| 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 · University of Arizona 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) |
| 2026-09-20 00:00 |
11:57:01.79 |
-22:13:18.0 |
HIP 58178 |
15.57 |
| 2026-09-20 12:00 |
11:57:07.46 |
-22:13:56.6 |
HIP 58178 |
16.97 |
| 2026-09-21 00:00 |
11:57:13.13 |
-22:14:35.5 |
HIP 58298 |
17.73 |
| 2026-09-21 12:00 |
11:57:18.80 |
-22:15:14.7 |
HIP 58298 |
17.04 |
| 2026-09-22 00:00 |
11:57:24.47 |
-22:15:54.2 |
HIP 58298 |
16.44 |
| 2026-09-22 12:00 |
11:57:30.14 |
-22:16:34.0 |
HIP 58298 |
15.95 |
| 2026-09-23 00:00 |
11:57:35.81 |
-22:17:14.0 |
HIP 58298 |
15.57 |
| 2026-09-23 12:00 |
11:57:41.47 |
-22:17:54.4 |
HIP 58298 |
15.33 |
| 2026-09-24 00:00 |
11:57:47.13 |
-22:18:35.0 |
HIP 58298 |
15.22 |
| 2026-09-24 12:00 |
11:57:52.79 |
-22:19:15.9 |
HIP 58298 |
15.24 |
| 2026-09-25 00:00 |
11:57:58.45 |
-22:19:57.1 |
HIP 58298 |
15.41 |
| 2026-09-25 12:00 |
11:58:04.10 |
-22:20:38.5 |
HIP 58298 |
15.71 |
| 2026-09-26 00:00 |
11:58:09.75 |
-22:21:20.2 |
HIP 58298 |
16.13 |
| 2026-09-26 12:00 |
11:58:15.40 |
-22:22:02.2 |
HIP 58298 |
16.67 |
| 2026-09-27 00:00 |
11:58:21.04 |
-22:22:44.4 |
HIP 58298 |
17.32 |
| 2026-09-27 12:00 |
11:58:26.68 |
-22:23:26.9 |
HIP 58298 |
18.06 |
| 2026-09-28 00:00 |
11:58:32.31 |
-22:24:09.7 |
HIP 58298 |
18.89 |
| 2026-09-28 12:00 |
11:58:37.93 |
-22:24:52.7 |
HIP 58298 |
19.79 |
| 2026-09-29 00:00 |
11:58:43.55 |
-22:25:36.0 |
HIP 58298 |
20.76 |
| 2026-09-29 12:00 |
11:58:49.16 |
-22:26:19.6 |
HIP 58298 |
21.78 |
| 2026-09-30 00:00 |
11:58:54.77 |
-22:27:03.4 |
HIP 58298 |
22.85 |
| 2026-09-30 12:00 |
11:59:00.37 |
-22:27:47.4 |
HIP 58298 |
23.96 |
| 2026-10-01 00:00 |
11:59:05.96 |
-22:28:31.7 |
HIP 58298 |
25.11 |
| 2026-10-01 12:00 |
11:59:11.55 |
-22:29:16.3 |
HIP 58298 |
26.29 |
| 2026-10-02 00:00 |
11:59:17.13 |
-22:30:01.1 |
HIP 58298 |
27.49 |
| 2026-10-02 12:00 |
11:59:22.69 |
-22:30:46.1 |
HIP 58298 |
28.73 |
| 2026-10-03 00:00 |
11:59:28.25 |
-22:31:31.4 |
HIP 58298 |
29.98 |
| 2026-10-03 12:00 |
11:59:33.80 |
-22:32:16.9 |
HIP 58298 |
31.25 |
| 2026-10-04 00:00 |
11:59:39.34 |
-22:33:02.6 |
HIP 58298 |
32.53 |
| 2026-10-04 12:00 |
11:59:44.87 |
-22:33:48.6 |
HIP 58298 |
33.84 |
| 2026-10-05 00:00 |
11:59:50.39 |
-22:34:34.8 |
HIP 58298 |
35.15 |
| 2026-10-05 12:00 |
11:59:55.90 |
-22:35:21.3 |
HIP 58298 |
36.47 |
| 2026-10-06 00:00 |
12:00:01.40 |
-22:36:07.9 |
HIP 58298 |
37.81 |
| 2026-10-06 12:00 |
12:00:06.89 |
-22:36:54.8 |
HIP 58298 |
39.15 |
| 2026-10-07 00:00 |
12:00:12.36 |
-22:37:41.9 |
HIP 58298 |
40.50 |
| 2026-10-07 12:00 |
12:00:17.83 |
-22:38:29.3 |
HIP 58298 |
41.86 |
| 2026-10-08 00:00 |
12:00:23.27 |
-22:39:16.8 |
HIP 58298 |
43.22 |
| 2026-10-08 12:00 |
12:00:28.71 |
-22:40:04.6 |
HIP 58298 |
44.59 |
| 2026-10-09 00:00 |
12:00:34.13 |
-22:40:52.5 |
HIP 58298 |
45.97 |
| 2026-10-09 12:00 |
12:00:39.54 |
-22:41:40.7 |
HIP 58753 |
45.95 |
| 2026-10-10 00:00 |
12:00:44.93 |
-22:42:29.1 |
HIP 58753 |
45.67 |
| 2026-10-10 12:00 |
12:00:50.31 |
-22:43:17.7 |
HIP 58753 |
45.43 |
| 2026-10-11 00:00 |
12:00:55.67 |
-22:44:06.5 |
HIP 58753 |
45.25 |