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 | 0.997 |
| gb | -0.748 |
| k | 0.836 |
| δ90 | 9.994 |
| 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 | +9.6293 | +1.324 |
| 2020-12-16 | 2021-01-12 | -35.9795 | -3.709 |
| 2021-01-12 | 2021-01-28 | +43.7393 | -0.997 |
| 2021-01-28 | 2021-03-31 | -1.4294 | -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) |
|---|---|---|---|---|
| 2026-02-03 00:00 | 20:32:31.47 | -11:16:20.7 | HIP 101277 | 38.59 |
| 2026-02-03 12:00 | 20:34:02.87 | -11:10:00.8 | HIP 101590 | 21.56 |
| 2026-02-04 00:00 | 20:35:34.61 | -11:03:37.0 | HIP 101590 | 17.47 |
| 2026-02-04 12:00 | 20:37:06.67 | -10:57:09.2 | HIP 101811 | 13.00 |
| 2026-02-05 00:00 | 20:38:39.07 | -10:50:37.3 | HIP 101811 | 15.54 |
| 2026-02-05 12:00 | 20:40:11.81 | -10:44:01.4 | HIP 101956 | 12.91 |
| 2026-02-06 00:00 | 20:41:44.89 | -10:37:21.4 | HIP 102130 | 19.37 |
| 2026-02-06 12:00 | 20:43:18.31 | -10:30:37.4 | HIP 102266 | 13.91 |
| 2026-02-07 00:00 | 20:44:52.08 | -10:23:49.3 | HIP 102379 | 6.92 |
| 2026-02-07 12:00 | 20:46:26.19 | -10:16:57.1 | HIP 102455 | 14.72 |
| 2026-02-08 00:00 | 20:48:00.65 | -10:10:00.8 | HIP 102607 | 9.20 |
| 2026-02-08 12:00 | 20:49:35.46 | -10:03:00.3 | HIP 102652 | 28.08 |
| 2026-02-09 00:00 | 20:51:10.63 | -09:55:55.7 | HIP 103054 | 24.51 |
| 2026-02-09 12:00 | 20:52:46.15 | -09:48:47.0 | HIP 103054 | 15.13 |
| 2026-02-10 00:00 | 20:54:22.02 | -09:41:34.1 | HIP 103054 | 32.75 |
| 2026-02-10 12:00 | 20:55:58.26 | -09:34:17.0 | HIP 103379 | 11.43 |
| 2026-02-11 00:00 | 20:57:34.85 | -09:26:55.7 | HIP 103401 | 18.00 |
| 2026-02-11 12:00 | 20:59:11.82 | -09:19:30.2 | HIP 103599 | 10.84 |
| 2026-02-12 00:00 | 21:00:49.14 | -09:12:00.5 | HIP 103599 | 27.13 |
| 2026-02-12 12:00 | 21:02:26.84 | -09:04:26.5 | HIP 103840 | 22.43 |
| 2026-02-13 00:00 | 21:04:04.90 | -08:56:48.4 | HIP 104046 | 14.10 |
| 2026-02-13 12:00 | 21:05:43.34 | -08:49:06.0 | HIP 104046 | 14.60 |
| 2026-02-14 00:00 | 21:07:22.15 | -08:41:19.3 | HIP 104300 | 16.62 |
| 2026-02-14 12:00 | 21:09:01.34 | -08:33:28.4 | HIP 104300 | 20.03 |
| 2026-02-15 00:00 | 21:10:40.91 | -08:25:33.2 | HIP 104684 | 24.26 |
| 2026-02-15 12:00 | 21:12:20.86 | -08:17:33.8 | HIP 104684 | 3.94 |
| 2026-02-16 00:00 | 21:14:01.19 | -08:09:30.1 | HIP 104904 | 18.30 |
| 2026-02-16 12:00 | 21:15:41.92 | -08:01:22.1 | HIP 104898 | 21.61 |
| 2026-02-17 00:00 | 21:17:23.02 | -07:53:09.8 | HIP 105051 | 17.01 |
| 2026-02-17 12:00 | 21:19:04.52 | -07:44:53.2 | HIP 105243 | 7.83 |
| 2026-02-18 00:00 | 21:20:46.42 | -07:36:32.4 | HIP 105486 | 18.01 |
| 2026-02-18 12:00 | 21:22:28.71 | -07:28:07.3 | HIP 105486 | 8.71 |
| 2026-02-19 00:00 | 21:24:11.39 | -07:19:37.9 | HIP 105667 | 35.00 |
| 2026-02-19 12:00 | 21:25:54.48 | -07:11:04.2 | HIP 105947 | 24.24 |
| 2026-02-20 00:00 | 21:27:37.97 | -07:02:26.2 | HIP 105947 | 3.95 |
| 2026-02-20 12:00 | 21:29:21.86 | -06:53:44.0 | HIP 106146 | 25.83 |
| 2026-02-21 00:00 | 21:31:06.16 | -06:44:57.5 | HIP 106299 | 16.23 |
| 2026-02-21 12:00 | 21:32:50.87 | -06:36:06.8 | HIP 106455 | 18.24 |
| 2026-02-22 00:00 | 21:34:35.99 | -06:27:11.8 | HIP 106455 | 14.84 |
| 2026-02-22 12:00 | 21:36:21.53 | -06:18:12.5 | HIP 106702 | 19.06 |
| 2026-02-23 00:00 | 21:38:07.49 | -06:09:09.0 | HIP 106702 | 21.73 |
| 2026-02-23 12:00 | 21:39:53.86 | -06:00:01.3 | HIP 107007 | 23.06 |
| 2026-02-24 00:00 | 21:41:40.66 | -05:50:49.3 | HIP 107158 | 15.95 |