57P/duToit-Neujmin-Delporte
Metadata
| Parameter | Value |
|---|---|
| Designation | 57P/duToit-Neujmin-Delporte |
| Type | P |
| Perihelion (tp_cal, UTC) | 2015-05-22T12:24:41.207040Z |
| Orbit solution date (soln_date, UTC) | 2025-09-10T11:27:46Z |
| Obs used | 1389 |
| NEO | - |
| M1 | 15.800 |
| K1 | 4.500 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2018-03-03.0000000 |
| e | 0.49981547 |
| q (au) | 1.725627 |
| a (au) | 3.449981 |
| i (deg) | 2.848605 |
| Ω (om, deg) | 188.808603 |
| ω (w, deg) | 115.131778 |
| M (ma, deg) | 156.189430 |
Magnitude
Scatter + Global Linear
$$ M_a = (9.577 + 4.993\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 9.577 |
| n | 4.993 |
| gf | 1.000 |
| gb | -0.500 |
| k | 1.000 |
| 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 |
|---|---|---|---|
| 2019-12-04 | 2021-10-17 | +97.1837 | -24.683 |
| 2021-10-17 | 2023-02-09 | -17.9059 | +9.179 |
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 | 10:18:04.04 | +08:08:35.5 | HIP 50353 | 18.01 |
| 2026-02-03 12:00 | 10:17:46.11 | +08:10:17.7 | HIP 50353 | 13.26 |
| 2026-02-04 00:00 | 10:17:28.06 | +08:12:00.6 | HIP 50353 | 8.48 |
| 2026-02-04 12:00 | 10:17:09.90 | +08:13:44.4 | HIP 50353 | 3.67 |
| 2026-02-05 00:00 | 10:16:51.61 | +08:15:28.8 | HIP 50353 | 1.25 |
| 2026-02-05 12:00 | 10:16:33.22 | +08:17:14.1 | HIP 50353 | 6.08 |
| 2026-02-06 00:00 | 10:16:14.71 | +08:19:00.0 | HIP 50353 | 10.99 |
| 2026-02-06 12:00 | 10:15:56.10 | +08:20:46.7 | HIP 50353 | 15.92 |
| 2026-02-07 00:00 | 10:15:37.38 | +08:22:34.0 | HIP 50353 | 20.88 |
| 2026-02-07 12:00 | 10:15:18.57 | +08:24:22.0 | HIP 50172 | 17.84 |
| 2026-02-08 00:00 | 10:14:59.65 | +08:26:10.7 | HIP 50172 | 13.45 |
| 2026-02-08 12:00 | 10:14:40.64 | +08:28:00.0 | HIP 50172 | 9.67 |
| 2026-02-09 00:00 | 10:14:21.54 | +08:29:50.0 | HIP 50172 | 7.54 |
| 2026-02-09 12:00 | 10:14:02.35 | +08:31:40.5 | HIP 50172 | 8.47 |
| 2026-02-10 00:00 | 10:13:43.07 | +08:33:31.7 | HIP 50089 | 9.06 |
| 2026-02-10 12:00 | 10:13:23.71 | +08:35:23.4 | HIP 50089 | 11.42 |
| 2026-02-11 00:00 | 10:13:04.28 | +08:37:15.6 | HIP 50089 | 15.23 |
| 2026-02-11 12:00 | 10:12:44.76 | +08:39:08.4 | HIP 50089 | 19.68 |
| 2026-02-12 00:00 | 10:12:25.18 | +08:41:01.6 | HIP 49895 | 23.27 |
| 2026-02-12 12:00 | 10:12:05.52 | +08:42:55.4 | HIP 49895 | 18.47 |
| 2026-02-13 00:00 | 10:11:45.80 | +08:44:49.6 | HIP 49895 | 13.94 |
| 2026-02-13 12:00 | 10:11:26.02 | +08:46:44.3 | HIP 49895 | 10.12 |
| 2026-02-14 00:00 | 10:11:06.18 | +08:48:39.4 | HIP 49895 | 8.08 |
| 2026-02-14 12:00 | 10:10:46.28 | +08:50:34.9 | HIP 49895 | 9.15 |
| 2026-02-15 00:00 | 10:10:26.33 | +08:52:30.8 | HIP 49895 | 12.58 |
| 2026-02-15 12:00 | 10:10:06.34 | +08:54:27.1 | HIP 49895 | 17.00 |
| 2026-02-16 00:00 | 10:09:46.30 | +08:56:23.7 | HIP 49895 | 21.83 |
| 2026-02-16 12:00 | 10:09:26.22 | +08:58:20.6 | HIP 49895 | 26.85 |
| 2026-02-17 00:00 | 10:09:06.10 | +09:00:17.9 | HIP 49895 | 31.98 |
| 2026-02-17 12:00 | 10:08:45.95 | +09:02:15.4 | HIP 49562 | 29.09 |
| 2026-02-18 00:00 | 10:08:25.77 | +09:04:13.1 | HIP 49562 | 26.40 |
| 2026-02-18 12:00 | 10:08:05.56 | +09:06:11.1 | HIP 49562 | 24.58 |
| 2026-02-19 00:00 | 10:07:45.34 | +09:08:09.3 | HIP 49562 | 23.87 |
| 2026-02-19 12:00 | 10:07:25.09 | +09:10:07.7 | HIP 49562 | 24.35 |
| 2026-02-20 00:00 | 10:07:04.83 | +09:12:06.3 | HIP 49492 | 25.20 |
| 2026-02-20 12:00 | 10:06:44.56 | +09:14:05.0 | HIP 49492 | 25.07 |
| 2026-02-21 00:00 | 10:06:24.28 | +09:16:03.9 | HIP 49492 | 26.09 |
| 2026-02-21 12:00 | 10:06:04.00 | +09:18:02.8 | HIP 49492 | 28.11 |
| 2026-02-22 00:00 | 10:05:43.72 | +09:20:01.8 | HIP 49492 | 30.96 |
| 2026-02-22 12:00 | 10:05:23.44 | +09:22:00.9 | HIP 49492 | 34.41 |
| 2026-02-23 00:00 | 10:05:03.18 | +09:24:00.0 | HIP 49279 | 37.25 |
| 2026-02-23 12:00 | 10:04:42.92 | +09:25:59.2 | HIP 49279 | 32.81 |
| 2026-02-24 00:00 | 10:04:22.68 | +09:27:58.3 | HIP 49279 | 28.69 |