C/2020 K3 (Leonard)
| 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) |
| 2026-02-03 00:00 |
12:13:48.03 |
-24:51:45.8 |
HIP 59563 |
12.70 |
| 2026-02-03 12:00 |
12:13:42.19 |
-24:51:57.7 |
HIP 59563 |
11.43 |
| 2026-02-04 00:00 |
12:13:36.29 |
-24:52:09.1 |
HIP 59563 |
10.16 |
| 2026-02-04 12:00 |
12:13:30.33 |
-24:52:20.0 |
HIP 59563 |
8.91 |
| 2026-02-05 00:00 |
12:13:24.33 |
-24:52:30.3 |
HIP 59563 |
7.68 |
| 2026-02-05 12:00 |
12:13:18.27 |
-24:52:40.1 |
HIP 59563 |
6.50 |
| 2026-02-06 00:00 |
12:13:12.16 |
-24:52:49.3 |
HIP 59563 |
5.39 |
| 2026-02-06 12:00 |
12:13:05.99 |
-24:52:58.0 |
HIP 59563 |
4.44 |
| 2026-02-07 00:00 |
12:12:59.78 |
-24:53:06.2 |
HIP 59563 |
3.76 |
| 2026-02-07 12:00 |
12:12:53.51 |
-24:53:13.8 |
HIP 59563 |
3.54 |
| 2026-02-08 00:00 |
12:12:47.19 |
-24:53:20.8 |
HIP 59563 |
3.87 |
| 2026-02-08 12:00 |
12:12:40.82 |
-24:53:27.3 |
HIP 59563 |
4.64 |
| 2026-02-09 00:00 |
12:12:34.40 |
-24:53:33.3 |
HIP 59563 |
5.69 |
| 2026-02-09 12:00 |
12:12:27.94 |
-24:53:38.7 |
HIP 59563 |
6.89 |
| 2026-02-10 00:00 |
12:12:21.42 |
-24:53:43.5 |
HIP 59563 |
8.18 |
| 2026-02-10 12:00 |
12:12:14.85 |
-24:53:47.8 |
HIP 59563 |
9.54 |
| 2026-02-11 00:00 |
12:12:08.24 |
-24:53:51.6 |
HIP 59563 |
10.94 |
| 2026-02-11 12:00 |
12:12:01.58 |
-24:53:54.8 |
HIP 59563 |
12.36 |
| 2026-02-12 00:00 |
12:11:54.87 |
-24:53:57.4 |
HIP 59563 |
13.82 |
| 2026-02-12 12:00 |
12:11:48.11 |
-24:53:59.5 |
HIP 59563 |
15.29 |
| 2026-02-13 00:00 |
12:11:41.31 |
-24:54:01.0 |
HIP 59563 |
16.79 |
| 2026-02-13 12:00 |
12:11:34.46 |
-24:54:01.9 |
HIP 59350 |
15.33 |
| 2026-02-14 00:00 |
12:11:27.56 |
-24:54:02.3 |
HIP 59350 |
13.81 |
| 2026-02-14 12:00 |
12:11:20.63 |
-24:54:02.2 |
HIP 59350 |
12.29 |
| 2026-02-15 00:00 |
12:11:13.64 |
-24:54:01.4 |
HIP 59350 |
10.79 |
| 2026-02-15 12:00 |
12:11:06.62 |
-24:54:00.2 |
HIP 59350 |
9.31 |
| 2026-02-16 00:00 |
12:10:59.55 |
-24:53:58.3 |
HIP 59350 |
7.86 |
| 2026-02-16 12:00 |
12:10:52.44 |
-24:53:55.9 |
HIP 59350 |
6.49 |
| 2026-02-17 00:00 |
12:10:45.28 |
-24:53:52.9 |
HIP 59350 |
5.25 |
| 2026-02-17 12:00 |
12:10:38.09 |
-24:53:49.4 |
HIP 59350 |
4.28 |
| 2026-02-18 00:00 |
12:10:30.85 |
-24:53:45.3 |
HIP 59350 |
3.81 |
| 2026-02-18 12:00 |
12:10:23.58 |
-24:53:40.7 |
HIP 59350 |
4.02 |
| 2026-02-19 00:00 |
12:10:16.26 |
-24:53:35.5 |
HIP 59350 |
4.84 |
| 2026-02-19 12:00 |
12:10:08.91 |
-24:53:29.7 |
HIP 59350 |
6.02 |
| 2026-02-20 00:00 |
12:10:01.52 |
-24:53:23.4 |
HIP 59350 |
7.41 |
| 2026-02-20 12:00 |
12:09:54.09 |
-24:53:16.5 |
HIP 59350 |
8.91 |
| 2026-02-21 00:00 |
12:09:46.62 |
-24:53:09.0 |
HIP 59350 |
10.48 |
| 2026-02-21 12:00 |
12:09:39.12 |
-24:53:01.0 |
HIP 59350 |
12.10 |
| 2026-02-22 00:00 |
12:09:31.58 |
-24:52:52.5 |
HIP 59350 |
13.75 |
| 2026-02-22 12:00 |
12:09:24.01 |
-24:52:43.4 |
HIP 59350 |
15.42 |
| 2026-02-23 00:00 |
12:09:16.40 |
-24:52:33.7 |
HIP 59199 |
14.68 |
| 2026-02-23 12:00 |
12:09:08.76 |
-24:52:23.5 |
HIP 59199 |
13.22 |
| 2026-02-24 00:00 |
12:09:01.08 |
-24:52:12.7 |
HIP 59199 |
11.83 |