C/2000 WM1 (LINEAR)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2000 WM1 (LINEAR) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2002-01-22T16:09:23.857920Z |
| Orbit solution date (soln_date, UTC) | 2021-04-15T23:30:08Z |
| Obs used | 2130 |
| NEO | - |
| M1 | 11.200 |
| K1 | 4.750 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2002-01-24.0000000 |
| e | 1.00024278 |
| q (au) | 0.555348 |
| a (au) | -2287.433616 |
| i (deg) | 72.550229 |
| Ω (om, deg) | 237.895729 |
| ω (w, deg) | 276.770906 |
| M (ma, deg) | 0.000012 |
Magnitude
Scatter + Global Linear
$$ M_a = (7.292 + 4.602\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 7.292 |
| n | 4.602 |
| gf | 0.800 |
| gb | -0.500 |
| k | 0.800 |
| δ90 | 1.000 |
| 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 |
|---|---|---|---|
| 2000-12-22 | 2002-01-22 | -2.0781 | +0.678 |
| 2002-01-22 | 2002-02-04 | -39.9944 | -10.010 |
| 2002-02-04 | 2002-05-18 | +3.0549 | -0.945 |
| 2002-05-18 | 2003-06-05 | +0.1428 | +0.246 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-07-29 00:00 | 19:11:11.96 | +51:50:03.5 | HIP 94266 | 11.42 |
| 2026-07-29 12:00 | 19:11:08.26 | +51:49:50.6 | HIP 94266 | 11.66 |
| 2026-07-30 00:00 | 19:11:04.58 | +51:49:37.3 | HIP 94266 | 11.93 |
| 2026-07-30 12:00 | 19:11:00.90 | +51:49:23.8 | HIP 94266 | 12.23 |
| 2026-07-31 00:00 | 19:10:57.24 | +51:49:10.0 | HIP 94266 | 12.56 |
| 2026-07-31 12:00 | 19:10:53.59 | +51:48:56.0 | HIP 94266 | 12.91 |
| 2026-08-01 00:00 | 19:10:49.95 | +51:48:41.6 | HIP 94266 | 13.29 |
| 2026-08-01 12:00 | 19:10:46.33 | +51:48:26.9 | HIP 94266 | 13.69 |
| 2026-08-02 00:00 | 19:10:42.72 | +51:48:12.0 | HIP 94266 | 14.10 |
| 2026-08-02 12:00 | 19:10:39.13 | +51:47:56.8 | HIP 94266 | 14.53 |
| 2026-08-03 00:00 | 19:10:35.55 | +51:47:41.3 | HIP 94266 | 14.98 |
| 2026-08-03 12:00 | 19:10:31.98 | +51:47:25.5 | HIP 94266 | 15.45 |
| 2026-08-04 00:00 | 19:10:28.43 | +51:47:09.5 | HIP 94266 | 15.92 |
| 2026-08-04 12:00 | 19:10:24.90 | +51:46:53.1 | HIP 94266 | 16.41 |
| 2026-08-05 00:00 | 19:10:21.38 | +51:46:36.5 | HIP 94266 | 16.91 |
| 2026-08-05 12:00 | 19:10:17.87 | +51:46:19.6 | HIP 94266 | 17.42 |
| 2026-08-06 00:00 | 19:10:14.39 | +51:46:02.5 | HIP 94266 | 17.93 |
| 2026-08-06 12:00 | 19:10:10.91 | +51:45:45.1 | HIP 94266 | 18.46 |
| 2026-08-07 00:00 | 19:10:07.46 | +51:45:27.4 | HIP 94266 | 18.99 |
| 2026-08-07 12:00 | 19:10:04.02 | +51:45:09.4 | HIP 94266 | 19.53 |
| 2026-08-08 00:00 | 19:10:00.60 | +51:44:51.1 | HIP 94266 | 20.08 |
| 2026-08-08 12:00 | 19:09:57.20 | +51:44:32.6 | HIP 94266 | 20.63 |
| 2026-08-09 00:00 | 19:09:53.81 | +51:44:13.8 | HIP 94266 | 21.19 |
| 2026-08-09 12:00 | 19:09:50.44 | +51:43:54.8 | HIP 94266 | 21.75 |
| 2026-08-10 00:00 | 19:09:47.09 | +51:43:35.5 | HIP 94266 | 22.32 |
| 2026-08-10 12:00 | 19:09:43.76 | +51:43:15.9 | HIP 94266 | 22.89 |
| 2026-08-11 00:00 | 19:09:40.45 | +51:42:56.1 | HIP 94266 | 23.46 |
| 2026-08-11 12:00 | 19:09:37.16 | +51:42:36.0 | HIP 93875 | 23.60 |
| 2026-08-12 00:00 | 19:09:33.88 | +51:42:15.6 | HIP 93875 | 23.06 |
| 2026-08-12 12:00 | 19:09:30.63 | +51:41:55.0 | HIP 93875 | 22.52 |
| 2026-08-13 00:00 | 19:09:27.39 | +51:41:34.1 | HIP 93875 | 21.98 |
| 2026-08-13 12:00 | 19:09:24.18 | +51:41:13.0 | HIP 93875 | 21.46 |
| 2026-08-14 00:00 | 19:09:20.99 | +51:40:51.6 | HIP 93875 | 20.94 |
| 2026-08-14 12:00 | 19:09:17.81 | +51:40:30.0 | HIP 93875 | 20.43 |
| 2026-08-15 00:00 | 19:09:14.66 | +51:40:08.1 | HIP 93875 | 19.93 |
| 2026-08-15 12:00 | 19:09:11.53 | +51:39:46.0 | HIP 93875 | 19.43 |
| 2026-08-16 00:00 | 19:09:08.42 | +51:39:23.7 | HIP 93875 | 18.95 |
| 2026-08-16 12:00 | 19:09:05.34 | +51:39:01.0 | HIP 93875 | 18.48 |
| 2026-08-17 00:00 | 19:09:02.27 | +51:38:38.2 | HIP 93875 | 18.02 |
| 2026-08-17 12:00 | 19:08:59.23 | +51:38:15.1 | HIP 93875 | 17.57 |
| 2026-08-18 00:00 | 19:08:56.21 | +51:37:51.8 | HIP 93875 | 17.13 |
| 2026-08-18 12:00 | 19:08:53.21 | +51:37:28.3 | HIP 93875 | 16.71 |
| 2026-08-19 00:00 | 19:08:50.24 | +51:37:04.5 | HIP 93875 | 16.31 |