| Parameter |
Value |
| Designation |
C/2007 P1 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2007-04-03T06:43:48.607680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:10Z |
| Obs used |
16 |
| NEO |
- |
| M1 |
13.600 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2007-08-10.0000000 |
| e |
1.00042564 |
| q (au) |
0.522246 |
| a (au) |
-1226.959668 |
| i (deg) |
119.181662 |
| Ω (om, deg) |
187.061353 |
| ω (w, deg) |
90.192851 |
| M (ma, deg) |
0.002952 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.762 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.762 |
| n |
2.000 |
| gf |
0.999 |
| gb |
-1.000 |
| 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) |
| 2026-06-01 00:00 |
23:23:13.39 |
-72:45:41.6 |
HIP 115757 |
18.73 |
| 2026-06-01 12:00 |
23:23:14.88 |
-72:46:22.4 |
HIP 115757 |
18.37 |
| 2026-06-02 00:00 |
23:23:16.28 |
-72:47:03.3 |
HIP 115757 |
18.03 |
| 2026-06-02 12:00 |
23:23:17.62 |
-72:47:44.3 |
HIP 115757 |
17.73 |
| 2026-06-03 00:00 |
23:23:18.88 |
-72:48:25.4 |
HIP 115757 |
17.44 |
| 2026-06-03 12:00 |
23:23:20.06 |
-72:49:06.6 |
HIP 115757 |
17.19 |
| 2026-06-04 00:00 |
23:23:21.16 |
-72:49:47.9 |
HIP 115757 |
16.97 |
| 2026-06-04 12:00 |
23:23:22.20 |
-72:50:29.3 |
HIP 115757 |
16.77 |
| 2026-06-05 00:00 |
23:23:23.15 |
-72:51:10.9 |
HIP 115757 |
16.61 |
| 2026-06-05 12:00 |
23:23:24.03 |
-72:51:52.5 |
HIP 115757 |
16.48 |
| 2026-06-06 00:00 |
23:23:24.83 |
-72:52:34.2 |
HIP 115757 |
16.39 |
| 2026-06-06 12:00 |
23:23:25.56 |
-72:53:16.0 |
HIP 115757 |
16.33 |
| 2026-06-07 00:00 |
23:23:26.21 |
-72:53:57.8 |
HIP 115757 |
16.31 |
| 2026-06-07 12:00 |
23:23:26.78 |
-72:54:39.8 |
HIP 115757 |
16.32 |
| 2026-06-08 00:00 |
23:23:27.28 |
-72:55:21.8 |
HIP 115757 |
16.37 |
| 2026-06-08 12:00 |
23:23:27.69 |
-72:56:03.9 |
HIP 115757 |
16.46 |
| 2026-06-09 00:00 |
23:23:28.03 |
-72:56:46.1 |
HIP 115757 |
16.58 |
| 2026-06-09 12:00 |
23:23:28.29 |
-72:57:28.4 |
HIP 115757 |
16.73 |
| 2026-06-10 00:00 |
23:23:28.48 |
-72:58:10.7 |
HIP 115757 |
16.92 |
| 2026-06-10 12:00 |
23:23:28.58 |
-72:58:53.1 |
HIP 115757 |
17.14 |
| 2026-06-11 00:00 |
23:23:28.61 |
-72:59:35.5 |
HIP 115757 |
17.40 |
| 2026-06-11 12:00 |
23:23:28.55 |
-73:00:18.0 |
HIP 115605 |
17.59 |
| 2026-06-12 00:00 |
23:23:28.42 |
-73:01:00.6 |
HIP 115605 |
16.95 |
| 2026-06-12 12:00 |
23:23:28.21 |
-73:01:43.2 |
HIP 115605 |
16.31 |
| 2026-06-13 00:00 |
23:23:27.92 |
-73:02:25.9 |
HIP 115605 |
15.68 |
| 2026-06-13 12:00 |
23:23:27.55 |
-73:03:08.6 |
HIP 115605 |
15.06 |
| 2026-06-14 00:00 |
23:23:27.10 |
-73:03:51.4 |
HIP 115605 |
14.45 |
| 2026-06-14 12:00 |
23:23:26.56 |
-73:04:34.2 |
HIP 115605 |
13.86 |
| 2026-06-15 00:00 |
23:23:25.95 |
-73:05:17.0 |
HIP 115605 |
13.27 |
| 2026-06-15 12:00 |
23:23:25.26 |
-73:05:59.9 |
HIP 115605 |
12.71 |
| 2026-06-16 00:00 |
23:23:24.49 |
-73:06:42.8 |
HIP 115605 |
12.16 |
| 2026-06-16 12:00 |
23:23:23.64 |
-73:07:25.7 |
HIP 115605 |
11.64 |
| 2026-06-17 00:00 |
23:23:22.70 |
-73:08:08.6 |
HIP 115605 |
11.14 |
| 2026-06-17 12:00 |
23:23:21.69 |
-73:08:51.6 |
HIP 115605 |
10.66 |
| 2026-06-18 00:00 |
23:23:20.59 |
-73:09:34.6 |
HIP 115605 |
10.23 |
| 2026-06-18 12:00 |
23:23:19.42 |
-73:10:17.6 |
HIP 115605 |
9.83 |
| 2026-06-19 00:00 |
23:23:18.16 |
-73:11:00.6 |
HIP 115605 |
9.47 |
| 2026-06-19 12:00 |
23:23:16.82 |
-73:11:43.6 |
HIP 115605 |
9.16 |
| 2026-06-20 00:00 |
23:23:15.40 |
-73:12:26.6 |
HIP 115605 |
8.90 |
| 2026-06-20 12:00 |
23:23:13.90 |
-73:13:09.6 |
HIP 115605 |
8.70 |
| 2026-06-21 00:00 |
23:23:12.32 |
-73:13:52.6 |
HIP 115605 |
8.57 |
| 2026-06-21 12:00 |
23:23:10.66 |
-73:14:35.6 |
HIP 115605 |
8.50 |
| 2026-06-22 00:00 |
23:23:08.92 |
-73:15:18.6 |
HIP 115605 |
8.49 |