| Parameter |
Value |
| Designation |
P/2021 L2 (Leonard) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-07-24T13:05:37.386240Z |
| Orbit solution date (soln_date, UTC) |
2021-11-20T19:13:06Z |
| Obs used |
131 |
| NEO |
- |
| M1 |
16.200 |
| K1 |
11.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2021-06-08T09:29:49.689600Z |
| Discovery magnitude (MPC) |
20.31 G |
| Discovery observatory (MPC) |
G96 · Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-07-26.0000000 |
| e |
0.52175163 |
| q (au) |
1.938550 |
| a (au) |
4.053438 |
| i (deg) |
21.068982 |
| Ω (om, deg) |
266.675736 |
| ω (w, deg) |
51.538655 |
| M (ma, deg) |
0.175655 |
Magnitude
Scatter + Global Linear
$$
M_a = (18.490 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
18.490 |
| n |
2.000 |
| gf |
0.848 |
| gb |
-1.000 |
| k |
0.965 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
09:00:46.73 |
-04:49:29.4 |
HIP 44173 |
14.49 |
| 2026-03-26 12:00 |
09:00:38.73 |
-04:47:46.5 |
HIP 44173 |
12.32 |
| 2026-03-27 00:00 |
09:00:30.88 |
-04:46:03.7 |
HIP 44173 |
10.40 |
| 2026-03-27 12:00 |
09:00:23.20 |
-04:44:21.1 |
HIP 44173 |
8.88 |
| 2026-03-28 00:00 |
09:00:15.68 |
-04:42:38.7 |
HIP 44173 |
7.95 |
| 2026-03-28 12:00 |
09:00:08.32 |
-04:40:56.4 |
HIP 44173 |
7.79 |
| 2026-03-29 00:00 |
09:00:01.13 |
-04:39:14.4 |
HIP 44173 |
8.42 |
| 2026-03-29 12:00 |
08:59:54.10 |
-04:37:32.5 |
HIP 44173 |
9.66 |
| 2026-03-30 00:00 |
08:59:47.24 |
-04:35:50.9 |
HIP 44173 |
11.30 |
| 2026-03-30 12:00 |
08:59:40.53 |
-04:34:09.6 |
HIP 44173 |
13.16 |
| 2026-03-31 00:00 |
08:59:34.00 |
-04:32:28.5 |
HIP 44173 |
15.15 |
| 2026-03-31 12:00 |
08:59:27.63 |
-04:30:47.6 |
HIP 44173 |
17.21 |
| 2026-04-01 00:00 |
08:59:21.42 |
-04:29:07.0 |
HIP 44173 |
19.31 |
| 2026-04-01 12:00 |
08:59:15.38 |
-04:27:26.8 |
HIP 44173 |
21.43 |
| 2026-04-02 00:00 |
08:59:09.51 |
-04:25:46.8 |
HIP 44173 |
23.55 |
| 2026-04-02 12:00 |
08:59:03.81 |
-04:24:07.1 |
HIP 44124 |
22.65 |
| 2026-04-03 00:00 |
08:58:58.27 |
-04:22:27.8 |
HIP 44124 |
21.14 |
| 2026-04-03 12:00 |
08:58:52.89 |
-04:20:48.7 |
HIP 44124 |
19.75 |
| 2026-04-04 00:00 |
08:58:47.69 |
-04:19:10.1 |
HIP 44124 |
18.49 |
| 2026-04-04 12:00 |
08:58:42.65 |
-04:17:31.8 |
HIP 44124 |
17.39 |
| 2026-04-05 00:00 |
08:58:37.78 |
-04:15:53.8 |
HIP 44124 |
16.45 |
| 2026-04-05 12:00 |
08:58:33.08 |
-04:14:16.2 |
HIP 44124 |
15.71 |
| 2026-04-06 00:00 |
08:58:28.55 |
-04:12:39.1 |
HIP 44124 |
15.17 |
| 2026-04-06 12:00 |
08:58:24.18 |
-04:11:02.3 |
HIP 44124 |
14.85 |
| 2026-04-07 00:00 |
08:58:19.98 |
-04:09:25.9 |
HIP 44124 |
14.75 |
| 2026-04-07 12:00 |
08:58:15.96 |
-04:07:50.0 |
HIP 44124 |
14.86 |
| 2026-04-08 00:00 |
08:58:12.10 |
-04:06:14.5 |
HIP 44124 |
15.17 |
| 2026-04-08 12:00 |
08:58:08.41 |
-04:04:39.4 |
HIP 44124 |
15.65 |
| 2026-04-09 00:00 |
08:58:04.89 |
-04:03:04.8 |
HIP 44124 |
16.29 |
| 2026-04-09 12:00 |
08:58:01.54 |
-04:01:30.6 |
HIP 44124 |
17.05 |
| 2026-04-10 00:00 |
08:57:58.35 |
-03:59:57.0 |
HIP 44124 |
17.91 |
| 2026-04-10 12:00 |
08:57:55.34 |
-03:58:23.8 |
HIP 44124 |
18.86 |
| 2026-04-11 00:00 |
08:57:52.50 |
-03:56:51.1 |
HIP 44124 |
19.86 |
| 2026-04-11 12:00 |
08:57:49.83 |
-03:55:18.9 |
HIP 44124 |
20.92 |
| 2026-04-12 00:00 |
08:57:47.32 |
-03:53:47.2 |
HIP 44038 |
19.61 |
| 2026-04-12 12:00 |
08:57:44.99 |
-03:52:16.1 |
HIP 44038 |
18.28 |
| 2026-04-13 00:00 |
08:57:42.82 |
-03:50:45.5 |
HIP 44038 |
17.00 |
| 2026-04-13 12:00 |
08:57:40.83 |
-03:49:15.4 |
HIP 44038 |
15.78 |
| 2026-04-14 00:00 |
08:57:39.00 |
-03:47:45.9 |
HIP 44038 |
14.61 |
| 2026-04-14 12:00 |
08:57:37.35 |
-03:46:17.0 |
HIP 44038 |
13.50 |
| 2026-04-15 00:00 |
08:57:35.86 |
-03:44:48.6 |
HIP 44038 |
12.47 |
| 2026-04-15 12:00 |
08:57:34.54 |
-03:43:20.9 |
HIP 44038 |
11.53 |
| 2026-04-16 00:00 |
08:57:33.40 |
-03:41:53.7 |
HIP 44038 |
10.69 |