378P/McNaught
Metadata
| Parameter | Value |
|---|---|
| Designation | 378P/McNaught |
| Type | P |
| Perihelion (tp_cal, UTC) | 2020-10-21T12:01:27.851520Z |
| Orbit solution date (soln_date, UTC) | 2026-01-13T08:12:54Z |
| Obs used | 828 |
| NEO | - |
| M1 | 12.200 |
| K1 | 4.500 |
| PC | - |
| Discovery observation (MPC, UTC) | 2019-03-10T03:16:12.864000Z |
| Discovery magnitude (MPC) | 21.90 G |
| Discovery observatory (MPC) | J04 · ESA Optical Ground Station, Tenerife |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2020-05-16.0000000 |
| e | 0.46883776 |
| q (au) | 3.380503 |
| a (au) | 6.364351 |
| i (deg) | 19.108649 |
| Ω (om, deg) | 94.516291 |
| ω (w, deg) | 194.158503 |
| M (ma, deg) | 350.270176 |
Magnitude
Scatter + Global Linear
$$ M_a = (15.990 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 15.990 |
| n | 2.000 |
| gf | 0.993 |
| gb | -0.828 |
| k | 0.800 |
| 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 |
|---|---|---|---|
| 2019-02-17 | 2020-04-05 | +16.4000 | -8.371 |
| 2021-04-03 | 2021-09-29 | -16.9920 | +11.467 |
| 2021-09-29 | 2022-12-16 | -7.8118 | +5.383 |
| 2022-12-16 | 2023-12-10 | +7.1269 | -6.004 |
| 2023-12-10 | 2026-01-12 | +4.0390 | -3.670 |
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 | 05:24:14.95 | +20:25:41.0 | HIP 25230 | 11.36 |
| 2026-05-12 12:00 | 05:24:29.40 | +20:26:13.6 | HIP 25337 | 13.02 |
| 2026-05-13 00:00 | 05:24:43.90 | +20:26:46.1 | HIP 25337 | 10.32 |
| 2026-05-13 12:00 | 05:24:58.44 | +20:27:18.5 | HIP 25337 | 8.21 |
| 2026-05-14 00:00 | 05:25:13.02 | +20:27:50.7 | HIP 25337 | 7.21 |
| 2026-05-14 12:00 | 05:25:27.65 | +20:28:22.9 | HIP 25337 | 7.78 |
| 2026-05-15 00:00 | 05:25:42.31 | +20:28:54.8 | HIP 25337 | 9.66 |
| 2026-05-15 12:00 | 05:25:57.02 | +20:29:26.7 | HIP 25337 | 12.26 |
| 2026-05-16 00:00 | 05:26:11.77 | +20:29:58.4 | HIP 25337 | 15.23 |
| 2026-05-16 12:00 | 05:26:26.55 | +20:30:30.0 | HIP 25337 | 18.40 |
| 2026-05-17 00:00 | 05:26:41.38 | +20:31:01.5 | HIP 25337 | 21.67 |
| 2026-05-17 12:00 | 05:26:56.24 | +20:31:32.8 | HIP 25337 | 25.02 |
| 2026-05-18 00:00 | 05:27:11.14 | +20:32:04.0 | HIP 25668 | 25.64 |
| 2026-05-18 12:00 | 05:27:26.08 | +20:32:35.1 | HIP 25668 | 22.37 |
| 2026-05-19 00:00 | 05:27:41.05 | +20:33:06.0 | HIP 25668 | 19.19 |
| 2026-05-19 12:00 | 05:27:56.05 | +20:33:36.8 | HIP 25668 | 16.15 |
| 2026-05-20 00:00 | 05:28:11.10 | +20:34:07.4 | HIP 25668 | 13.36 |
| 2026-05-20 12:00 | 05:28:26.17 | +20:34:37.9 | HIP 25668 | 11.02 |
| 2026-05-21 00:00 | 05:28:41.28 | +20:35:08.2 | HIP 25668 | 9.47 |
| 2026-05-21 12:00 | 05:28:56.42 | +20:35:38.5 | HIP 25668 | 9.14 |
| 2026-05-22 00:00 | 05:29:11.59 | +20:36:08.5 | HIP 25668 | 10.14 |
| 2026-05-22 12:00 | 05:29:26.79 | +20:36:38.5 | HIP 25777 | 11.84 |
| 2026-05-23 00:00 | 05:29:42.02 | +20:37:08.2 | HIP 25777 | 8.72 |
| 2026-05-23 12:00 | 05:29:57.29 | +20:37:37.9 | HIP 25777 | 6.15 |
| 2026-05-24 00:00 | 05:30:12.58 | +20:38:07.4 | HIP 25777 | 5.06 |
| 2026-05-24 12:00 | 05:30:27.90 | +20:38:36.7 | HIP 25777 | 6.28 |
| 2026-05-25 00:00 | 05:30:43.24 | +20:39:05.9 | HIP 25777 | 8.92 |
| 2026-05-25 12:00 | 05:30:58.62 | +20:39:35.0 | HIP 25777 | 12.08 |
| 2026-05-26 00:00 | 05:31:14.02 | +20:40:03.9 | HIP 25777 | 15.45 |
| 2026-05-26 12:00 | 05:31:29.44 | +20:40:32.7 | HIP 25777 | 18.93 |
| 2026-05-27 00:00 | 05:31:44.89 | +20:41:01.3 | HIP 25777 | 22.46 |
| 2026-05-27 12:00 | 05:32:00.37 | +20:41:29.8 | HIP 25936 | 21.98 |
| 2026-05-28 00:00 | 05:32:15.87 | +20:41:58.1 | HIP 25936 | 21.60 |
| 2026-05-28 12:00 | 05:32:31.39 | +20:42:26.3 | HIP 26072 | 21.09 |
| 2026-05-29 00:00 | 05:32:46.94 | +20:42:54.3 | HIP 26072 | 18.88 |
| 2026-05-29 12:00 | 05:33:02.51 | +20:43:22.1 | HIP 26072 | 17.17 |
| 2026-05-30 00:00 | 05:33:18.10 | +20:43:49.9 | HIP 26072 | 16.12 |
| 2026-05-30 12:00 | 05:33:33.71 | +20:44:17.4 | HIP 26072 | 15.88 |
| 2026-05-31 00:00 | 05:33:49.35 | +20:44:44.8 | HIP 26072 | 16.48 |
| 2026-05-31 12:00 | 05:34:05.00 | +20:45:12.1 | HIP 26072 | 17.83 |
| 2026-06-01 00:00 | 05:34:20.67 | +20:45:39.2 | HIP 26072 | 19.79 |
| 2026-06-01 12:00 | 05:34:36.37 | +20:46:06.2 | HIP 26072 | 22.20 |
| 2026-06-02 00:00 | 05:34:52.08 | +20:46:33.0 | HIP 26281 | 23.84 |