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) |
|---|---|---|---|---|
| 2026-03-26 00:00 | 09:46:41.84 | +11:15:23.9 | HIP 48036 | 16.34 |
| 2026-03-26 12:00 | 09:46:28.59 | +11:16:49.5 | HIP 48036 | 18.23 |
| 2026-03-27 00:00 | 09:46:15.53 | +11:18:14.2 | HIP 48036 | 20.53 |
| 2026-03-27 12:00 | 09:46:02.66 | +11:19:37.8 | HIP 48036 | 23.08 |
| 2026-03-28 00:00 | 09:45:50.00 | +11:21:00.5 | HIP 48036 | 25.80 |
| 2026-03-28 12:00 | 09:45:37.53 | +11:22:22.1 | HIP 47959 | 28.53 |
| 2026-03-29 00:00 | 09:45:25.27 | +11:23:42.8 | HIP 47959 | 28.66 |
| 2026-03-29 12:00 | 09:45:13.20 | +11:25:02.4 | HIP 47959 | 29.16 |
| 2026-03-30 00:00 | 09:45:01.34 | +11:26:21.0 | HIP 47959 | 29.97 |
| 2026-03-30 12:00 | 09:44:49.69 | +11:27:38.6 | HIP 47959 | 31.06 |
| 2026-03-31 00:00 | 09:44:38.24 | +11:28:55.1 | HIP 47959 | 32.40 |
| 2026-03-31 12:00 | 09:44:27.00 | +11:30:10.6 | HIP 47959 | 33.92 |
| 2026-04-01 00:00 | 09:44:15.96 | +11:31:25.1 | HIP 47959 | 35.61 |
| 2026-04-01 12:00 | 09:44:05.14 | +11:32:38.5 | HIP 47720 | 37.33 |
| 2026-04-02 00:00 | 09:43:54.52 | +11:33:50.9 | HIP 47720 | 35.85 |
| 2026-04-02 12:00 | 09:43:44.12 | +11:35:02.2 | HIP 47720 | 34.55 |
| 2026-04-03 00:00 | 09:43:33.93 | +11:36:12.4 | HIP 47720 | 33.46 |
| 2026-04-03 12:00 | 09:43:23.95 | +11:37:21.6 | HIP 47720 | 32.57 |
| 2026-04-04 00:00 | 09:43:14.19 | +11:38:29.6 | HIP 47515 | 30.48 |
| 2026-04-04 12:00 | 09:43:04.64 | +11:39:36.6 | HIP 47515 | 28.40 |
| 2026-04-05 00:00 | 09:42:55.30 | +11:40:42.6 | HIP 47515 | 26.45 |
| 2026-04-05 12:00 | 09:42:46.19 | +11:41:47.4 | HIP 47515 | 24.66 |
| 2026-04-06 00:00 | 09:42:37.29 | +11:42:51.1 | HIP 47515 | 23.03 |
| 2026-04-06 12:00 | 09:42:28.61 | +11:43:53.8 | HIP 47515 | 21.59 |
| 2026-04-07 00:00 | 09:42:20.16 | +11:44:55.3 | HIP 47515 | 20.36 |
| 2026-04-07 12:00 | 09:42:11.92 | +11:45:55.7 | HIP 47515 | 19.36 |
| 2026-04-08 00:00 | 09:42:03.90 | +11:46:55.0 | HIP 47515 | 18.61 |
| 2026-04-08 12:00 | 09:41:56.11 | +11:47:53.2 | HIP 47515 | 18.11 |
| 2026-04-09 00:00 | 09:41:48.53 | +11:48:50.3 | HIP 47515 | 17.86 |
| 2026-04-09 12:00 | 09:41:41.19 | +11:49:46.3 | HIP 47515 | 17.87 |
| 2026-04-10 00:00 | 09:41:34.06 | +11:50:41.1 | HIP 47515 | 18.10 |
| 2026-04-10 12:00 | 09:41:27.16 | +11:51:34.8 | HIP 47515 | 18.53 |
| 2026-04-11 00:00 | 09:41:20.48 | +11:52:27.4 | HIP 47515 | 19.13 |
| 2026-04-11 12:00 | 09:41:14.03 | +11:53:18.8 | HIP 47515 | 19.87 |
| 2026-04-12 00:00 | 09:41:07.81 | +11:54:09.1 | HIP 47515 | 20.71 |
| 2026-04-12 12:00 | 09:41:01.81 | +11:54:58.2 | HIP 47515 | 21.64 |
| 2026-04-13 00:00 | 09:40:56.04 | +11:55:46.2 | HIP 47515 | 22.63 |
| 2026-04-13 12:00 | 09:40:50.50 | +11:56:33.1 | HIP 47515 | 23.65 |
| 2026-04-14 00:00 | 09:40:45.18 | +11:57:18.8 | HIP 47515 | 24.70 |
| 2026-04-14 12:00 | 09:40:40.10 | +11:58:03.4 | HIP 47515 | 25.77 |
| 2026-04-15 00:00 | 09:40:35.24 | +11:58:46.8 | HIP 47342 | 26.22 |
| 2026-04-15 12:00 | 09:40:30.61 | +11:59:29.0 | HIP 47342 | 24.99 |
| 2026-04-16 00:00 | 09:40:26.21 | +12:00:10.1 | HIP 47342 | 23.83 |