| Parameter |
Value |
| Designation |
C/2020 K3 (Leonard) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-05-30T02:55:42.355200Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:34:07Z |
| Obs used |
212 |
| NEO |
- |
| M1 |
14.900 |
| K1 |
13.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2020-05-22T10:46:25.824000Z |
| Discovery magnitude (MPC) |
18.00 G |
| Discovery observatory (MPC) |
703 · Catalina Sky Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-06-08.0000000 |
| e |
0.99242187 |
| q (au) |
1.593446 |
| a (au) |
210.269034 |
| i (deg) |
128.715444 |
| Ω (om, deg) |
27.927767 |
| ω (w, deg) |
62.697775 |
| M (ma, deg) |
0.002870 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.248 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.248 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.656 |
| k |
0.800 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2019-10-25 |
2020-05-29 |
+3.6819 |
-1.535 |
| 2020-05-31 |
2020-09-12 |
+12.6466 |
-2.959 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
12:00:45.29 |
-24:25:44.1 |
HIP 58559 |
4.27 |
| 2026-03-26 12:00 |
12:00:36.88 |
-24:25:03.5 |
HIP 58559 |
3.13 |
| 2026-03-27 00:00 |
12:00:28.47 |
-24:24:22.6 |
HIP 58559 |
3.11 |
| 2026-03-27 12:00 |
12:00:20.08 |
-24:23:41.3 |
HIP 58559 |
4.22 |
| 2026-03-28 00:00 |
12:00:11.70 |
-24:22:59.6 |
HIP 58559 |
5.85 |
| 2026-03-28 12:00 |
12:00:03.34 |
-24:22:17.6 |
HIP 58559 |
7.68 |
| 2026-03-29 00:00 |
11:59:54.98 |
-24:21:35.1 |
HIP 58559 |
9.59 |
| 2026-03-29 12:00 |
11:59:46.64 |
-24:20:52.4 |
HIP 58559 |
11.54 |
| 2026-03-30 00:00 |
11:59:38.31 |
-24:20:09.2 |
HIP 58559 |
13.52 |
| 2026-03-30 12:00 |
11:59:30.00 |
-24:19:25.7 |
HIP 58559 |
15.51 |
| 2026-03-31 00:00 |
11:59:21.70 |
-24:18:41.9 |
HIP 58559 |
17.51 |
| 2026-03-31 12:00 |
11:59:13.42 |
-24:17:57.7 |
HIP 58559 |
19.51 |
| 2026-04-01 00:00 |
11:59:05.15 |
-24:17:13.2 |
HIP 58559 |
21.52 |
| 2026-04-01 12:00 |
11:58:56.91 |
-24:16:28.3 |
HIP 58374 |
23.43 |
| 2026-04-02 00:00 |
11:58:48.68 |
-24:15:43.1 |
HIP 58374 |
21.97 |
| 2026-04-02 12:00 |
11:58:40.47 |
-24:14:57.6 |
HIP 58374 |
20.60 |
| 2026-04-03 00:00 |
11:58:32.27 |
-24:14:11.7 |
HIP 58374 |
19.34 |
| 2026-04-03 12:00 |
11:58:24.10 |
-24:13:25.6 |
HIP 58374 |
18.22 |
| 2026-04-04 00:00 |
11:58:15.95 |
-24:12:39.1 |
HIP 58374 |
17.25 |
| 2026-04-04 12:00 |
11:58:07.82 |
-24:11:52.3 |
HIP 58374 |
16.47 |
| 2026-04-05 00:00 |
11:57:59.71 |
-24:11:05.2 |
HIP 58374 |
15.90 |
| 2026-04-05 12:00 |
11:57:51.62 |
-24:10:17.8 |
HIP 58374 |
15.57 |
| 2026-04-06 00:00 |
11:57:43.56 |
-24:09:30.2 |
HIP 58374 |
15.49 |
| 2026-04-06 12:00 |
11:57:35.51 |
-24:08:42.2 |
HIP 58374 |
15.65 |
| 2026-04-07 00:00 |
11:57:27.50 |
-24:07:53.9 |
HIP 58374 |
16.06 |
| 2026-04-07 12:00 |
11:57:19.50 |
-24:07:05.4 |
HIP 58374 |
16.70 |
| 2026-04-08 00:00 |
11:57:11.54 |
-24:06:16.6 |
HIP 58374 |
17.53 |
| 2026-04-08 12:00 |
11:57:03.60 |
-24:05:27.5 |
HIP 58374 |
18.53 |
| 2026-04-09 00:00 |
11:56:55.68 |
-24:04:38.1 |
HIP 58374 |
19.68 |
| 2026-04-09 12:00 |
11:56:47.79 |
-24:03:48.5 |
HIP 58374 |
20.94 |
| 2026-04-10 00:00 |
11:56:39.93 |
-24:02:58.6 |
HIP 58374 |
22.30 |
| 2026-04-10 12:00 |
11:56:32.10 |
-24:02:08.5 |
HIP 58374 |
23.75 |
| 2026-04-11 00:00 |
11:56:24.30 |
-24:01:18.1 |
HIP 58374 |
25.25 |
| 2026-04-11 12:00 |
11:56:16.52 |
-24:00:27.5 |
HIP 58374 |
26.81 |
| 2026-04-12 00:00 |
11:56:08.78 |
-23:59:36.7 |
HIP 58374 |
28.42 |
| 2026-04-12 12:00 |
11:56:01.07 |
-23:58:45.6 |
HIP 58374 |
30.06 |
| 2026-04-13 00:00 |
11:55:53.39 |
-23:57:54.3 |
HIP 58089 |
29.02 |
| 2026-04-13 12:00 |
11:55:45.74 |
-23:57:02.8 |
HIP 58089 |
27.40 |
| 2026-04-14 00:00 |
11:55:38.12 |
-23:56:11.0 |
HIP 58089 |
25.83 |
| 2026-04-14 12:00 |
11:55:30.54 |
-23:55:19.1 |
HIP 58089 |
24.32 |
| 2026-04-15 00:00 |
11:55:22.99 |
-23:54:26.9 |
HIP 58089 |
22.87 |
| 2026-04-15 12:00 |
11:55:15.47 |
-23:53:34.6 |
HIP 58089 |
21.49 |
| 2026-04-16 00:00 |
11:55:07.99 |
-23:52:42.1 |
HIP 58089 |
20.20 |