| Parameter |
Value |
| Designation |
C/2022 W3 (Leonard) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2023-06-22T18:37:13.267200Z |
| Orbit solution date (soln_date, UTC) |
2024-02-01T00:43:16Z |
| Obs used |
876 |
| NEO |
- |
| M1 |
15.600 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2022-11-26T11:27:43.689600Z |
| Discovery magnitude (MPC) |
19.72 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2023-05-23.0000000 |
| e |
0.99503341 |
| q (au) |
1.397698 |
| a (au) |
281.420082 |
| i (deg) |
103.558036 |
| Ω (om, deg) |
132.268653 |
| ω (w, deg) |
116.521323 |
| M (ma, deg) |
359.993575 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.045 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.045 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.992 |
| 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 |
| 2022-11-13 |
2022-12-26 |
+10.0116 |
-4.536 |
| 2022-12-26 |
2023-02-14 |
+14.3184 |
-6.086 |
| 2023-02-14 |
2023-06-22 |
+4.7617 |
-2.428 |
| 2023-06-24 |
2023-09-10 |
+9.8993 |
-1.871 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
07:16:40.10 |
-82:23:35.8 |
HIP 36543 |
29.95 |
| 2026-07-29 12:00 |
07:18:04.13 |
-82:24:03.4 |
HIP 36543 |
27.41 |
| 2026-07-30 00:00 |
07:19:28.03 |
-82:24:31.3 |
HIP 36543 |
24.94 |
| 2026-07-30 12:00 |
07:20:51.80 |
-82:24:59.5 |
HIP 36543 |
22.57 |
| 2026-07-31 00:00 |
07:22:15.43 |
-82:25:28.0 |
HIP 36543 |
20.33 |
| 2026-07-31 12:00 |
07:23:38.93 |
-82:25:56.8 |
HIP 36543 |
18.27 |
| 2026-08-01 00:00 |
07:25:02.30 |
-82:26:25.8 |
HIP 36543 |
16.44 |
| 2026-08-01 12:00 |
07:26:25.53 |
-82:26:55.1 |
HIP 36543 |
14.94 |
| 2026-08-02 00:00 |
07:27:48.63 |
-82:27:24.8 |
HIP 36543 |
13.87 |
| 2026-08-02 12:00 |
07:29:11.60 |
-82:27:54.7 |
HIP 36543 |
13.31 |
| 2026-08-03 00:00 |
07:30:34.43 |
-82:28:24.9 |
HIP 36543 |
13.35 |
| 2026-08-03 12:00 |
07:31:57.13 |
-82:28:55.5 |
HIP 36543 |
13.96 |
| 2026-08-04 00:00 |
07:33:19.70 |
-82:29:26.3 |
HIP 37356 |
14.21 |
| 2026-08-04 12:00 |
07:34:42.13 |
-82:29:57.5 |
HIP 37356 |
11.55 |
| 2026-08-05 00:00 |
07:36:04.43 |
-82:30:29.0 |
HIP 37356 |
8.93 |
| 2026-08-05 12:00 |
07:37:26.59 |
-82:31:00.7 |
HIP 37356 |
6.41 |
| 2026-08-06 00:00 |
07:38:48.63 |
-82:31:32.9 |
HIP 37356 |
4.14 |
| 2026-08-06 12:00 |
07:40:10.52 |
-82:32:05.3 |
HIP 37356 |
2.82 |
| 2026-08-07 00:00 |
07:41:32.28 |
-82:32:38.1 |
HIP 37356 |
3.65 |
| 2026-08-07 12:00 |
07:42:53.91 |
-82:33:11.2 |
HIP 37356 |
5.76 |
| 2026-08-08 00:00 |
07:44:15.40 |
-82:33:44.6 |
HIP 37356 |
8.21 |
| 2026-08-08 12:00 |
07:45:36.76 |
-82:34:18.4 |
HIP 37356 |
10.77 |
| 2026-08-09 00:00 |
07:46:57.98 |
-82:34:52.5 |
HIP 37356 |
13.37 |
| 2026-08-09 12:00 |
07:48:19.06 |
-82:35:26.9 |
HIP 37356 |
15.98 |
| 2026-08-10 00:00 |
07:49:40.01 |
-82:36:01.8 |
HIP 37356 |
18.61 |
| 2026-08-10 12:00 |
07:51:00.81 |
-82:36:36.9 |
HIP 37356 |
21.23 |
| 2026-08-11 00:00 |
07:52:21.48 |
-82:37:12.4 |
HIP 37356 |
23.86 |
| 2026-08-11 12:00 |
07:53:42.01 |
-82:37:48.3 |
HIP 37356 |
26.48 |
| 2026-08-12 00:00 |
07:55:02.40 |
-82:38:24.5 |
HIP 37356 |
29.10 |
| 2026-08-12 12:00 |
07:56:22.66 |
-82:39:01.1 |
HIP 37356 |
31.71 |
| 2026-08-13 00:00 |
07:57:42.77 |
-82:39:38.1 |
HIP 37356 |
34.32 |
| 2026-08-13 12:00 |
07:59:02.74 |
-82:40:15.4 |
HIP 37356 |
36.92 |
| 2026-08-14 00:00 |
08:00:22.56 |
-82:40:53.1 |
HIP 37356 |
39.52 |
| 2026-08-14 12:00 |
08:01:42.25 |
-82:41:31.2 |
HIP 37356 |
42.11 |
| 2026-08-15 00:00 |
08:03:01.80 |
-82:42:09.6 |
HIP 39529 |
42.66 |
| 2026-08-15 12:00 |
08:04:21.20 |
-82:42:48.4 |
HIP 39529 |
43.18 |
| 2026-08-16 00:00 |
08:05:40.46 |
-82:43:27.6 |
HIP 39529 |
43.87 |
| 2026-08-16 12:00 |
08:06:59.58 |
-82:44:07.2 |
HIP 39529 |
44.71 |
| 2026-08-17 00:00 |
08:08:18.55 |
-82:44:47.1 |
HIP 39529 |
45.71 |
| 2026-08-17 12:00 |
08:09:37.39 |
-82:45:27.4 |
HIP 41910 |
44.91 |
| 2026-08-18 00:00 |
08:10:56.08 |
-82:46:08.1 |
HIP 41910 |
42.57 |
| 2026-08-18 12:00 |
08:12:14.63 |
-82:46:49.2 |
HIP 41910 |
40.27 |
| 2026-08-19 00:00 |
08:13:33.04 |
-82:47:30.7 |
HIP 41910 |
38.02 |