C/2022 R3 (Leonard)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2022 R3 (Leonard) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2023-03-05T07:22:22.114560Z |
| Orbit solution date (soln_date, UTC) | 2025-04-11T14:44:29Z |
| Obs used | 355 |
| NEO | - |
| M1 | 12.300 |
| K1 | 4.500 |
| PC | - |
| Discovery observation (MPC, UTC) | 2022-09-15T08:35:14.697600Z |
| Discovery magnitude (MPC) | 18.96 G |
| Discovery observatory (MPC) | G96 · University of Arizona Mt. Lemmon Survey |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2023-08-01.0000000 |
| e | 1.00075876 |
| q (au) | 5.128952 |
| a (au) | -6759.666695 |
| i (deg) | 43.082904 |
| Ω (om, deg) | 8.238598 |
| ω (w, deg) | 72.866685 |
| M (ma, deg) | 0.000264 |
Magnitude
Scatter + Global Linear
$$ M_a = (16.040 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 16.040 |
| n | 2.000 |
| gf | 1.000 |
| gb | -0.844 |
| 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 |
|---|---|---|---|
| 2023-08-17 | 2024-05-13 | -12.5844 | +9.340 |
| 2024-05-13 | 2026-02-25 | -19.7422 | +16.108 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Finding Chart
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-09-20 00:00 | 12:02:09.59 | +10:53:31.0 | HIP 58652 | 13.07 |
| 2026-09-20 12:00 | 12:02:20.63 | +10:51:45.8 | HIP 58652 | 16.11 |
| 2026-09-21 00:00 | 12:02:31.66 | +10:50:00.9 | HIP 58652 | 19.21 |
| 2026-09-21 12:00 | 12:02:42.69 | +10:48:16.2 | HIP 58652 | 22.35 |
| 2026-09-22 00:00 | 12:02:53.72 | +10:46:31.7 | HIP 58652 | 25.50 |
| 2026-09-22 12:00 | 12:03:04.75 | +10:44:47.6 | HIP 58652 | 28.66 |
| 2026-09-23 00:00 | 12:03:15.77 | +10:43:03.7 | HIP 58652 | 31.83 |
| 2026-09-23 12:00 | 12:03:26.78 | +10:41:20.0 | HIP 58968 | 33.81 |
| 2026-09-24 00:00 | 12:03:37.79 | +10:39:36.6 | HIP 58968 | 32.40 |
| 2026-09-24 12:00 | 12:03:48.80 | +10:37:53.5 | HIP 58968 | 31.25 |
| 2026-09-25 00:00 | 12:03:59.80 | +10:36:10.6 | HIP 58968 | 30.39 |
| 2026-09-25 12:00 | 12:04:10.79 | +10:34:28.0 | HIP 59025 | 28.87 |
| 2026-09-26 00:00 | 12:04:21.77 | +10:32:45.7 | HIP 59025 | 25.92 |
| 2026-09-26 12:00 | 12:04:32.75 | +10:31:03.6 | HIP 59025 | 23.04 |
| 2026-09-27 00:00 | 12:04:43.72 | +10:29:21.8 | HIP 59025 | 20.25 |
| 2026-09-27 12:00 | 12:04:54.68 | +10:27:40.3 | HIP 59025 | 17.60 |
| 2026-09-28 00:00 | 12:05:05.64 | +10:25:59.1 | HIP 59025 | 15.15 |
| 2026-09-28 12:00 | 12:05:16.58 | +10:24:18.2 | HIP 59025 | 13.02 |
| 2026-09-29 00:00 | 12:05:27.51 | +10:22:37.5 | HIP 59025 | 11.39 |
| 2026-09-29 12:00 | 12:05:38.44 | +10:20:57.1 | HIP 59025 | 10.48 |
| 2026-09-30 00:00 | 12:05:49.35 | +10:19:17.1 | HIP 59025 | 10.49 |
| 2026-09-30 12:00 | 12:06:00.25 | +10:17:37.3 | HIP 59025 | 11.40 |
| 2026-10-01 00:00 | 12:06:11.14 | +10:15:57.8 | HIP 59025 | 13.03 |
| 2026-10-01 12:00 | 12:06:22.02 | +10:14:18.6 | HIP 59025 | 15.14 |
| 2026-10-02 00:00 | 12:06:32.89 | +10:12:39.7 | HIP 59025 | 17.56 |
| 2026-10-02 12:00 | 12:06:43.74 | +10:11:01.1 | HIP 59025 | 20.17 |
| 2026-10-03 00:00 | 12:06:54.58 | +10:09:22.8 | HIP 59025 | 22.90 |
| 2026-10-03 12:00 | 12:07:05.40 | +10:07:44.8 | HIP 59110 | 24.29 |
| 2026-10-04 00:00 | 12:07:16.22 | +10:06:07.2 | HIP 59110 | 25.77 |
| 2026-10-04 12:00 | 12:07:27.01 | +10:04:29.8 | HIP 59100 | 25.04 |
| 2026-10-05 00:00 | 12:07:37.79 | +10:02:52.8 | HIP 59100 | 24.04 |
| 2026-10-05 12:00 | 12:07:48.56 | +10:01:16.0 | HIP 59100 | 23.42 |
| 2026-10-06 00:00 | 12:07:59.31 | +09:59:39.6 | HIP 59100 | 23.20 |
| 2026-10-06 12:00 | 12:08:10.04 | +09:58:03.6 | HIP 59100 | 23.40 |
| 2026-10-07 00:00 | 12:08:20.75 | +09:56:27.8 | HIP 59100 | 23.99 |
| 2026-10-07 12:00 | 12:08:31.45 | +09:54:52.4 | HIP 59100 | 24.96 |
| 2026-10-08 00:00 | 12:08:42.13 | +09:53:17.3 | HIP 59100 | 26.25 |
| 2026-10-08 12:00 | 12:08:52.78 | +09:51:42.6 | HIP 59100 | 27.82 |
| 2026-10-09 00:00 | 12:09:03.42 | +09:50:08.2 | HIP 59100 | 29.62 |
| 2026-10-09 12:00 | 12:09:14.04 | +09:48:34.1 | HIP 59100 | 31.62 |
| 2026-10-10 00:00 | 12:09:24.64 | +09:47:00.4 | HIP 59286 | 29.84 |
| 2026-10-10 12:00 | 12:09:35.21 | +09:45:27.1 | HIP 59286 | 28.02 |
| 2026-10-11 00:00 | 12:09:45.76 | +09:43:54.1 | HIP 59286 | 26.44 |