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) |
|---|---|---|---|---|
| 2026-02-03 00:00 | 17:46:07.97 | -24:03:11.5 | HIP 86970 | 6.60 |
| 2026-02-03 12:00 | 17:46:23.13 | -24:04:46.1 | HIP 86970 | 3.73 |
| 2026-02-04 00:00 | 17:46:38.17 | -24:06:20.6 | HIP 86970 | 3.61 |
| 2026-02-04 12:00 | 17:46:53.09 | -24:07:55.1 | HIP 86970 | 6.35 |
| 2026-02-05 00:00 | 17:47:07.89 | -24:09:29.5 | HIP 86970 | 9.76 |
| 2026-02-05 12:00 | 17:47:22.57 | -24:11:03.9 | HIP 86970 | 13.31 |
| 2026-02-06 00:00 | 17:47:37.13 | -24:12:38.3 | HIP 86970 | 16.89 |
| 2026-02-06 12:00 | 17:47:51.57 | -24:14:12.6 | HIP 86970 | 20.48 |
| 2026-02-07 00:00 | 17:48:05.88 | -24:15:46.9 | HIP 86970 | 24.06 |
| 2026-02-07 12:00 | 17:48:20.06 | -24:17:21.1 | HIP 87273 | 22.75 |
| 2026-02-08 00:00 | 17:48:34.12 | -24:18:55.4 | HIP 87273 | 20.08 |
| 2026-02-08 12:00 | 17:48:48.06 | -24:20:29.6 | HIP 87273 | 17.76 |
| 2026-02-09 00:00 | 17:49:01.86 | -24:22:03.7 | HIP 87273 | 15.93 |
| 2026-02-09 12:00 | 17:49:15.54 | -24:23:37.9 | HIP 87273 | 14.73 |
| 2026-02-10 00:00 | 17:49:29.09 | -24:25:12.1 | HIP 87273 | 14.33 |
| 2026-02-10 12:00 | 17:49:42.50 | -24:26:46.2 | HIP 87273 | 14.75 |
| 2026-02-11 00:00 | 17:49:55.79 | -24:28:20.4 | HIP 87273 | 15.93 |
| 2026-02-11 12:00 | 17:50:08.94 | -24:29:54.5 | HIP 87273 | 17.68 |
| 2026-02-12 00:00 | 17:50:21.96 | -24:31:28.6 | HIP 87273 | 19.86 |
| 2026-02-12 12:00 | 17:50:34.85 | -24:33:02.8 | HIP 87273 | 22.31 |
| 2026-02-13 00:00 | 17:50:47.60 | -24:34:36.9 | HIP 87453 | 19.30 |
| 2026-02-13 12:00 | 17:51:00.21 | -24:36:11.1 | HIP 87453 | 16.12 |
| 2026-02-14 00:00 | 17:51:12.68 | -24:37:45.3 | HIP 87453 | 13.03 |
| 2026-02-14 12:00 | 17:51:25.02 | -24:39:19.5 | HIP 87453 | 10.05 |
| 2026-02-15 00:00 | 17:51:37.21 | -24:40:53.7 | HIP 87453 | 7.31 |
| 2026-02-15 12:00 | 17:51:49.27 | -24:42:28.0 | HIP 87453 | 5.14 |
| 2026-02-16 00:00 | 17:52:01.18 | -24:44:02.3 | HIP 87453 | 4.41 |
| 2026-02-16 12:00 | 17:52:12.95 | -24:45:36.6 | HIP 87453 | 5.66 |
| 2026-02-17 00:00 | 17:52:24.58 | -24:47:10.9 | HIP 87453 | 7.98 |
| 2026-02-17 12:00 | 17:52:36.07 | -24:48:45.3 | HIP 87453 | 10.67 |
| 2026-02-18 00:00 | 17:52:47.40 | -24:50:19.8 | HIP 87453 | 13.49 |
| 2026-02-18 12:00 | 17:52:58.59 | -24:51:54.2 | HIP 87453 | 16.35 |
| 2026-02-19 00:00 | 17:53:09.64 | -24:53:28.8 | HIP 87453 | 19.23 |
| 2026-02-19 12:00 | 17:53:20.53 | -24:55:03.4 | HIP 87706 | 21.28 |
| 2026-02-20 00:00 | 17:53:31.28 | -24:56:38.0 | HIP 87706 | 19.07 |
| 2026-02-20 12:00 | 17:53:41.88 | -24:58:12.7 | HIP 87706 | 17.10 |
| 2026-02-21 00:00 | 17:53:52.32 | -24:59:47.5 | HIP 87706 | 15.46 |
| 2026-02-21 12:00 | 17:54:02.61 | -25:01:22.3 | HIP 87706 | 14.22 |
| 2026-02-22 00:00 | 17:54:12.75 | -25:02:57.2 | HIP 87706 | 13.50 |
| 2026-02-22 12:00 | 17:54:22.74 | -25:04:32.2 | HIP 87706 | 13.35 |
| 2026-02-23 00:00 | 17:54:32.57 | -25:06:07.2 | HIP 87706 | 13.78 |
| 2026-02-23 12:00 | 17:54:42.25 | -25:07:42.4 | HIP 87706 | 14.73 |
| 2026-02-24 00:00 | 17:54:51.77 | -25:09:17.6 | HIP 87706 | 16.08 |