.64 |
| 2026-06-03 12:00 |
03:54:03.80 |
+06:23:25.9 |
HIP 18224 |
28.49 |
| 2026-06-04 00:00 |
03:54:23.53 |
+06:24:42.2 |
HIP 18224 |
28.38 |
| 2026-06-04 12:00 |
03:54:43.24 |
+06:25:57.9 |
HIP 18224 |
29.16 |
| 2026-06-05 00:00 |
03:55:02.92 |
+06:27:13.0 |
HIP 18449 |
27.80 |
| 2026-06-05 12:00 |
03:55:22.58 |
+06:28:27.5 |
HIP 18449 |
23.11 |
| 2026-06-06 00:00 |
03:55:42.21 |
+06:29:41.5 |
HIP 18449 |
18.62 |
| 2026-06-06 12:00 |
03:56:01.81 |
+06:30:54.8 |
HIP 18449 |
14.49 |
| 2026-06-07 00:00 |
03:56:21.38 |
+06:32:07.5 |
HIP 18449 |
11.13 |
| 2026-06-07 12:00 |
03:56:40.93 |
+06:33:19.6 |
HIP 18449 |
9.39 |
| 2026-06-08 00:00 |
03:57:00.45 |
+06:34:31.1 |
HIP 18449 |
10.13 |
| 2026-06-08 12:00 |
03:57:19.94 |
+06:35:42.0 |
HIP 18449 |
12.92 |
| 2026-06-09 00:00 |
03:57:39.40 |
+06:36:52.3 |
HIP 18521 |
15.56 |
| 2026-06-09 12:00 |
03:57:58.83 |
+06:38:02.0 |
HIP 18521 |
15.29 |
| 2026-06-10 00:00 |
03:58:18.23 |
+06:39:11.1 |
HIP 18521 |
16.58 |
| 2026-06-10 12:00 |
03:58:37.60 |
+06:40:19.6 |
HIP 18521 |
19.10 |
| 2026-06-11 00:00 |
03:58:56.93 |
+06:41:27.4 |
HIP 18521 |
22.44 |
| 2026-06-11 12:00 |
03:59:16.24 |
+06:42:34.7 |
HIP 18521 |
26.29 |
| 2026-06-12 00:00 |
03:59:35.51 |
+06:43:41.4 |
HIP 18562 |
28.83 |
| 2026-06-12 12:00 |
03:59:54.74 |
+06:44:47.4 |
HIP 18562 |
31.22 |
| 2026-06-13 00:00 |
04:00:13.94 |
+06:45:52.8 |
HIP 18826 |
30.91 |
| 2026-06-13 12:00 |
04:00:33.10 |
+06:46:57.7 |
HIP 18826 |
27.39 |
| 2026-06-14 00:00 |
04:00:52.23 |
+06:48:01.9 |
HIP 18826 |
24.35 |
| 2026-06-14 12:00 |
04:01:11.31 |
+06:49:05.5 |
HIP 18826 |
21.97 |
| 2026-06-15 00:00 |
04:01:30.36 |
+06:50:08.5 |
HIP 18856 |
19.78 |
| 2026-06-15 12:00 |
04:01:49.38 |
+06:51:10.8 |
HIP 18856 |
17.14 |
| 2026-06-16 00:00 |
04:02:08.35 |
+06:52:12.6 |
HIP 18856 |
15.58 |
| 2026-06-16 12:00 |
04:02:27.28 |
+06:53:13.7 |
HIP 18856 |
15.42 |
| 2026-06-17 00:00 |
04:02:46.17 |
+06:54:14.3 |
HIP 18947 |
14.69 |
| 2026-06-17 12:00 |
04:03:05.01 |
+06:55:14.2 |
HIP 18947 |
11.38 |
| 2026-06-18 00:00 |
04:03:23.82 |
+06:56:13.5 |
HIP 18947 |
9.43 |
| 2026-06-18 12:00 |
04:03:42.58 |
+06:57:12.2 |
HIP 18947 |
9.67 |
| 2026-06-19 00:00 |
04:04:01.30 |
+06:58:10.2 |
HIP 18947 |
11.96 |
| 2026-06-19 12:00 |
04:04:19.97 |
+06:59:07.7 |
HIP 18947 |
15.40 |
| 2026-06-20 00:00 |
04:04:38.60 |
+07:00:04.5 |
HIP 18947 |
19.38 |
| 2026-06-20 12:00 |
04:04:57.18 |
+07:01:00.8 |
HIP 18947 |
23.62 |
| 2026-06-21 00:00 |
04:05:15.72 |
+07:01:56.4 |
HIP 18947 |
27.99 |
| 2026-06-21 12:00 |
04:05:34.21 |
+07:02:51.4 |
HIP 18947 |
32.44 |
| 2026-06-22 00:00 |
04:05:52.65 |
+07:03:45.8 |
HIP 18947 |
36.92 |