| Parameter |
Value |
| Designation |
P/2011 P1 (McNaught) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2010-07-24T04:00:53.856000Z |
| Orbit solution date (soln_date, UTC) |
2022-03-08T19:43:47Z |
| Obs used |
156 |
| NEO |
- |
| M1 |
6.800 |
| K1 |
11.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-08-20.0000000 |
| e |
0.36688593 |
| q (au) |
4.952165 |
| a (au) |
7.821915 |
| i (deg) |
6.308803 |
| Ω (om, deg) |
10.081774 |
| ω (w, deg) |
342.119808 |
| M (ma, deg) |
17.653674 |
Magnitude
Scatter + Global Linear
$$
M_a = (3.503 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
3.503 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.623 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
15:22:59.53 |
-23:08:21.8 |
HIP 75270 |
14.86 |
| 2026-09-20 12:00 |
15:23:13.10 |
-23:09:00.8 |
HIP 75270 |
16.50 |
| 2026-09-21 00:00 |
15:23:26.76 |
-23:09:40.1 |
HIP 75270 |
18.57 |
| 2026-09-21 12:00 |
15:23:40.51 |
-23:10:19.7 |
HIP 75393 |
18.08 |
| 2026-09-22 00:00 |
15:23:54.35 |
-23:10:59.7 |
HIP 75454 |
17.28 |
| 2026-09-22 12:00 |
15:24:08.28 |
-23:11:40.0 |
HIP 75454 |
14.41 |
| 2026-09-23 00:00 |
15:24:22.30 |
-23:12:20.6 |
HIP 75454 |
11.73 |
| 2026-09-23 12:00 |
15:24:36.40 |
-23:13:01.5 |
HIP 75454 |
9.44 |
| 2026-09-24 00:00 |
15:24:50.59 |
-23:13:42.8 |
HIP 75454 |
7.89 |
| 2026-09-24 12:00 |
15:25:04.87 |
-23:14:24.4 |
HIP 75454 |
7.60 |
| 2026-09-25 00:00 |
15:25:19.23 |
-23:15:06.3 |
HIP 75454 |
8.71 |
| 2026-09-25 12:00 |
15:25:33.68 |
-23:15:48.5 |
HIP 75454 |
10.81 |
| 2026-09-26 00:00 |
15:25:48.22 |
-23:16:31.0 |
HIP 75578 |
10.11 |
| 2026-09-26 12:00 |
15:26:02.83 |
-23:17:13.9 |
HIP 75578 |
7.36 |
| 2026-09-27 00:00 |
15:26:17.54 |
-23:17:57.0 |
HIP 75578 |
5.43 |
| 2026-09-27 12:00 |
15:26:32.32 |
-23:18:40.4 |
HIP 75578 |
5.36 |
| 2026-09-28 00:00 |
15:26:47.19 |
-23:19:24.2 |
HIP 75578 |
7.23 |
| 2026-09-28 12:00 |
15:27:02.14 |
-23:20:08.2 |
HIP 75578 |
10.02 |
| 2026-09-29 00:00 |
15:27:17.17 |
-23:20:52.5 |
HIP 75578 |
13.18 |
| 2026-09-29 12:00 |
15:27:32.28 |
-23:21:37.1 |
HIP 75578 |
16.50 |
| 2026-09-30 00:00 |
15:27:47.48 |
-23:22:22.0 |
HIP 75578 |
19.92 |
| 2026-09-30 12:00 |
15:28:02.75 |
-23:23:07.2 |
HIP 75578 |
23.41 |
| 2026-10-01 00:00 |
15:28:18.10 |
-23:23:52.6 |
HIP 75801 |
21.47 |
| 2026-10-01 12:00 |
15:28:33.54 |
-23:24:38.4 |
HIP 75801 |
19.10 |
| 2026-10-02 00:00 |
15:28:49.05 |
-23:25:24.4 |
HIP 75801 |
17.15 |
| 2026-10-02 12:00 |
15:29:04.64 |
-23:26:10.7 |
HIP 75801 |
15.81 |
| 2026-10-03 00:00 |
15:29:20.31 |
-23:26:57.2 |
HIP 75801 |
15.24 |
| 2026-10-03 12:00 |
15:29:36.06 |
-23:27:44.1 |
HIP 75801 |
15.55 |
| 2026-10-04 00:00 |
15:29:51.88 |
-23:28:31.1 |
HIP 75801 |
16.70 |
| 2026-10-04 12:00 |
15:30:07.78 |
-23:29:18.5 |
HIP 75801 |
18.54 |
| 2026-10-05 00:00 |
15:30:23.75 |
-23:30:06.1 |
HIP 75801 |
20.90 |
| 2026-10-05 12:00 |
15:30:39.80 |
-23:30:54.0 |
HIP 75801 |
23.64 |
| 2026-10-06 00:00 |
15:30:55.93 |
-23:31:42.1 |
HIP 76101 |
23.26 |
| 2026-10-06 12:00 |
15:31:12.13 |
-23:32:30.5 |
HIP 76101 |
19.95 |
| 2026-10-07 00:00 |
15:31:28.40 |
-23:33:19.1 |
HIP 76101 |
16.85 |
| 2026-10-07 12:00 |
15:31:44.75 |
-23:34:08.0 |
HIP 76101 |
14.09 |
| 2026-10-08 00:00 |
15:32:01.17 |
-23:34:57.1 |
HIP 76101 |
11.93 |
| 2026-10-08 12:00 |
15:32:17.66 |
-23:35:46.4 |
HIP 76101 |
10.76 |
| 2026-10-09 00:00 |
15:32:34.22 |
-23:36:36.0 |
HIP 76101 |
10.92 |
| 2026-10-09 12:00 |
15:32:50.85 |
-23:37:25.8 |
HIP 76155 |
11.11 |
| 2026-10-10 00:00 |
15:33:07.55 |
-23:38:15.8 |
HIP 76155 |
10.53 |
| 2026-10-10 12:00 |
15:33:24.33 |
-23:39:06.1 |
HIP 76155 |
11.37 |
| 2026-10-11 00:00 |
15:33:41.17 |
-23:39:56.6 |
HIP 76155 |
13.37 |