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) |
|---|---|---|---|---|
| 2026-05-12 00:00 | 17:42:56.94 | -29:29:57.8 | HIP 86665 | 7.45 |
| 2026-05-12 12:00 | 17:42:38.41 | -29:31:32.3 | HIP 86665 | 5.76 |
| 2026-05-13 00:00 | 17:42:19.74 | -29:33:06.4 | HIP 86665 | 6.96 |
| 2026-05-13 12:00 | 17:42:00.95 | -29:34:40.0 | HIP 86665 | 10.09 |
| 2026-05-14 00:00 | 17:41:42.02 | -29:36:13.2 | HIP 86522 | 10.68 |
| 2026-05-14 12:00 | 17:41:22.97 | -29:37:46.0 | HIP 86522 | 6.78 |
| 2026-05-15 00:00 | 17:41:03.80 | -29:39:18.3 | HIP 86522 | 4.08 |
| 2026-05-15 12:00 | 17:40:44.51 | -29:40:50.1 | HIP 86522 | 5.18 |
| 2026-05-16 00:00 | 17:40:25.09 | -29:42:21.5 | HIP 86522 | 8.78 |
| 2026-05-16 12:00 | 17:40:05.57 | -29:43:52.4 | HIP 86522 | 12.96 |
| 2026-05-17 00:00 | 17:39:45.92 | -29:45:22.9 | HIP 86404 | 14.61 |
| 2026-05-17 12:00 | 17:39:26.17 | -29:46:52.8 | HIP 86404 | 15.08 |
| 2026-05-18 00:00 | 17:39:06.30 | -29:48:22.3 | HIP 86404 | 16.80 |
| 2026-05-18 12:00 | 17:38:46.33 | -29:49:51.2 | HIP 86260 | 16.36 |
| 2026-05-19 00:00 | 17:38:26.25 | -29:51:19.7 | HIP 86260 | 12.83 |
| 2026-05-19 12:00 | 17:38:06.07 | -29:52:47.6 | HIP 86260 | 10.18 |
| 2026-05-20 00:00 | 17:37:45.79 | -29:54:15.1 | HIP 86260 | 9.21 |
| 2026-05-20 12:00 | 17:37:25.42 | -29:55:42.0 | HIP 86260 | 10.44 |
| 2026-05-21 00:00 | 17:37:04.95 | -29:57:08.3 | HIP 86260 | 13.28 |
| 2026-05-21 12:00 | 17:36:44.38 | -29:58:34.2 | HIP 86260 | 16.95 |
| 2026-05-22 00:00 | 17:36:23.73 | -29:59:59.5 | HIP 86138 | 19.42 |
| 2026-05-22 12:00 | 17:36:02.99 | -30:01:24.2 | HIP 86138 | 20.73 |
| 2026-05-23 00:00 | 17:35:42.16 | -30:02:48.4 | HIP 86138 | 22.95 |
| 2026-05-23 12:00 | 17:35:21.26 | -30:04:12.0 | HIP 86138 | 25.85 |
| 2026-05-24 00:00 | 17:35:00.27 | -30:05:35.1 | HIP 86138 | 29.24 |
| 2026-05-24 12:00 | 17:34:39.20 | -30:06:57.6 | HIP 86140 | 32.57 |
| 2026-05-25 00:00 | 17:34:18.07 | -30:08:19.5 | HIP 85881 | 33.45 |
| 2026-05-25 12:00 | 17:33:56.85 | -30:09:40.8 | HIP 85803 | 29.69 |
| 2026-05-26 00:00 | 17:33:35.57 | -30:11:01.6 | HIP 85803 | 25.04 |
| 2026-05-26 12:00 | 17:33:14.22 | -30:12:21.7 | HIP 85803 | 20.45 |
| 2026-05-27 00:00 | 17:32:52.81 | -30:13:41.3 | HIP 85803 | 15.98 |
| 2026-05-27 12:00 | 17:32:31.33 | -30:15:00.2 | HIP 85803 | 11.77 |
| 2026-05-28 00:00 | 17:32:09.80 | -30:16:18.6 | HIP 85775 | 7.45 |
| 2026-05-28 12:00 | 17:31:48.21 | -30:17:36.3 | HIP 85775 | 2.68 |
| 2026-05-29 00:00 | 17:31:26.56 | -30:18:53.5 | HIP 85739 | 2.11 |
| 2026-05-29 12:00 | 17:31:04.86 | -30:20:10.0 | HIP 85739 | 2.76 |
| 2026-05-30 00:00 | 17:30:43.11 | -30:21:25.9 | HIP 85739 | 7.61 |
| 2026-05-30 12:00 | 17:30:21.32 | -30:22:41.1 | HIP 85739 | 12.48 |
| 2026-05-31 00:00 | 17:29:59.48 | -30:23:55.8 | HIP 85739 | 17.35 |
| 2026-05-31 12:00 | 17:29:37.59 | -30:25:09.8 | HIP 85739 | 22.22 |
| 2026-06-01 00:00 | 17:29:15.67 | -30:26:23.1 | HIP 85739 | 27.10 |
| 2026-06-01 12:00 | 17:28:53.71 | -30:27:35.9 | HIP 85531 | 28.35 |
| 2026-06-02 00:00 | 17:28:31.72 | -30:28:48.0 | HIP 85531 | 27.26 |