| 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) |
| 2026-09-20 00:00 |
09:14:16.31 |
+25:46:43.5 |
HIP 45260 |
23.25 |
| 2026-09-20 12:00 |
09:14:28.38 |
+25:46:07.2 |
HIP 45260 |
24.19 |
| 2026-09-21 00:00 |
09:14:40.40 |
+25:45:31.2 |
HIP 45260 |
25.40 |
| 2026-09-21 12:00 |
09:14:52.35 |
+25:44:55.6 |
HIP 45260 |
26.83 |
| 2026-09-22 00:00 |
09:15:04.24 |
+25:44:20.5 |
HIP 45260 |
28.46 |
| 2026-09-22 12:00 |
09:15:16.07 |
+25:43:45.7 |
HIP 45260 |
30.24 |
| 2026-09-23 00:00 |
09:15:27.84 |
+25:43:11.4 |
HIP 45316 |
31.20 |
| 2026-09-23 12:00 |
09:15:39.55 |
+25:42:37.4 |
HIP 45316 |
32.34 |
| 2026-09-24 00:00 |
09:15:51.19 |
+25:42:03.8 |
HIP 45612 |
32.76 |
| 2026-09-24 12:00 |
09:16:02.77 |
+25:41:30.7 |
HIP 45612 |
30.99 |
| 2026-09-25 00:00 |
09:16:14.29 |
+25:40:57.9 |
HIP 45612 |
29.37 |
| 2026-09-25 12:00 |
09:16:25.74 |
+25:40:25.6 |
HIP 45612 |
27.91 |
| 2026-09-26 00:00 |
09:16:37.13 |
+25:39:53.7 |
HIP 45612 |
26.64 |
| 2026-09-26 12:00 |
09:16:48.45 |
+25:39:22.2 |
HIP 45612 |
25.57 |
| 2026-09-27 00:00 |
09:16:59.70 |
+25:38:51.2 |
HIP 45612 |
24.73 |
| 2026-09-27 12:00 |
09:17:10.89 |
+25:38:20.5 |
HIP 45612 |
24.14 |
| 2026-09-28 00:00 |
09:17:22.01 |
+25:37:50.3 |
HIP 45612 |
23.81 |
| 2026-09-28 12:00 |
09:17:33.07 |
+25:37:20.5 |
HIP 45612 |
23.75 |
| 2026-09-29 00:00 |
09:17:44.05 |
+25:36:51.1 |
HIP 45612 |
23.95 |
| 2026-09-29 12:00 |
09:17:54.97 |
+25:36:22.2 |
HIP 45612 |
24.40 |
| 2026-09-30 00:00 |
09:18:05.82 |
+25:35:53.7 |
HIP 45665 |
23.98 |
| 2026-09-30 12:00 |
09:18:16.59 |
+25:35:25.6 |
HIP 45665 |
23.08 |
| 2026-10-01 00:00 |
09:18:27.30 |
+25:34:58.0 |
HIP 45665 |
22.43 |
| 2026-10-01 12:00 |
09:18:37.94 |
+25:34:30.9 |
HIP 45665 |
22.05 |
| 2026-10-02 00:00 |
09:18:48.50 |
+25:34:04.1 |
HIP 45665 |
21.93 |
| 2026-10-02 12:00 |
09:18:58.99 |
+25:33:37.9 |
HIP 45665 |
22.09 |
| 2026-10-03 00:00 |
09:19:09.41 |
+25:33:12.0 |
HIP 45665 |
22.50 |
| 2026-10-03 12:00 |
09:19:19.75 |
+25:32:46.7 |
HIP 45739 |
21.95 |
| 2026-10-04 00:00 |
09:19:30.02 |
+25:32:21.8 |
HIP 45739 |
21.41 |
| 2026-10-04 12:00 |
09:19:40.22 |
+25:31:57.3 |
HIP 45739 |
21.13 |
| 2026-10-05 00:00 |
09:19:50.34 |
+25:31:33.3 |
HIP 45739 |
21.10 |
| 2026-10-05 12:00 |
09:20:00.38 |
+25:31:09.8 |
HIP 45739 |
21.34 |
| 2026-10-06 00:00 |
09:20:10.35 |
+25:30:46.8 |
HIP 45897 |
19.67 |
| 2026-10-06 12:00 |
09:20:20.23 |
+25:30:24.2 |
HIP 45897 |
17.53 |
| 2026-10-07 00:00 |
09:20:30.04 |
+25:30:02.1 |
HIP 45897 |
15.46 |
| 2026-10-07 12:00 |
09:20:39.77 |
+25:29:40.5 |
HIP 45897 |
13.46 |
| 2026-10-08 00:00 |
09:20:49.42 |
+25:29:19.4 |
HIP 45897 |
11.55 |
| 2026-10-08 12:00 |
09:20:59.00 |
+25:28:58.7 |
HIP 45897 |
9.80 |
| 2026-10-09 00:00 |
09:21:08.49 |
+25:28:38.6 |
HIP 45897 |
8.27 |
| 2026-10-09 12:00 |
09:21:17.89 |
+25:28:18.9 |
HIP 45897 |
7.10 |
| 2026-10-10 00:00 |
09:21:27.22 |
+25:27:59.8 |
HIP 45897 |
6.46 |
| 2026-10-10 12:00 |
09:21:36.46 |
+25:27:41.1 |
HIP 45897 |
6.49 |
| 2026-10-11 00:00 |
09:21:45.62 |
+25:27:22.9 |
HIP 45897 |
7.17 |