P/2021 L2 (Leonard)
| 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) |
| 2026-02-03 00:00 |
09:24:28.27 |
-07:10:32.5 |
HIP 46044 |
33.78 |
| 2026-02-03 12:00 |
09:24:11.81 |
-07:09:54.2 |
HIP 46044 |
32.64 |
| 2026-02-04 00:00 |
09:23:55.32 |
-07:09:14.6 |
HIP 46044 |
32.02 |
| 2026-02-04 12:00 |
09:23:38.81 |
-07:08:33.8 |
HIP 46044 |
31.94 |
| 2026-02-05 00:00 |
09:23:22.27 |
-07:07:51.7 |
HIP 46044 |
32.43 |
| 2026-02-05 12:00 |
09:23:05.72 |
-07:07:08.4 |
HIP 46044 |
33.45 |
| 2026-02-06 00:00 |
09:22:49.14 |
-07:06:23.8 |
HIP 45887 |
33.74 |
| 2026-02-06 12:00 |
09:22:32.56 |
-07:05:38.0 |
HIP 45887 |
30.65 |
| 2026-02-07 00:00 |
09:22:15.96 |
-07:04:50.9 |
HIP 45887 |
27.84 |
| 2026-02-07 12:00 |
09:21:59.35 |
-07:04:02.6 |
HIP 45887 |
25.38 |
| 2026-02-08 00:00 |
09:21:42.73 |
-07:03:13.1 |
HIP 45887 |
23.41 |
| 2026-02-08 12:00 |
09:21:26.11 |
-07:02:22.4 |
HIP 45887 |
22.06 |
| 2026-02-09 00:00 |
09:21:09.49 |
-07:01:30.5 |
HIP 45887 |
21.44 |
| 2026-02-09 12:00 |
09:20:52.86 |
-07:00:37.5 |
HIP 45887 |
21.61 |
| 2026-02-10 00:00 |
09:20:36.24 |
-06:59:43.2 |
HIP 45887 |
22.58 |
| 2026-02-10 12:00 |
09:20:19.62 |
-06:58:47.7 |
HIP 45887 |
24.23 |
| 2026-02-11 00:00 |
09:20:03.01 |
-06:57:51.1 |
HIP 45887 |
26.45 |
| 2026-02-11 12:00 |
09:19:46.41 |
-06:56:53.4 |
HIP 45887 |
29.11 |
| 2026-02-12 00:00 |
09:19:29.82 |
-06:55:54.5 |
HIP 45887 |
32.09 |
| 2026-02-12 12:00 |
09:19:13.25 |
-06:54:54.5 |
HIP 45887 |
35.32 |
| 2026-02-13 00:00 |
09:18:56.69 |
-06:53:53.3 |
HIP 45530 |
34.98 |
| 2026-02-13 12:00 |
09:18:40.15 |
-06:52:51.1 |
HIP 45530 |
30.76 |
| 2026-02-14 00:00 |
09:18:23.64 |
-06:51:47.7 |
HIP 45530 |
26.54 |
| 2026-02-14 12:00 |
09:18:07.14 |
-06:50:43.3 |
HIP 45530 |
22.32 |
| 2026-02-15 00:00 |
09:17:50.68 |
-06:49:37.7 |
HIP 45530 |
18.12 |
| 2026-02-15 12:00 |
09:17:34.25 |
-06:48:31.2 |
HIP 45530 |
13.92 |
| 2026-02-16 00:00 |
09:17:17.85 |
-06:47:23.5 |
HIP 45530 |
9.76 |
| 2026-02-16 12:00 |
09:17:01.48 |
-06:46:14.9 |
HIP 45530 |
5.68 |
| 2026-02-17 00:00 |
09:16:45.15 |
-06:45:05.2 |
HIP 45530 |
2.22 |
| 2026-02-17 12:00 |
09:16:28.86 |
-06:43:54.5 |
HIP 45530 |
3.61 |
| 2026-02-18 00:00 |
09:16:12.61 |
-06:42:42.8 |
HIP 45530 |
7.51 |
| 2026-02-18 12:00 |
09:15:56.41 |
-06:41:30.1 |
HIP 45530 |
11.62 |
| 2026-02-19 00:00 |
09:15:40.25 |
-06:40:16.5 |
HIP 45530 |
15.77 |
| 2026-02-19 12:00 |
09:15:24.14 |
-06:39:01.9 |
HIP 45530 |
19.93 |
| 2026-02-20 00:00 |
09:15:08.09 |
-06:37:46.4 |
HIP 45530 |
24.09 |
| 2026-02-20 12:00 |
09:14:52.09 |
-06:36:29.9 |
HIP 45530 |
28.25 |
| 2026-02-21 00:00 |
09:14:36.15 |
-06:35:12.6 |
HIP 45530 |
32.40 |
| 2026-02-21 12:00 |
09:14:20.26 |
-06:33:54.3 |
HIP 45180 |
36.00 |
| 2026-02-22 00:00 |
09:14:04.44 |
-06:32:35.2 |
HIP 45180 |
33.86 |
| 2026-02-22 12:00 |
09:13:48.68 |
-06:31:15.2 |
HIP 45180 |
32.14 |
| 2026-02-23 00:00 |
09:13:32.99 |
-06:29:54.3 |
HIP 45180 |
30.90 |
| 2026-02-23 12:00 |
09:13:17.36 |
-06:28:32.6 |
HIP 45180 |
30.20 |
| 2026-02-24 00:00 |
09:13:01.81 |
-06:27:10.1 |
HIP 45180 |
30.07 |