141P/Machholz 2
Metadata
| Parameter | Value |
|---|---|
| Designation | 141P/Machholz 2 |
| Type | P |
| Perihelion (tp_cal, UTC) | 2020-12-15T22:59:55.132800Z |
| Orbit solution date (soln_date, UTC) | 2024-08-26T12:39:49Z |
| Obs used | 852 |
| NEO | Yes |
| M1 | 17.300 |
| K1 | 4.500 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2019-08-01.0000000 |
| e | 0.73668750 |
| q (au) | 0.804381 |
| a (au) | 3.054854 |
| i (deg) | 13.977322 |
| Ω (om, deg) | 241.877240 |
| ω (w, deg) | 153.615394 |
| M (ma, deg) | 267.156738 |
Magnitude
Scatter + Global Linear
$$ M_a = (16.744 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 16.744 |
| n | 2.000 |
| gf | 0.998 |
| gb | -0.747 |
| k | 0.836 |
| δ90 | 9.995 |
| 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 |
|---|---|---|---|
| 2020-08-13 | 2020-12-15 | +9.6272 | +1.324 |
| 2020-12-16 | 2021-01-12 | -35.9796 | -3.709 |
| 2021-01-12 | 2021-01-28 | +43.7428 | -0.997 |
| 2021-01-28 | 2021-03-31 | -1.4306 | -0.971 |
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) |
|---|---|---|---|---|
| 2026-07-29 00:00 | 08:47:28.29 | +09:16:36.8 | HIP 43134 | 7.81 |
| 2026-07-29 12:00 | 08:48:44.05 | +09:10:16.0 | HIP 43317 | 21.49 |
| 2026-07-30 00:00 | 08:49:59.46 | +09:03:55.1 | HIP 43317 | 14.18 |
| 2026-07-30 12:00 | 08:51:14.52 | +08:57:34.1 | HIP 43582 | 20.68 |
| 2026-07-31 00:00 | 08:52:29.24 | +08:51:13.1 | HIP 43582 | 12.88 |
| 2026-07-31 12:00 | 08:53:43.61 | +08:44:52.1 | HIP 43692 | 19.89 |
| 2026-08-01 00:00 | 08:54:57.65 | +08:38:31.0 | HIP 43692 | 19.84 |
| 2026-08-01 12:00 | 08:56:11.36 | +08:32:10.0 | HIP 43692 | 33.73 |
| 2026-08-02 00:00 | 08:57:24.73 | +08:25:49.0 | HIP 44079 | 23.51 |
| 2026-08-02 12:00 | 08:58:37.77 | +08:19:27.9 | HIP 44079 | 6.33 |
| 2026-08-03 00:00 | 08:59:50.48 | +08:13:06.9 | HIP 44079 | 16.09 |
| 2026-08-03 12:00 | 09:01:02.87 | +08:06:46.0 | HIP 44376 | 28.57 |
| 2026-08-04 00:00 | 09:02:14.94 | +08:00:25.1 | HIP 44376 | 27.74 |
| 2026-08-04 12:00 | 09:03:26.69 | +07:54:04.2 | HIP 44398 | 37.05 |
| 2026-08-05 00:00 | 09:04:38.13 | +07:47:43.4 | HIP 44406 | 40.97 |
| 2026-08-05 12:00 | 09:05:49.25 | +07:41:22.7 | HIP 44780 | 29.50 |
| 2026-08-06 00:00 | 09:07:00.06 | +07:35:02.0 | HIP 44780 | 11.02 |
| 2026-08-06 12:00 | 09:08:10.56 | +07:28:41.5 | HIP 44869 | 6.18 |
| 2026-08-07 00:00 | 09:09:20.76 | +07:22:21.0 | HIP 44916 | 9.65 |
| 2026-08-07 12:00 | 09:10:30.65 | +07:16:00.7 | HIP 45010 | 16.78 |
| 2026-08-08 00:00 | 09:11:40.24 | +07:09:40.5 | HIP 45194 | 18.99 |
| 2026-08-08 12:00 | 09:12:49.53 | +07:03:20.4 | HIP 45194 | 7.71 |
| 2026-08-09 00:00 | 09:13:58.52 | +06:57:00.4 | HIP 45194 | 20.66 |
| 2026-08-09 12:00 | 09:15:07.22 | +06:50:40.6 | HIP 45471 | 21.93 |
| 2026-08-10 00:00 | 09:16:15.63 | +06:44:20.9 | HIP 45471 | 12.83 |
| 2026-08-10 12:00 | 09:17:23.75 | +06:38:01.4 | HIP 45471 | 22.41 |
| 2026-08-11 00:00 | 09:18:31.57 | +06:31:42.0 | HIP 45653 | 32.79 |
| 2026-08-11 12:00 | 09:19:39.11 | +06:25:22.9 | HIP 45901 | 36.94 |
| 2026-08-12 00:00 | 09:20:46.37 | +06:19:03.9 | HIP 45950 | 22.75 |
| 2026-08-12 12:00 | 09:21:53.34 | +06:12:45.1 | HIP 45950 | 7.93 |
| 2026-08-13 00:00 | 09:23:00.04 | +06:06:26.6 | HIP 45950 | 15.51 |
| 2026-08-13 12:00 | 09:24:06.45 | +06:00:08.2 | HIP 46111 | 21.07 |
| 2026-08-14 00:00 | 09:25:12.58 | +05:53:50.1 | HIP 46111 | 20.63 |
| 2026-08-14 12:00 | 09:26:18.44 | +05:47:32.1 | HIP 46196 | 25.99 |
| 2026-08-15 00:00 | 09:27:24.03 | +05:41:14.5 | HIP 46437 | 18.11 |
| 2026-08-15 12:00 | 09:28:29.35 | +05:34:57.1 | HIP 46437 | 19.70 |
| 2026-08-16 00:00 | 09:29:34.39 | +05:28:39.9 | HIP 46580 | 11.81 |
| 2026-08-16 12:00 | 09:30:39.17 | +05:22:23.0 | HIP 46580 | 20.15 |
| 2026-08-17 00:00 | 09:31:43.68 | +05:16:06.4 | HIP 46846 | 17.46 |
| 2026-08-17 12:00 | 09:32:47.93 | +05:09:50.0 | HIP 46846 | 2.61 |
| 2026-08-18 00:00 | 09:33:51.91 | +05:03:33.9 | HIP 46846 | 17.24 |
| 2026-08-18 12:00 | 09:34:55.64 | +04:57:18.1 | HIP 47008 | 17.59 |
| 2026-08-19 00:00 | 09:35:59.10 | +04:51:02.7 | HIP 47157 | 14.97 |