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) |
|---|---|---|---|---|
| 2026-05-12 00:00 | 09:41:46.27 | +12:09:19.4 | HIP 47720 | 28.60 |
| 2026-05-12 12:00 | 09:41:53.47 | +12:09:00.3 | HIP 47720 | 26.85 |
| 2026-05-13 00:00 | 09:42:00.87 | +12:08:40.1 | HIP 47720 | 25.05 |
| 2026-05-13 12:00 | 09:42:08.46 | +12:08:18.9 | HIP 47720 | 23.21 |
| 2026-05-14 00:00 | 09:42:16.26 | +12:07:56.6 | HIP 47720 | 21.34 |
| 2026-05-14 12:00 | 09:42:24.25 | +12:07:33.2 | HIP 47720 | 19.43 |
| 2026-05-15 00:00 | 09:42:32.45 | +12:07:08.7 | HIP 47720 | 17.49 |
| 2026-05-15 12:00 | 09:42:40.83 | +12:06:43.2 | HIP 47720 | 15.53 |
| 2026-05-16 00:00 | 09:42:49.42 | +12:06:16.6 | HIP 47720 | 13.58 |
| 2026-05-16 12:00 | 09:42:58.20 | +12:05:48.9 | HIP 47720 | 11.65 |
| 2026-05-17 00:00 | 09:43:07.17 | +12:05:20.1 | HIP 47720 | 9.80 |
| 2026-05-17 12:00 | 09:43:16.33 | +12:04:50.3 | HIP 47720 | 8.12 |
| 2026-05-18 00:00 | 09:43:25.69 | +12:04:19.5 | HIP 47720 | 6.80 |
| 2026-05-18 12:00 | 09:43:35.24 | +12:03:47.6 | HIP 47720 | 6.12 |
| 2026-05-19 00:00 | 09:43:44.97 | +12:03:14.6 | HIP 47720 | 6.36 |
| 2026-05-19 12:00 | 09:43:54.90 | +12:02:40.6 | HIP 47720 | 7.47 |
| 2026-05-20 00:00 | 09:44:05.01 | +12:02:05.5 | HIP 47720 | 9.18 |
| 2026-05-20 12:00 | 09:44:15.30 | +12:01:29.5 | HIP 47720 | 11.26 |
| 2026-05-21 00:00 | 09:44:25.79 | +12:00:52.3 | HIP 47720 | 13.56 |
| 2026-05-21 12:00 | 09:44:36.45 | +12:00:14.2 | HIP 47720 | 16.01 |
| 2026-05-22 00:00 | 09:44:47.30 | +11:59:35.0 | HIP 47720 | 18.57 |
| 2026-05-22 12:00 | 09:44:58.33 | +11:58:54.8 | HIP 47720 | 21.22 |
| 2026-05-23 00:00 | 09:45:09.54 | +11:58:13.6 | HIP 47959 | 20.46 |
| 2026-05-23 12:00 | 09:45:20.93 | +11:57:31.3 | HIP 47959 | 17.68 |
| 2026-05-24 00:00 | 09:45:32.50 | +11:56:48.1 | HIP 47959 | 14.90 |
| 2026-05-24 12:00 | 09:45:44.24 | +11:56:03.9 | HIP 47959 | 12.13 |
| 2026-05-25 00:00 | 09:45:56.16 | +11:55:18.6 | HIP 47959 | 9.45 |
| 2026-05-25 12:00 | 09:46:08.26 | +11:54:32.4 | HIP 47959 | 6.99 |
| 2026-05-26 00:00 | 09:46:20.52 | +11:53:45.1 | HIP 47959 | 5.20 |
| 2026-05-26 12:00 | 09:46:32.96 | +11:52:56.9 | HIP 47959 | 4.95 |
| 2026-05-27 00:00 | 09:46:45.57 | +11:52:07.7 | HIP 47978 | 2.98 |
| 2026-05-27 12:00 | 09:46:58.35 | +11:51:17.5 | HIP 47978 | 3.55 |
| 2026-05-28 00:00 | 09:47:11.30 | +11:50:26.4 | HIP 47978 | 6.15 |
| 2026-05-28 12:00 | 09:47:24.42 | +11:49:34.2 | HIP 47978 | 9.23 |
| 2026-05-29 00:00 | 09:47:37.70 | +11:48:41.1 | HIP 47978 | 12.48 |
| 2026-05-29 12:00 | 09:47:51.15 | +11:47:47.0 | HIP 48029 | 15.01 |
| 2026-05-30 00:00 | 09:48:04.76 | +11:46:52.0 | HIP 48029 | 15.92 |
| 2026-05-30 12:00 | 09:48:18.54 | +11:45:56.0 | HIP 48029 | 17.49 |
| 2026-05-31 00:00 | 09:48:32.48 | +11:44:59.1 | HIP 48029 | 19.59 |
| 2026-05-31 12:00 | 09:48:46.58 | +11:44:01.2 | HIP 48161 | 22.01 |
| 2026-06-01 00:00 | 09:49:00.84 | +11:43:02.3 | HIP 48161 | 22.74 |
| 2026-06-01 12:00 | 09:49:15.26 | +11:42:02.5 | HIP 48161 | 24.03 |
| 2026-06-02 00:00 | 09:49:29.84 | +11:41:01.8 | HIP 48298 | 21.65 |