199P/Shoemaker 4
| 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) |
| 2026-02-03 00:00 |
02:48:31.23 |
-02:23:19.1 |
HIP 13323 |
44.34 |
| 2026-02-03 12:00 |
02:48:37.26 |
-02:20:45.9 |
HIP 13323 |
42.91 |
| 2026-02-04 00:00 |
02:48:43.43 |
-02:18:12.5 |
HIP 13323 |
41.61 |
| 2026-02-04 12:00 |
02:48:49.75 |
-02:15:38.8 |
HIP 13323 |
40.46 |
| 2026-02-05 00:00 |
02:48:56.22 |
-02:13:04.9 |
HIP 13323 |
39.46 |
| 2026-02-05 12:00 |
02:49:02.83 |
-02:10:30.8 |
HIP 13323 |
38.65 |
| 2026-02-06 00:00 |
02:49:09.58 |
-02:07:56.5 |
HIP 13128 |
37.60 |
| 2026-02-06 12:00 |
02:49:16.47 |
-02:05:21.9 |
HIP 13128 |
35.30 |
| 2026-02-07 00:00 |
02:49:23.51 |
-02:02:47.2 |
HIP 13128 |
33.14 |
| 2026-02-07 12:00 |
02:49:30.69 |
-02:00:12.2 |
HIP 13128 |
31.15 |
| 2026-02-08 00:00 |
02:49:38.01 |
-01:57:37.1 |
HIP 13128 |
29.37 |
| 2026-02-08 12:00 |
02:49:45.47 |
-01:55:01.8 |
HIP 13128 |
27.86 |
| 2026-02-09 00:00 |
02:49:53.07 |
-01:52:26.3 |
HIP 13128 |
26.66 |
| 2026-02-09 12:00 |
02:50:00.81 |
-01:49:50.7 |
HIP 13128 |
25.83 |
| 2026-02-10 00:00 |
02:50:08.68 |
-01:47:14.8 |
HIP 13128 |
25.41 |
| 2026-02-10 12:00 |
02:50:16.69 |
-01:44:38.9 |
HIP 13128 |
25.43 |
| 2026-02-11 00:00 |
02:50:24.84 |
-01:42:02.8 |
HIP 13369 |
24.19 |
| 2026-02-11 12:00 |
02:50:33.13 |
-01:39:26.5 |
HIP 13369 |
22.93 |
| 2026-02-12 00:00 |
02:50:41.55 |
-01:36:50.2 |
HIP 13369 |
22.08 |
| 2026-02-12 12:00 |
02:50:50.10 |
-01:34:13.7 |
HIP 13369 |
21.70 |
| 2026-02-13 00:00 |
02:50:58.79 |
-01:31:37.0 |
HIP 13369 |
21.81 |
| 2026-02-13 12:00 |
02:51:07.61 |
-01:29:00.3 |
HIP 13320 |
19.66 |
| 2026-02-14 00:00 |
02:51:16.57 |
-01:26:23.5 |
HIP 13320 |
16.67 |
| 2026-02-14 12:00 |
02:51:25.65 |
-01:23:46.6 |
HIP 13320 |
13.89 |
| 2026-02-15 00:00 |
02:51:34.87 |
-01:21:09.6 |
HIP 13320 |
11.49 |
| 2026-02-15 12:00 |
02:51:44.22 |
-01:18:32.5 |
HIP 13320 |
9.78 |
| 2026-02-16 00:00 |
02:51:53.69 |
-01:15:55.3 |
HIP 13320 |
9.18 |
| 2026-02-16 12:00 |
02:52:03.30 |
-01:13:18.1 |
HIP 13320 |
9.93 |
| 2026-02-17 00:00 |
02:52:13.03 |
-01:10:40.8 |
HIP 13320 |
11.78 |
| 2026-02-17 12:00 |
02:52:22.89 |
-01:08:03.5 |
HIP 13320 |
14.34 |
| 2026-02-18 00:00 |
02:52:32.87 |
-01:05:26.1 |
HIP 13320 |
17.30 |
| 2026-02-18 12:00 |
02:52:42.98 |
-01:02:48.7 |
HIP 13320 |
20.50 |
| 2026-02-19 00:00 |
02:52:53.22 |
-01:00:11.3 |
HIP 13379 |
23.58 |
| 2026-02-19 12:00 |
02:53:03.58 |
-00:57:33.8 |
HIP 13379 |
22.64 |
| 2026-02-20 00:00 |
02:53:14.06 |
-00:54:56.3 |
HIP 13379 |
22.29 |
| 2026-02-20 12:00 |
02:53:24.66 |
-00:52:18.8 |
HIP 13379 |
22.58 |
| 2026-02-21 00:00 |
02:53:35.39 |
-00:49:41.3 |
HIP 13379 |
23.49 |
| 2026-02-21 12:00 |
02:53:46.23 |
-00:47:03.9 |
HIP 13379 |
24.97 |
| 2026-02-22 00:00 |
02:53:57.20 |
-00:44:26.4 |
HIP 13379 |
26.93 |
| 2026-02-22 12:00 |
02:54:08.28 |
-00:41:49.0 |
HIP 13619 |
24.09 |
| 2026-02-23 00:00 |
02:54:19.48 |
-00:39:11.5 |
HIP 13619 |
20.30 |
| 2026-02-23 12:00 |
02:54:30.79 |
-00:36:34.2 |
HIP 13619 |
16.51 |
| 2026-02-24 00:00 |
02:54:42.23 |
-00:33:56.8 |
HIP 13619 |
12.74 |