C/2024 B1 (Lemmon)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2024 B1 (Lemmon) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2024-10-07T16:58:54.436800Z |
| Orbit solution date (soln_date, UTC) | 2025-09-09T12:42:32Z |
| Obs used | 763 |
| NEO | - |
| M1 | 12.600 |
| K1 | 6.500 |
| PC | 0.030 |
| Discovery observation (MPC, UTC) | 2024-01-16T04:11:52.224000Z |
| Discovery magnitude (MPC) | 20.65 G |
| Discovery observatory (MPC) | G96 · Mt. Lemmon Survey |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2025-02-28.0000000 |
| e | 1.00088003 |
| q (au) | 1.633728 |
| a (au) | -1856.447475 |
| i (deg) | 70.903802 |
| Ω (om, deg) | 79.187466 |
| ω (w, deg) | 66.211826 |
| M (ma, deg) | 0.001766 |
Magnitude
Scatter + Global Linear
$$ M_a = (12.317 + 3.691\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 12.317 |
| n | 3.691 |
| gf | 1.000 |
| gb | -0.572 |
| 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 |
|---|---|---|---|
| 2023-10-13 | 2024-10-05 | +5.5116 | -1.105 |
| 2024-10-09 | 2025-01-21 | +0.2899 | -0.213 |
| 2025-01-21 | 2025-06-03 | +1.7670 | -0.947 |
| 2025-06-03 | 2025-08-19 | -1.4005 | +0.591 |
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) |
|---|---|---|---|---|
| 2026-03-26 00:00 | 17:59:09.66 | -26:48:09.8 | HIP 88029 | 4.63 |
| 2026-03-26 12:00 | 17:59:08.29 | -26:49:52.9 | HIP 88029 | 4.07 |
| 2026-03-27 00:00 | 17:59:06.72 | -26:51:36.1 | HIP 88029 | 4.18 |
| 2026-03-27 12:00 | 17:59:04.96 | -26:53:19.4 | HIP 88029 | 4.92 |
| 2026-03-28 00:00 | 17:59:03.00 | -26:55:02.9 | HIP 88029 | 6.08 |
| 2026-03-28 12:00 | 17:59:00.84 | -26:56:46.5 | HIP 88029 | 7.48 |
| 2026-03-29 00:00 | 17:58:58.49 | -26:58:30.2 | HIP 88029 | 9.01 |
| 2026-03-29 12:00 | 17:58:55.94 | -27:00:14.0 | HIP 88100 | 9.88 |
| 2026-03-30 00:00 | 17:58:53.19 | -27:01:58.0 | HIP 88100 | 9.92 |
| 2026-03-30 12:00 | 17:58:50.24 | -27:03:42.1 | HIP 88100 | 10.34 |
| 2026-03-31 00:00 | 17:58:47.10 | -27:05:26.2 | HIP 88100 | 11.10 |
| 2026-03-31 12:00 | 17:58:43.76 | -27:07:10.5 | HIP 88100 | 12.14 |
| 2026-04-01 00:00 | 17:58:40.22 | -27:08:54.9 | HIP 88100 | 13.42 |
| 2026-04-01 12:00 | 17:58:36.48 | -27:10:39.4 | HIP 88100 | 14.87 |
| 2026-04-02 00:00 | 17:58:32.54 | -27:12:24.0 | HIP 88100 | 16.46 |
| 2026-04-02 12:00 | 17:58:28.41 | -27:14:08.7 | HIP 88100 | 18.16 |
| 2026-04-03 00:00 | 17:58:24.07 | -27:15:53.5 | HIP 88026 | 17.58 |
| 2026-04-03 12:00 | 17:58:19.54 | -27:17:38.3 | HIP 88026 | 16.27 |
| 2026-04-04 00:00 | 17:58:14.80 | -27:19:23.3 | HIP 88026 | 15.14 |
| 2026-04-04 12:00 | 17:58:09.87 | -27:21:08.4 | HIP 88026 | 14.24 |
| 2026-04-05 00:00 | 17:58:04.74 | -27:22:53.5 | HIP 88026 | 13.62 |
| 2026-04-05 12:00 | 17:57:59.41 | -27:24:38.7 | HIP 88026 | 13.34 |
| 2026-04-06 00:00 | 17:57:53.87 | -27:26:24.0 | HIP 88026 | 13.42 |
| 2026-04-06 12:00 | 17:57:48.14 | -27:28:09.3 | HIP 88026 | 13.89 |
| 2026-04-07 00:00 | 17:57:42.21 | -27:29:54.7 | HIP 88026 | 14.70 |
| 2026-04-07 12:00 | 17:57:36.08 | -27:31:40.2 | HIP 88026 | 15.83 |
| 2026-04-08 00:00 | 17:57:29.75 | -27:33:25.7 | HIP 88026 | 17.21 |
| 2026-04-08 12:00 | 17:57:23.22 | -27:35:11.3 | HIP 88026 | 18.81 |
| 2026-04-09 00:00 | 17:57:16.49 | -27:36:56.9 | HIP 88026 | 20.57 |
| 2026-04-09 12:00 | 17:57:09.55 | -27:38:42.6 | HIP 88026 | 22.48 |
| 2026-04-10 00:00 | 17:57:02.42 | -27:40:28.3 | HIP 87836 | 23.89 |
| 2026-04-10 12:00 | 17:56:55.09 | -27:42:14.1 | HIP 87836 | 21.88 |
| 2026-04-11 00:00 | 17:56:47.56 | -27:43:59.9 | HIP 87836 | 19.96 |
| 2026-04-11 12:00 | 17:56:39.83 | -27:45:45.7 | HIP 87836 | 18.16 |
| 2026-04-12 00:00 | 17:56:31.90 | -27:47:31.5 | HIP 87836 | 16.54 |
| 2026-04-12 12:00 | 17:56:23.77 | -27:49:17.3 | HIP 87836 | 15.16 |
| 2026-04-13 00:00 | 17:56:15.45 | -27:51:03.2 | HIP 87836 | 14.12 |
| 2026-04-13 12:00 | 17:56:06.92 | -27:52:49.1 | HIP 87836 | 13.52 |
| 2026-04-14 00:00 | 17:55:58.20 | -27:54:34.9 | HIP 87836 | 13.42 |
| 2026-04-14 12:00 | 17:55:49.27 | -27:56:20.8 | HIP 87836 | 13.85 |
| 2026-04-15 00:00 | 17:55:40.15 | -27:58:06.6 | HIP 87836 | 14.80 |
| 2026-04-15 12:00 | 17:55:30.83 | -27:59:52.4 | HIP 87684 | 14.95 |
| 2026-04-16 00:00 | 17:55:21.32 | -28:01:38.2 | HIP 87684 | 12.23 |