| 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) |
| 2026-07-29 00:00 |
23:17:20.93 |
-74:04:12.1 |
HIP 114857 |
13.11 |
| 2026-07-29 12:00 |
23:17:13.47 |
-74:04:45.4 |
HIP 114857 |
13.38 |
| 2026-07-30 00:00 |
23:17:05.95 |
-74:05:18.4 |
HIP 114857 |
13.69 |
| 2026-07-30 12:00 |
23:16:58.37 |
-74:05:51.2 |
HIP 114857 |
14.03 |
| 2026-07-31 00:00 |
23:16:50.72 |
-74:06:23.8 |
HIP 114857 |
14.39 |
| 2026-07-31 12:00 |
23:16:43.01 |
-74:06:56.1 |
HIP 114857 |
14.78 |
| 2026-08-01 00:00 |
23:16:35.24 |
-74:07:28.1 |
HIP 114857 |
15.19 |
| 2026-08-01 12:00 |
23:16:27.41 |
-74:08:00.0 |
HIP 114857 |
15.62 |
| 2026-08-02 00:00 |
23:16:19.52 |
-74:08:31.4 |
HIP 114857 |
16.07 |
| 2026-08-02 12:00 |
23:16:11.57 |
-74:09:02.7 |
HIP 114857 |
16.54 |
| 2026-08-03 00:00 |
23:16:03.56 |
-74:09:33.7 |
HIP 114857 |
17.02 |
| 2026-08-03 12:00 |
23:15:55.49 |
-74:10:04.5 |
HIP 114857 |
17.52 |
| 2026-08-04 00:00 |
23:15:47.36 |
-74:10:34.9 |
HIP 114857 |
18.04 |
| 2026-08-04 12:00 |
23:15:39.17 |
-74:11:05.1 |
HIP 114857 |
18.56 |
| 2026-08-05 00:00 |
23:15:30.92 |
-74:11:35.1 |
HIP 114857 |
19.10 |
| 2026-08-05 12:00 |
23:15:22.62 |
-74:12:04.7 |
HIP 114813 |
19.45 |
| 2026-08-06 00:00 |
23:15:14.26 |
-74:12:34.1 |
HIP 114813 |
18.98 |
| 2026-08-06 12:00 |
23:15:05.85 |
-74:13:03.1 |
HIP 114813 |
18.53 |
| 2026-08-07 00:00 |
23:14:57.38 |
-74:13:31.9 |
HIP 114813 |
18.10 |
| 2026-08-07 12:00 |
23:14:48.86 |
-74:14:00.5 |
HIP 114813 |
17.70 |
| 2026-08-08 00:00 |
23:14:40.28 |
-74:14:28.7 |
HIP 114813 |
17.32 |
| 2026-08-08 12:00 |
23:14:31.65 |
-74:14:56.6 |
HIP 114813 |
16.98 |
| 2026-08-09 00:00 |
23:14:22.96 |
-74:15:24.2 |
HIP 114813 |
16.67 |
| 2026-08-09 12:00 |
23:14:14.23 |
-74:15:51.6 |
HIP 114813 |
16.39 |
| 2026-08-10 00:00 |
23:14:05.44 |
-74:16:18.6 |
HIP 114813 |
16.15 |
| 2026-08-10 12:00 |
23:13:56.61 |
-74:16:45.3 |
HIP 114813 |
15.94 |
| 2026-08-11 00:00 |
23:13:47.72 |
-74:17:11.8 |
HIP 114813 |
15.77 |
| 2026-08-11 12:00 |
23:13:38.78 |
-74:17:37.9 |
HIP 114813 |
15.64 |
| 2026-08-12 00:00 |
23:13:29.80 |
-74:18:03.7 |
HIP 114813 |
15.55 |
| 2026-08-12 12:00 |
23:13:20.77 |
-74:18:29.2 |
HIP 114813 |
15.50 |
| 2026-08-13 00:00 |
23:13:11.69 |
-74:18:54.3 |
HIP 114813 |
15.50 |
| 2026-08-13 12:00 |
23:13:02.57 |
-74:19:19.2 |
HIP 114813 |
15.53 |
| 2026-08-14 00:00 |
23:12:53.40 |
-74:19:43.7 |
HIP 114813 |
15.61 |
| 2026-08-14 12:00 |
23:12:44.19 |
-74:20:07.9 |
HIP 114813 |
15.72 |
| 2026-08-15 00:00 |
23:12:34.93 |
-74:20:31.8 |
HIP 114813 |
15.88 |
| 2026-08-15 12:00 |
23:12:25.63 |
-74:20:55.4 |
HIP 114813 |
16.07 |
| 2026-08-16 00:00 |
23:12:16.30 |
-74:21:18.6 |
HIP 114813 |
16.29 |
| 2026-08-16 12:00 |
23:12:06.91 |
-74:21:41.5 |
HIP 114813 |
16.56 |
| 2026-08-17 00:00 |
23:11:57.49 |
-74:22:04.1 |
HIP 114402 |
16.15 |
| 2026-08-17 12:00 |
23:11:48.03 |
-74:22:26.3 |
HIP 114402 |
15.53 |
| 2026-08-18 00:00 |
23:11:38.54 |
-74:22:48.2 |
HIP 114402 |
14.94 |
| 2026-08-18 12:00 |
23:11:29.00 |
-74:23:09.8 |
HIP 114402 |
14.36 |
| 2026-08-19 00:00 |
23:11:19.43 |
-74:23:31.0 |
HIP 114402 |
13.79 |