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 | 1.000 |
| 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 | +16.4009 | -8.371 |
| 2021-04-03 | 2021-09-29 | -16.9913 | +11.467 |
| 2021-09-29 | 2022-12-16 | -7.8113 | +5.383 |
| 2022-12-16 | 2023-12-10 | +7.1275 | -6.004 |
| 2023-12-10 | 2026-01-12 | +4.0394 | -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) |
|---|---|---|---|---|
| 2026-06-01 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 |
| 2026-06-02 12:00 | 05:35:07.80 | +20:46:59.6 | HIP 26281 | 22.54 |
| 2026-06-03 00:00 | 05:35:23.55 | +20:47:26.1 | HIP 26281 | 21.79 |
| 2026-06-03 12:00 | 05:35:39.31 | +20:47:52.5 | HIP 26381 | 19.85 |
| 2026-06-04 00:00 | 05:35:55.09 | +20:48:18.7 | HIP 26381 | 16.37 |
| 2026-06-04 12:00 | 05:36:10.89 | +20:48:44.7 | HIP 26381 | 13.01 |
| 2026-06-05 00:00 | 05:36:26.70 | +20:49:10.6 | HIP 26381 | 9.90 |
| 2026-06-05 12:00 | 05:36:42.52 | +20:49:36.3 | HIP 26381 | 7.37 |
| 2026-06-06 00:00 | 05:36:58.36 | +20:50:01.8 | HIP 26381 | 6.20 |
| 2026-06-06 12:00 | 05:37:14.21 | +20:50:27.3 | HIP 26381 | 7.09 |
| 2026-06-07 00:00 | 05:37:30.07 | +20:50:52.5 | HIP 26381 | 9.48 |
| 2026-06-07 12:00 | 05:37:45.95 | +20:51:17.6 | HIP 26381 | 12.55 |
| 2026-06-08 00:00 | 05:38:01.84 | +20:51:42.5 | HIP 26381 | 15.90 |
| 2026-06-08 12:00 | 05:38:17.74 | +20:52:07.3 | HIP 26451 | 18.79 |
| 2026-06-09 00:00 | 05:38:33.65 | +20:52:31.9 | HIP 26451 | 20.53 |
| 2026-06-09 12:00 | 05:38:49.57 | +20:52:56.4 | HIP 26451 | 22.75 |
| 2026-06-10 00:00 | 05:39:05.50 | +20:53:20.7 | HIP 26451 | 25.34 |
| 2026-06-10 12:00 | 05:39:21.44 | +20:53:44.8 | HIP 26684 | 26.43 |
| 2026-06-11 00:00 | 05:39:37.39 | +20:54:08.8 | HIP 26684 | 24.55 |
| 2026-06-11 12:00 | 05:39:53.35 | +20:54:32.6 | HIP 26684 | 23.13 |
| 2026-06-12 00:00 | 05:40:09.31 | +20:54:56.3 | HIP 26684 | 22.25 |
| 2026-06-12 12:00 | 05:40:25.28 | +20:55:19.8 | HIP 26684 | 21.99 |
| 2026-06-13 00:00 | 05:40:41.25 | +20:55:43.1 | HIP 26696 | 22.31 |
| 2026-06-13 12:00 | 05:40:57.23 | +20:56:06.3 | HIP 26696 | 22.88 |
| 2026-06-14 00:00 | 05:41:13.22 | +20:56:29.3 | HIP 26696 | 24.02 |
| 2026-06-14 12:00 | 05:41:29.20 | +20:56:52.1 | HIP 26880 | 23.92 |
| 2026-06-15 00:00 | 05:41:45.19 | +20:57:14.8 | HIP 26880 | 22.46 |
| 2026-06-15 12:00 | 05:42:01.19 | +20:57:37.4 | HIP 26880 | 21.57 |
| 2026-06-16 00:00 | 05:42:17.18 | +20:57:59.7 | HIP 26880 | 21.31 |
| 2026-06-16 12:00 | 05:42:33.18 | +20:58:21.9 | HIP 26880 | 21.70 |
| 2026-06-17 00:00 | 05:42:49.17 | +20:58:44.0 | HIP 26880 | 22.71 |
| 2026-06-17 12:00 | 05:43:05.17 | +20:59:05.9 | HIP 26880 | 24.26 |
| 2026-06-18 00:00 | 05:43:21.16 | +20:59:27.6 | HIP 26912 | 25.06 |
| 2026-06-18 12:00 | 05:43:37.15 | +20:59:49.2 | HIP 26967 | 25.39 |
| 2026-06-19 00:00 | 05:43:53.14 | +21:00:10.6 | HIP 26967 | 25.83 |
| 2026-06-19 12:00 | 05:44:09.13 | +21:00:31.8 | HIP 26967 | 26.79 |
| 2026-06-20 00:00 | 05:44:25.11 | +21:00:52.9 | HIP 27181 | 25.87 |
| 2026-06-20 12:00 | 05:44:41.09 | +21:01:13.8 | HIP 27181 | 23.81 |
| 2026-06-21 00:00 | 05:44:57.07 | +21:01:34.6 | HIP 27214 | 22.01 |
| 2026-06-21 12:00 | 05:45:13.03 | +21:01:55.2 | HIP 27214 | 19.28 |
| 2026-06-22 00:00 | 05:45:29.00 | +21:02:15.6 | HIP 27214 | 16.95 |