| 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) |
| 2026-05-12 00:00 |
11:49:38.99 |
-23:05:03.4 |
HIP 57697 |
4.93 |
| 2026-05-12 12:00 |
11:49:34.00 |
-23:04:08.5 |
HIP 57697 |
5.60 |
| 2026-05-13 00:00 |
11:49:29.06 |
-23:03:13.7 |
HIP 57697 |
6.52 |
| 2026-05-13 12:00 |
11:49:24.18 |
-23:02:19.0 |
HIP 57697 |
7.60 |
| 2026-05-14 00:00 |
11:49:19.36 |
-23:01:24.4 |
HIP 57697 |
8.77 |
| 2026-05-14 12:00 |
11:49:14.59 |
-23:00:29.9 |
HIP 57697 |
10.00 |
| 2026-05-15 00:00 |
11:49:09.88 |
-22:59:35.6 |
HIP 57697 |
11.27 |
| 2026-05-15 12:00 |
11:49:05.23 |
-22:58:41.3 |
HIP 57594 |
11.16 |
| 2026-05-16 00:00 |
11:49:00.64 |
-22:57:47.2 |
HIP 57594 |
10.94 |
| 2026-05-16 12:00 |
11:48:56.10 |
-22:56:53.2 |
HIP 57594 |
10.91 |
| 2026-05-17 00:00 |
11:48:51.62 |
-22:55:59.3 |
HIP 57594 |
11.06 |
| 2026-05-17 12:00 |
11:48:47.20 |
-22:55:05.6 |
HIP 57594 |
11.38 |
| 2026-05-18 00:00 |
11:48:42.84 |
-22:54:12.0 |
HIP 57594 |
11.84 |
| 2026-05-18 12:00 |
11:48:38.54 |
-22:53:18.6 |
HIP 57594 |
12.43 |
| 2026-05-19 00:00 |
11:48:34.29 |
-22:52:25.3 |
HIP 57594 |
13.13 |
| 2026-05-19 12:00 |
11:48:30.11 |
-22:51:32.2 |
HIP 57594 |
13.92 |
| 2026-05-20 00:00 |
11:48:25.98 |
-22:50:39.3 |
HIP 57594 |
14.78 |
| 2026-05-20 12:00 |
11:48:21.91 |
-22:49:46.5 |
HIP 57594 |
15.70 |
| 2026-05-21 00:00 |
11:48:17.91 |
-22:48:53.9 |
HIP 57594 |
16.66 |
| 2026-05-21 12:00 |
11:48:13.96 |
-22:48:01.5 |
HIP 57594 |
17.66 |
| 2026-05-22 00:00 |
11:48:10.07 |
-22:47:09.2 |
HIP 57594 |
18.68 |
| 2026-05-22 12:00 |
11:48:06.24 |
-22:46:17.2 |
HIP 57594 |
19.72 |
| 2026-05-23 00:00 |
11:48:02.47 |
-22:45:25.3 |
HIP 57594 |
20.77 |
| 2026-05-23 12:00 |
11:47:58.76 |
-22:44:33.7 |
HIP 57594 |
21.84 |
| 2026-05-24 00:00 |
11:47:55.11 |
-22:43:42.2 |
HIP 57594 |
22.91 |
| 2026-05-24 12:00 |
11:47:51.52 |
-22:42:51.0 |
HIP 57594 |
23.99 |
| 2026-05-25 00:00 |
11:47:47.99 |
-22:42:00.0 |
HIP 57594 |
25.07 |
| 2026-05-25 12:00 |
11:47:44.52 |
-22:41:09.1 |
HIP 57594 |
26.15 |
| 2026-05-26 00:00 |
11:47:41.12 |
-22:40:18.5 |
HIP 57594 |
27.23 |
| 2026-05-26 12:00 |
11:47:37.77 |
-22:39:28.1 |
HIP 57594 |
28.30 |
| 2026-05-27 00:00 |
11:47:34.48 |
-22:38:37.9 |
HIP 57594 |
29.37 |
| 2026-05-27 12:00 |
11:47:31.25 |
-22:37:47.9 |
HIP 57437 |
30.10 |
| 2026-05-28 00:00 |
11:47:28.08 |
-22:36:58.2 |
HIP 57437 |
30.50 |
| 2026-05-28 12:00 |
11:47:24.97 |
-22:36:08.8 |
HIP 57583 |
30.81 |
| 2026-05-29 00:00 |
11:47:21.93 |
-22:35:19.5 |
HIP 57583 |
30.33 |
| 2026-05-29 12:00 |
11:47:18.94 |
-22:34:30.5 |
HIP 57583 |
29.88 |
| 2026-05-30 00:00 |
11:47:16.01 |
-22:33:41.8 |
HIP 57583 |
29.46 |
| 2026-05-30 12:00 |
11:47:13.14 |
-22:32:53.3 |
HIP 57583 |
29.07 |
| 2026-05-31 00:00 |
11:47:10.34 |
-22:32:05.0 |
HIP 57583 |
28.70 |
| 2026-05-31 12:00 |
11:47:07.59 |
-22:31:17.0 |
HIP 57583 |
28.37 |
| 2026-06-01 00:00 |
11:47:04.91 |
-22:30:29.3 |
HIP 57583 |
28.06 |
| 2026-06-01 12:00 |
11:47:02.28 |
-22:29:41.8 |
HIP 57343 |
27.11 |
| 2026-06-02 00:00 |
11:46:59.72 |
-22:28:54.6 |
HIP 57343 |
26.17 |