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 | -0.998 |
| 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 | +97.4882 | -24.758 |
| 2021-10-17 | 2023-02-09 | -17.3894 | +9.053 |
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 | 10:30:35.61 | +08:16:00.3 | HIP 51396 | 17.41 |
| 2026-07-29 12:00 | 10:31:02.41 | +08:13:32.7 | HIP 51396 | 20.86 |
| 2026-07-30 00:00 | 10:31:29.27 | +08:11:04.4 | HIP 51571 | 21.07 |
| 2026-07-30 12:00 | 10:31:56.20 | +08:08:35.6 | HIP 51571 | 22.10 |
| 2026-07-31 00:00 | 10:32:23.19 | +08:06:06.2 | HIP 51571 | 25.19 |
| 2026-07-31 12:00 | 10:32:50.24 | +08:03:36.3 | HIP 51571 | 29.71 |
| 2026-08-01 00:00 | 10:33:17.34 | +08:01:05.8 | HIP 51787 | 23.90 |
| 2026-08-01 12:00 | 10:33:44.51 | +07:58:34.8 | HIP 51787 | 17.82 |
| 2026-08-02 00:00 | 10:34:11.74 | +07:56:03.2 | HIP 51787 | 12.91 |
| 2026-08-02 12:00 | 10:34:39.02 | +07:53:31.1 | HIP 51787 | 10.93 |
| 2026-08-03 00:00 | 10:35:06.36 | +07:50:58.5 | HIP 51787 | 13.30 |
| 2026-08-03 12:00 | 10:35:33.76 | +07:48:25.3 | HIP 51787 | 18.42 |
| 2026-08-04 00:00 | 10:36:01.22 | +07:45:51.5 | HIP 51787 | 24.65 |
| 2026-08-04 12:00 | 10:36:28.73 | +07:43:17.3 | HIP 51922 | 27.18 |
| 2026-08-05 00:00 | 10:36:56.30 | +07:40:42.5 | HIP 51922 | 30.81 |
| 2026-08-05 12:00 | 10:37:23.92 | +07:38:07.2 | HIP 52122 | 28.06 |
| 2026-08-06 00:00 | 10:37:51.60 | +07:35:31.3 | HIP 52122 | 21.09 |
| 2026-08-06 12:00 | 10:38:19.33 | +07:32:54.9 | HIP 52122 | 14.48 |
| 2026-08-07 00:00 | 10:38:47.12 | +07:30:18.0 | HIP 52122 | 9.07 |
| 2026-08-07 12:00 | 10:39:14.96 | +07:27:40.6 | HIP 52164 | 3.61 |
| 2026-08-08 00:00 | 10:39:42.85 | +07:25:02.7 | HIP 52164 | 3.97 |
| 2026-08-08 12:00 | 10:40:10.80 | +07:22:24.3 | HIP 52164 | 11.33 |
| 2026-08-09 00:00 | 10:40:38.79 | +07:19:45.3 | HIP 52164 | 18.74 |
| 2026-08-09 12:00 | 10:41:06.84 | +07:17:05.9 | HIP 52360 | 19.76 |
| 2026-08-10 00:00 | 10:41:34.94 | +07:14:26.0 | HIP 52360 | 17.82 |
| 2026-08-10 12:00 | 10:42:03.09 | +07:11:45.5 | HIP 52360 | 18.87 |
| 2026-08-11 00:00 | 10:42:31.29 | +07:09:04.6 | HIP 52360 | 22.51 |
| 2026-08-11 12:00 | 10:42:59.54 | +07:06:23.2 | HIP 52389 | 27.18 |
| 2026-08-12 00:00 | 10:43:27.83 | +07:03:41.3 | HIP 52389 | 27.50 |
| 2026-08-12 12:00 | 10:43:56.18 | +07:00:58.9 | HIP 52598 | 20.79 |
| 2026-08-13 00:00 | 10:44:24.57 | +06:58:16.0 | HIP 52598 | 13.49 |
| 2026-08-13 12:00 | 10:44:53.00 | +06:55:32.7 | HIP 52598 | 6.76 |
| 2026-08-14 00:00 | 10:45:21.48 | +06:52:48.9 | HIP 52598 | 4.88 |
| 2026-08-14 12:00 | 10:45:50.01 | +06:50:04.7 | HIP 52598 | 10.82 |
| 2026-08-15 00:00 | 10:46:18.58 | +06:47:20.0 | HIP 52598 | 18.06 |
| 2026-08-15 12:00 | 10:46:47.20 | +06:44:34.8 | HIP 52837 | 21.46 |
| 2026-08-16 00:00 | 10:47:15.85 | +06:41:49.2 | HIP 52837 | 15.22 |
| 2026-08-16 12:00 | 10:47:44.55 | +06:39:03.1 | HIP 52837 | 10.93 |
| 2026-08-17 00:00 | 10:48:13.29 | +06:36:16.6 | HIP 52837 | 11.14 |
| 2026-08-17 12:00 | 10:48:42.08 | +06:33:29.7 | HIP 52917 | 14.81 |
| 2026-08-18 00:00 | 10:49:10.90 | +06:30:42.3 | HIP 52917 | 14.04 |
| 2026-08-18 12:00 | 10:49:39.76 | +06:27:54.6 | HIP 52917 | 17.12 |
| 2026-08-19 00:00 | 10:50:08.67 | +06:25:06.4 | HIP 52917 | 22.54 |