| Parameter |
Value |
| Designation |
401P/McNaught |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2006-05-07T16:51:22.184640Z |
| Orbit solution date (soln_date, UTC) |
2024-06-03T15:49:51Z |
| Obs used |
268 |
| NEO |
- |
| M1 |
10.700 |
| K1 |
15.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2008-09-19.0000000 |
| e |
0.58200168 |
| q (au) |
2.379587 |
| a (au) |
5.692815 |
| i (deg) |
12.865037 |
| Ω (om, deg) |
0.095844 |
| ω (w, deg) |
310.243129 |
| M (ma, deg) |
62.788339 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.058 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.058 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.588 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
08:16:52.86 |
+30:05:02.9 |
HIP 40484 |
28.88 |
| 2026-05-12 12:00 |
08:17:00.27 |
+30:04:04.4 |
HIP 40484 |
28.70 |
| 2026-05-13 00:00 |
08:17:07.78 |
+30:03:05.7 |
HIP 40484 |
28.65 |
| 2026-05-13 12:00 |
08:17:15.38 |
+30:02:06.8 |
HIP 40484 |
28.74 |
| 2026-05-14 00:00 |
08:17:23.08 |
+30:01:07.8 |
HIP 40484 |
28.97 |
| 2026-05-14 12:00 |
08:17:30.88 |
+30:00:08.6 |
HIP 40484 |
29.33 |
| 2026-05-15 00:00 |
08:17:38.77 |
+29:59:09.3 |
HIP 40484 |
29.84 |
| 2026-05-15 12:00 |
08:17:46.76 |
+29:58:09.8 |
HIP 40484 |
30.48 |
| 2026-05-16 00:00 |
08:17:54.85 |
+29:57:10.2 |
HIP 40484 |
31.25 |
| 2026-05-16 12:00 |
08:18:03.03 |
+29:56:10.4 |
HIP 40484 |
32.14 |
| 2026-05-17 00:00 |
08:18:11.30 |
+29:55:10.4 |
HIP 40484 |
33.15 |
| 2026-05-17 12:00 |
08:18:19.66 |
+29:54:10.3 |
HIP 40484 |
34.27 |
| 2026-05-18 00:00 |
08:18:28.12 |
+29:53:10.1 |
HIP 40484 |
35.50 |
| 2026-05-18 12:00 |
08:18:36.67 |
+29:52:09.7 |
HIP 40484 |
36.82 |
| 2026-05-19 00:00 |
08:18:45.31 |
+29:51:09.2 |
HIP 40484 |
38.23 |
| 2026-05-19 12:00 |
08:18:54.03 |
+29:50:08.5 |
HIP 40484 |
39.73 |
| 2026-05-20 00:00 |
08:19:02.85 |
+29:49:07.7 |
HIP 40484 |
41.30 |
| 2026-05-20 12:00 |
08:19:11.76 |
+29:48:06.8 |
HIP 40484 |
42.94 |
| 2026-05-21 00:00 |
08:19:20.75 |
+29:47:05.7 |
HIP 40484 |
44.65 |
| 2026-05-21 12:00 |
08:19:29.83 |
+29:46:04.5 |
HIP 40676 |
44.46 |
| 2026-05-22 00:00 |
08:19:39.00 |
+29:45:03.2 |
HIP 40676 |
44.30 |
| 2026-05-22 12:00 |
08:19:48.25 |
+29:44:01.8 |
HIP 40676 |
44.27 |
| 2026-05-23 00:00 |
08:19:57.59 |
+29:43:00.2 |
HIP 40676 |
44.35 |
| 2026-05-23 12:00 |
08:20:07.01 |
+29:41:58.6 |
HIP 40676 |
44.56 |
| 2026-05-24 00:00 |
08:20:16.52 |
+29:40:56.8 |
HIP 40676 |
44.90 |
| 2026-05-24 12:00 |
08:20:26.11 |
+29:39:54.9 |
HIP 40676 |
45.37 |
| 2026-05-25 00:00 |
08:20:35.78 |
+29:38:52.8 |
HIP 40676 |
45.95 |
| 2026-05-25 12:00 |
08:20:45.53 |
+29:37:50.7 |
HIP 40676 |
46.66 |
| 2026-05-26 00:00 |
08:20:55.36 |
+29:36:48.4 |
HIP 41124 |
47.33 |
| 2026-05-26 12:00 |
08:21:05.27 |
+29:35:46.1 |
HIP 41124 |
46.62 |
| 2026-05-27 00:00 |
08:21:15.27 |
+29:34:43.6 |
HIP 40960 |
45.83 |
| 2026-05-27 12:00 |
08:21:25.34 |
+29:33:41.1 |
HIP 40960 |
44.65 |
| 2026-05-28 00:00 |
08:21:35.49 |
+29:32:38.4 |
HIP 40960 |
43.57 |
| 2026-05-28 12:00 |
08:21:45.71 |
+29:31:35.6 |
HIP 40960 |
42.60 |
| 2026-05-29 00:00 |
08:21:56.02 |
+29:30:32.7 |
HIP 40960 |
41.76 |
| 2026-05-29 12:00 |
08:22:06.40 |
+29:29:29.8 |
HIP 40960 |
41.04 |
| 2026-05-30 00:00 |
08:22:16.85 |
+29:28:26.7 |
HIP 40960 |
40.48 |
| 2026-05-30 12:00 |
08:22:27.39 |
+29:27:23.5 |
HIP 41283 |
39.22 |
| 2026-05-31 00:00 |
08:22:37.99 |
+29:26:20.3 |
HIP 41283 |
37.38 |
| 2026-05-31 12:00 |
08:22:48.67 |
+29:25:16.9 |
HIP 41283 |
35.60 |
| 2026-06-01 00:00 |
08:22:59.42 |
+29:24:13.5 |
HIP 41283 |
33.91 |
| 2026-06-01 12:00 |
08:23:10.25 |
+29:23:10.0 |
HIP 41283 |
32.32 |
| 2026-06-02 00:00 |
08:23:21.14 |
+29:22:06.4 |
HIP 41283 |
30.86 |