| Parameter |
Value |
| Designation |
138P/Shoemaker-Levy 7 |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-06-12T06:00:38.257920Z |
| Orbit solution date (soln_date, UTC) |
2026-03-31T14:13:33Z |
| Obs used |
134 |
| NEO |
- |
| M1 |
16.700 |
| K1 |
8.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2009-10-05.0000000 |
| e |
0.52978979 |
| q (au) |
1.703960 |
| a (au) |
3.623827 |
| i (deg) |
10.079832 |
| Ω (om, deg) |
309.438099 |
| ω (w, deg) |
95.552134 |
| M (ma, deg) |
219.804910 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.696 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.696 |
| n |
6.000 |
| gf |
0.961 |
| gb |
-0.835 |
| k |
0.991 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
05:03:42.51 |
+27:39:35.9 |
HIP 23570 |
8.70 |
| 2026-06-01 12:00 |
05:05:11.32 |
+27:40:24.9 |
HIP 23614 |
7.51 |
| 2026-06-02 00:00 |
05:06:40.05 |
+27:41:10.7 |
HIP 23614 |
27.04 |
| 2026-06-02 12:00 |
05:08:08.70 |
+27:41:53.4 |
HIP 24035 |
25.02 |
| 2026-06-03 00:00 |
05:09:37.25 |
+27:42:32.8 |
HIP 24035 |
6.53 |
| 2026-06-03 12:00 |
05:11:05.71 |
+27:43:09.1 |
HIP 24035 |
15.09 |
| 2026-06-04 00:00 |
05:12:34.08 |
+27:43:42.2 |
HIP 24304 |
5.45 |
| 2026-06-04 12:00 |
05:14:02.35 |
+27:44:12.1 |
HIP 24304 |
14.97 |
| 2026-06-05 00:00 |
05:15:30.52 |
+27:44:38.9 |
HIP 24579 |
13.56 |
| 2026-06-05 12:00 |
05:16:58.60 |
+27:45:02.6 |
HIP 24647 |
4.96 |
| 2026-06-06 00:00 |
05:18:26.58 |
+27:45:23.1 |
HIP 24647 |
14.59 |
| 2026-06-06 12:00 |
05:19:54.45 |
+27:45:40.5 |
HIP 24896 |
7.76 |
| 2026-06-07 00:00 |
05:21:22.22 |
+27:45:54.7 |
HIP 24984 |
12.59 |
| 2026-06-07 12:00 |
05:22:49.89 |
+27:46:05.9 |
HIP 25112 |
20.29 |
| 2026-06-08 00:00 |
05:24:17.45 |
+27:46:14.0 |
HIP 25112 |
30.15 |
| 2026-06-08 12:00 |
05:25:44.90 |
+27:46:19.0 |
HIP 25484 |
19.50 |
| 2026-06-09 00:00 |
05:27:12.24 |
+27:46:20.9 |
HIP 25484 |
10.03 |
| 2026-06-09 12:00 |
05:28:39.47 |
+27:46:19.7 |
HIP 25484 |
23.80 |
| 2026-06-10 00:00 |
05:30:06.58 |
+27:46:15.5 |
HIP 25871 |
16.85 |
| 2026-06-10 12:00 |
05:31:33.58 |
+27:46:08.3 |
HIP 25871 |
2.40 |
| 2026-06-11 00:00 |
05:33:00.46 |
+27:45:58.0 |
HIP 25871 |
21.62 |
| 2026-06-11 12:00 |
05:34:27.23 |
+27:45:44.7 |
HIP 26162 |
17.52 |
| 2026-06-12 00:00 |
05:35:53.87 |
+27:45:28.4 |
HIP 26291 |
5.74 |
| 2026-06-12 12:00 |
05:37:20.39 |
+27:45:09.1 |
HIP 26351 |
13.11 |
| 2026-06-13 00:00 |
05:38:46.79 |
+27:44:46.8 |
HIP 26708 |
29.66 |
| 2026-06-13 12:00 |
05:40:13.06 |
+27:44:21.5 |
HIP 26708 |
18.30 |
| 2026-06-14 00:00 |
05:41:39.21 |
+27:43:53.3 |
HIP 26852 |
5.69 |
| 2026-06-14 12:00 |
05:43:05.22 |
+27:43:22.2 |
HIP 26852 |
14.15 |
| 2026-06-15 00:00 |
05:44:31.11 |
+27:42:48.1 |
HIP 27063 |
2.45 |
| 2026-06-15 12:00 |
05:45:56.86 |
+27:42:11.0 |
HIP 27063 |
21.25 |
| 2026-06-16 00:00 |
05:47:22.47 |
+27:41:31.1 |
HIP 27456 |
27.49 |
| 2026-06-16 12:00 |
05:48:47.95 |
+27:40:48.3 |
HIP 27456 |
18.98 |
| 2026-06-17 00:00 |
05:50:13.30 |
+27:40:02.6 |
HIP 27613 |
7.80 |
| 2026-06-17 12:00 |
05:51:38.50 |
+27:39:14.0 |
HIP 27686 |
11.28 |
| 2026-06-18 00:00 |
05:53:03.56 |
+27:38:22.6 |
HIP 27830 |
3.92 |
| 2026-06-18 12:00 |
05:54:28.47 |
+27:37:28.3 |
HIP 27830 |
15.26 |
| 2026-06-19 00:00 |
05:55:53.25 |
+27:36:31.3 |
HIP 28033 |
7.03 |
| 2026-06-19 12:00 |
05:57:17.87 |
+27:35:31.4 |
HIP 28164 |
16.75 |
| 2026-06-20 00:00 |
05:58:42.35 |
+27:34:28.7 |
HIP 28327 |
5.22 |
| 2026-06-20 12:00 |
06:00:06.68 |
+27:33:23.2 |
HIP 28500 |
11.96 |
| 2026-06-21 00:00 |
06:01:30.86 |
+27:32:15.0 |
HIP 28500 |
7.06 |
| 2026-06-21 12:00 |
06:02:54.89 |
+27:31:04.0 |
HIP 28723 |
15.00 |
| 2026-06-22 00:00 |
06:04:18.76 |
+27:29:50.2 |
HIP 28723 |
5.90 |