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 · University of Arizona 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) |
|---|---|---|---|---|
| 2026-06-01 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 |
| 2026-06-02 12:00 | 17:28:09.70 | -30:29:59.4 | HIP 85531 | 27.02 |
| 2026-06-03 00:00 | 17:27:47.64 | -30:31:10.2 | HIP 85531 | 27.68 |
| 2026-06-03 12:00 | 17:27:25.56 | -30:32:20.3 | HIP 85531 | 29.16 |
| 2026-06-04 00:00 | 17:27:03.46 | -30:33:29.8 | HIP 85531 | 31.35 |
| 2026-06-04 12:00 | 17:26:41.33 | -30:34:38.7 | HIP 85281 | 28.68 |
| 2026-06-05 00:00 | 17:26:19.19 | -30:35:46.9 | HIP 85281 | 25.49 |
| 2026-06-05 12:00 | 17:25:57.02 | -30:36:54.4 | HIP 85281 | 22.92 |
| 2026-06-06 00:00 | 17:25:34.85 | -30:38:01.3 | HIP 85281 | 21.20 |
| 2026-06-06 12:00 | 17:25:12.66 | -30:39:07.5 | HIP 85281 | 20.54 |
| 2026-06-07 00:00 | 17:24:50.47 | -30:40:13.0 | HIP 85281 | 21.03 |
| 2026-06-07 12:00 | 17:24:28.27 | -30:41:17.9 | HIP 85281 | 22.61 |
| 2026-06-08 00:00 | 17:24:06.07 | -30:42:22.1 | HIP 85281 | 25.06 |
| 2026-06-08 12:00 | 17:23:43.86 | -30:43:25.6 | HIP 84982 | 24.36 |
| 2026-06-09 00:00 | 17:23:21.66 | -30:44:28.5 | HIP 84982 | 21.23 |
| 2026-06-09 12:00 | 17:22:59.46 | -30:45:30.7 | HIP 84982 | 18.85 |
| 2026-06-10 00:00 | 17:22:37.28 | -30:46:32.3 | HIP 84982 | 17.54 |
| 2026-06-10 12:00 | 17:22:15.10 | -30:47:33.2 | HIP 84982 | 17.52 |
| 2026-06-11 00:00 | 17:21:52.93 | -30:48:33.4 | HIP 84982 | 18.80 |
| 2026-06-11 12:00 | 17:21:30.78 | -30:49:32.9 | HIP 84982 | 21.14 |
| 2026-06-12 00:00 | 17:21:08.65 | -30:50:31.8 | HIP 84982 | 24.23 |
| 2026-06-12 12:00 | 17:20:46.54 | -30:51:30.0 | HIP 84806 | 27.60 |
| 2026-06-13 00:00 | 17:20:24.45 | -30:52:27.5 | HIP 84806 | 27.21 |
| 2026-06-13 12:00 | 17:20:02.39 | -30:53:24.4 | HIP 84806 | 27.66 |
| 2026-06-14 00:00 | 17:19:40.36 | -30:54:20.6 | HIP 84611 | 26.43 |
| 2026-06-14 12:00 | 17:19:18.36 | -30:55:16.1 | HIP 84611 | 22.34 |
| 2026-06-15 00:00 | 17:18:56.40 | -30:56:11.0 | HIP 84611 | 18.60 |
| 2026-06-15 12:00 | 17:18:34.47 | -30:57:05.3 | HIP 84611 | 15.46 |
| 2026-06-16 00:00 | 17:18:12.58 | -30:57:58.8 | HIP 84611 | 13.34 |
| 2026-06-16 12:00 | 17:17:50.74 | -30:58:51.7 | HIP 84611 | 12.74 |
| 2026-06-17 00:00 | 17:17:28.95 | -30:59:44.0 | HIP 84611 | 13.84 |
| 2026-06-17 12:00 | 17:17:07.20 | -31:00:35.6 | HIP 84611 | 16.31 |
| 2026-06-18 00:00 | 17:16:45.50 | -31:01:26.5 | HIP 84611 | 19.61 |
| 2026-06-18 12:00 | 17:16:23.86 | -31:02:16.8 | HIP 84611 | 23.39 |
| 2026-06-19 00:00 | 17:16:02.27 | -31:03:06.5 | HIP 84381 | 20.76 |
| 2026-06-19 12:00 | 17:15:40.75 | -31:03:55.5 | HIP 84381 | 17.61 |
| 2026-06-20 00:00 | 17:15:19.28 | -31:04:43.9 | HIP 84381 | 15.29 |
| 2026-06-20 12:00 | 17:14:57.88 | -31:05:31.7 | HIP 84318 | 11.26 |
| 2026-06-21 00:00 | 17:14:36.54 | -31:06:18.8 | HIP 84318 | 7.53 |
| 2026-06-21 12:00 | 17:14:15.28 | -31:07:05.3 | HIP 84318 | 5.43 |
| 2026-06-22 00:00 | 17:13:54.08 | -31:07:51.2 | HIP 84318 | 6.70 |