405P/Lemmon
Metadata
| Parameter | Value |
|---|---|
| Designation | 405P/Lemmon |
| Type | P |
| Perihelion (tp_cal, UTC) | 2020-12-24T14:12:20.220480Z |
| Orbit solution date (soln_date, UTC) | 2021-05-31T22:43:11Z |
| Obs used | 1017 |
| NEO | Yes |
| M1 | 18.800 |
| K1 | 4.500 |
| PC | - |
| Discovery observation (MPC, UTC) | 2020-10-17T03:08:48.076800Z |
| Discovery magnitude (MPC) | 18.80 G |
| Discovery observatory (MPC) | Z84 · Calar Alto-Schmidt |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2017-12-04.0000000 |
| e | 0.68914700 |
| q (au) | 1.121217 |
| a (au) | 3.606904 |
| i (deg) | 9.365069 |
| Ω (om, deg) | 3.311168 |
| ω (w, deg) | 112.292821 |
| M (ma, deg) | 199.344113 |
Magnitude
Scatter + Global Linear
$$ M_a = (19.090 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 19.090 |
| n | 2.000 |
| gf | 0.800 |
| gb | -0.500 |
| k | 0.800 |
| δ90 | 2.314 |
| 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 |
|---|---|---|---|
| 2020-06-28 | 2020-12-24 | -1.5360 | -0.178 |
| 2020-12-24 | 2021-03-05 | +6.7770 | -0.321 |
| 2021-03-05 | 2021-05-10 | -7.1641 | +1.615 |
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) |
|---|---|---|---|---|
| 2026-05-12 00:00 | 22:51:52.03 | -12:57:16.1 | HIP 112980 | 16.43 |
| 2026-05-12 12:00 | 22:52:07.95 | -12:55:55.6 | HIP 112980 | 14.21 |
| 2026-05-13 00:00 | 22:52:23.76 | -12:54:36.0 | HIP 112980 | 12.96 |
| 2026-05-13 12:00 | 22:52:39.43 | -12:53:17.1 | HIP 112980 | 12.91 |
| 2026-05-14 00:00 | 22:52:54.99 | -12:51:59.1 | HIP 112980 | 14.06 |
| 2026-05-14 12:00 | 22:53:10.42 | -12:50:42.0 | HIP 112980 | 16.13 |
| 2026-05-15 00:00 | 22:53:25.72 | -12:49:25.7 | HIP 112980 | 18.79 |
| 2026-05-15 12:00 | 22:53:40.90 | -12:48:10.3 | HIP 112980 | 21.81 |
| 2026-05-16 00:00 | 22:53:55.95 | -12:46:55.7 | HIP 112980 | 25.05 |
| 2026-05-16 12:00 | 22:54:10.86 | -12:45:42.0 | HIP 112980 | 28.41 |
| 2026-05-17 00:00 | 22:54:25.65 | -12:44:29.2 | HIP 113250 | 26.23 |
| 2026-05-17 12:00 | 22:54:40.31 | -12:43:17.3 | HIP 113250 | 23.92 |
| 2026-05-18 00:00 | 22:54:54.83 | -12:42:06.2 | HIP 113250 | 22.04 |
| 2026-05-18 12:00 | 22:55:09.22 | -12:40:56.1 | HIP 113250 | 20.67 |
| 2026-05-19 00:00 | 22:55:23.47 | -12:39:46.8 | HIP 113264 | 19.26 |
| 2026-05-19 12:00 | 22:55:37.59 | -12:38:38.5 | HIP 113264 | 16.47 |
| 2026-05-20 00:00 | 22:55:51.57 | -12:37:31.1 | HIP 113264 | 14.08 |
| 2026-05-20 12:00 | 22:56:05.41 | -12:36:24.6 | HIP 113264 | 12.32 |
| 2026-05-21 00:00 | 22:56:19.12 | -12:35:19.1 | HIP 113264 | 11.42 |
| 2026-05-21 12:00 | 22:56:32.68 | -12:34:14.4 | HIP 113264 | 11.58 |
| 2026-05-22 00:00 | 22:56:46.11 | -12:33:10.8 | HIP 113264 | 12.71 |
| 2026-05-22 12:00 | 22:56:59.39 | -12:32:08.0 | HIP 113264 | 14.56 |
| 2026-05-23 00:00 | 22:57:12.53 | -12:31:06.2 | HIP 113264 | 16.88 |
| 2026-05-23 12:00 | 22:57:25.53 | -12:30:05.4 | HIP 113264 | 19.48 |
| 2026-05-24 00:00 | 22:57:38.38 | -12:29:05.5 | HIP 113264 | 22.25 |
| 2026-05-24 12:00 | 22:57:51.09 | -12:28:06.6 | HIP 113264 | 25.11 |
| 2026-05-25 00:00 | 22:58:03.65 | -12:27:08.7 | HIP 113264 | 28.02 |
| 2026-05-25 12:00 | 22:58:16.07 | -12:26:11.7 | HIP 113529 | 27.19 |
| 2026-05-26 00:00 | 22:58:28.33 | -12:25:15.7 | HIP 113529 | 25.91 |
| 2026-05-26 12:00 | 22:58:40.45 | -12:24:20.7 | HIP 113529 | 24.97 |
| 2026-05-27 00:00 | 22:58:52.42 | -12:23:26.7 | HIP 113529 | 24.39 |
| 2026-05-27 12:00 | 22:59:04.23 | -12:22:33.7 | HIP 113529 | 24.18 |
| 2026-05-28 00:00 | 22:59:15.90 | -12:21:41.8 | HIP 113529 | 24.34 |
| 2026-05-28 12:00 | 22:59:27.41 | -12:20:50.8 | HIP 113529 | 24.83 |
| 2026-05-29 00:00 | 22:59:38.77 | -12:20:00.8 | HIP 113529 | 25.64 |
| 2026-05-29 12:00 | 22:59:49.97 | -12:19:11.9 | HIP 113529 | 26.71 |
| 2026-05-30 00:00 | 23:00:01.02 | -12:18:24.0 | HIP 113529 | 28.01 |
| 2026-05-30 12:00 | 23:00:11.90 | -12:17:37.1 | HIP 113529 | 29.50 |
| 2026-05-31 00:00 | 23:00:22.64 | -12:16:51.3 | HIP 113771 | 30.53 |
| 2026-05-31 12:00 | 23:00:33.21 | -12:16:06.5 | HIP 113771 | 28.20 |
| 2026-06-01 00:00 | 23:00:43.62 | -12:15:22.8 | HIP 113771 | 25.98 |
| 2026-06-01 12:00 | 23:00:53.87 | -12:14:40.1 | HIP 113771 | 23.87 |
| 2026-06-02 00:00 | 23:01:03.96 | -12:13:58.5 | HIP 113771 | 21.89 |