| Parameter |
Value |
| Designation |
396P/Leonard |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2019-08-29T03:15:14.060160Z |
| Orbit solution date (soln_date, UTC) |
2023-04-24T23:29:36Z |
| Obs used |
115 |
| NEO |
- |
| M1 |
15.700 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2018-05-09.0000000 |
| e |
0.41780395 |
| q (au) |
3.983116 |
| a (au) |
6.841537 |
| i (deg) |
5.434040 |
| Ω (om, deg) |
136.663398 |
| ω (w, deg) |
8.678978 |
| M (ma, deg) |
333.720604 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.411 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.411 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.855 |
| k |
0.998 |
| 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) |
| 2026-09-20 00:00 |
20:20:35.51 |
-18:37:23.6 |
HIP 100348 |
18.97 |
| 2026-09-20 12:00 |
20:20:31.20 |
-18:37:45.5 |
HIP 100348 |
19.66 |
| 2026-09-21 00:00 |
20:20:27.00 |
-18:38:07.0 |
HIP 100348 |
20.37 |
| 2026-09-21 12:00 |
20:20:22.90 |
-18:38:28.2 |
HIP 100348 |
21.09 |
| 2026-09-22 00:00 |
20:20:18.90 |
-18:38:49.1 |
HIP 100348 |
21.83 |
| 2026-09-22 12:00 |
20:20:15.01 |
-18:39:09.6 |
HIP 100348 |
22.56 |
| 2026-09-23 00:00 |
20:20:11.22 |
-18:39:29.7 |
HIP 100348 |
23.30 |
| 2026-09-23 12:00 |
20:20:07.53 |
-18:39:49.5 |
HIP 100348 |
24.04 |
| 2026-09-24 00:00 |
20:20:03.96 |
-18:40:08.9 |
HIP 100348 |
24.77 |
| 2026-09-24 12:00 |
20:20:00.48 |
-18:40:27.9 |
HIP 100348 |
25.49 |
| 2026-09-25 00:00 |
20:19:57.12 |
-18:40:46.7 |
HIP 100348 |
26.20 |
| 2026-09-25 12:00 |
20:19:53.86 |
-18:41:05.0 |
HIP 100348 |
26.90 |
| 2026-09-26 00:00 |
20:19:50.70 |
-18:41:23.0 |
HIP 100195 |
26.51 |
| 2026-09-26 12:00 |
20:19:47.66 |
-18:41:40.6 |
HIP 100195 |
26.06 |
| 2026-09-27 00:00 |
20:19:44.72 |
-18:41:57.9 |
HIP 100195 |
25.64 |
| 2026-09-27 12:00 |
20:19:41.89 |
-18:42:14.8 |
HIP 100195 |
25.24 |
| 2026-09-28 00:00 |
20:19:39.16 |
-18:42:31.4 |
HIP 100195 |
24.86 |
| 2026-09-28 12:00 |
20:19:36.54 |
-18:42:47.6 |
HIP 100195 |
24.51 |
| 2026-09-29 00:00 |
20:19:34.03 |
-18:43:03.4 |
HIP 100195 |
24.18 |
| 2026-09-29 12:00 |
20:19:31.63 |
-18:43:18.9 |
HIP 100195 |
23.87 |
| 2026-09-30 00:00 |
20:19:29.34 |
-18:43:34.0 |
HIP 100195 |
23.58 |
| 2026-09-30 12:00 |
20:19:27.16 |
-18:43:48.7 |
HIP 100195 |
23.31 |
| 2026-10-01 00:00 |
20:19:25.08 |
-18:44:03.1 |
HIP 100195 |
23.06 |
| 2026-10-01 12:00 |
20:19:23.12 |
-18:44:17.1 |
HIP 100195 |
22.83 |
| 2026-10-02 00:00 |
20:19:21.26 |
-18:44:30.8 |
HIP 100195 |
22.60 |
| 2026-10-02 12:00 |
20:19:19.51 |
-18:44:44.0 |
HIP 100195 |
22.40 |
| 2026-10-03 00:00 |
20:19:17.88 |
-18:44:57.0 |
HIP 100195 |
22.20 |
| 2026-10-03 12:00 |
20:19:16.35 |
-18:45:09.5 |
HIP 100195 |
22.02 |
| 2026-10-04 00:00 |
20:19:14.93 |
-18:45:21.7 |
HIP 100195 |
21.85 |
| 2026-10-04 12:00 |
20:19:13.63 |
-18:45:33.5 |
HIP 100195 |
21.68 |
| 2026-10-05 00:00 |
20:19:12.43 |
-18:45:44.9 |
HIP 100195 |
21.52 |
| 2026-10-05 12:00 |
20:19:11.35 |
-18:45:56.0 |
HIP 100195 |
21.37 |
| 2026-10-06 00:00 |
20:19:10.38 |
-18:46:06.7 |
HIP 100195 |
21.23 |
| 2026-10-06 12:00 |
20:19:09.52 |
-18:46:17.0 |
HIP 100195 |
21.09 |
| 2026-10-07 00:00 |
20:19:08.77 |
-18:46:26.9 |
HIP 100195 |
20.96 |
| 2026-10-07 12:00 |
20:19:08.13 |
-18:46:36.5 |
HIP 100195 |
20.83 |
| 2026-10-08 00:00 |
20:19:07.60 |
-18:46:45.7 |
HIP 100195 |
20.70 |
| 2026-10-08 12:00 |
20:19:07.18 |
-18:46:54.5 |
HIP 100195 |
20.57 |
| 2026-10-09 00:00 |
20:19:06.88 |
-18:47:02.9 |
HIP 100195 |
20.45 |
| 2026-10-09 12:00 |
20:19:06.69 |
-18:47:11.0 |
HIP 100195 |
20.32 |
| 2026-10-10 00:00 |
20:19:06.61 |
-18:47:18.6 |
HIP 100195 |
20.20 |
| 2026-10-10 12:00 |
20:19:06.64 |
-18:47:25.9 |
HIP 100195 |
20.08 |
| 2026-10-11 00:00 |
20:19:06.79 |
-18:47:32.9 |
HIP 100195 |
19.96 |