| Parameter |
Value |
| Designation |
C/2007 M1 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2008-08-11T17:35:21.920640Z |
| Orbit solution date (soln_date, UTC) |
2022-07-06T03:12:21Z |
| Obs used |
232 |
| NEO |
- |
| M1 |
6.600 |
| K1 |
9.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2008-10-11.0000000 |
| e |
0.99520236 |
| q (au) |
7.474661 |
| a (au) |
1557.985505 |
| i (deg) |
139.721499 |
| Ω (om, deg) |
326.808769 |
| ω (w, deg) |
52.635857 |
| M (ma, deg) |
0.000966 |
Magnitude
Scatter + Global Linear
$$
M_a = (4.972 + 4.027\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
4.972 |
| n |
4.027 |
| gf |
1.000 |
| gb |
-1.000 |
| 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) |
| 2026-07-29 00:00 |
10:09:53.78 |
+14:11:18.6 |
HIP 49820 |
8.60 |
| 2026-07-29 12:00 |
10:09:56.44 |
+14:10:58.6 |
HIP 49820 |
7.98 |
| 2026-07-30 00:00 |
10:09:59.11 |
+14:10:38.7 |
HIP 49820 |
7.38 |
| 2026-07-30 12:00 |
10:10:01.80 |
+14:10:18.7 |
HIP 49820 |
6.80 |
| 2026-07-31 00:00 |
10:10:04.49 |
+14:09:58.6 |
HIP 49820 |
6.25 |
| 2026-07-31 12:00 |
10:10:07.19 |
+14:09:38.5 |
HIP 49820 |
5.74 |
| 2026-08-01 00:00 |
10:10:09.90 |
+14:09:18.4 |
HIP 49820 |
5.29 |
| 2026-08-01 12:00 |
10:10:12.62 |
+14:08:58.2 |
HIP 49820 |
4.90 |
| 2026-08-02 00:00 |
10:10:15.35 |
+14:08:38.1 |
HIP 49820 |
4.60 |
| 2026-08-02 12:00 |
10:10:18.10 |
+14:08:17.8 |
HIP 49820 |
4.41 |
| 2026-08-03 00:00 |
10:10:20.85 |
+14:07:57.6 |
HIP 49820 |
4.34 |
| 2026-08-03 12:00 |
10:10:23.60 |
+14:07:37.3 |
HIP 49820 |
4.40 |
| 2026-08-04 00:00 |
10:10:26.37 |
+14:07:17.0 |
HIP 49820 |
4.58 |
| 2026-08-04 12:00 |
10:10:29.15 |
+14:06:56.6 |
HIP 49820 |
4.88 |
| 2026-08-05 00:00 |
10:10:31.93 |
+14:06:36.3 |
HIP 49820 |
5.26 |
| 2026-08-05 12:00 |
10:10:34.72 |
+14:06:15.9 |
HIP 49820 |
5.73 |
| 2026-08-06 00:00 |
10:10:37.53 |
+14:05:55.5 |
HIP 49820 |
6.25 |
| 2026-08-06 12:00 |
10:10:40.33 |
+14:05:35.0 |
HIP 49820 |
6.82 |
| 2026-08-07 00:00 |
10:10:43.15 |
+14:05:14.5 |
HIP 49820 |
7.43 |
| 2026-08-07 12:00 |
10:10:45.97 |
+14:04:54.1 |
HIP 49820 |
8.06 |
| 2026-08-08 00:00 |
10:10:48.80 |
+14:04:33.5 |
HIP 49820 |
8.72 |
| 2026-08-08 12:00 |
10:10:51.64 |
+14:04:13.0 |
HIP 49820 |
9.39 |
| 2026-08-09 00:00 |
10:10:54.49 |
+14:03:52.5 |
HIP 49820 |
10.09 |
| 2026-08-09 12:00 |
10:10:57.34 |
+14:03:31.9 |
HIP 49820 |
10.79 |
| 2026-08-10 00:00 |
10:11:00.19 |
+14:03:11.3 |
HIP 49820 |
11.50 |
| 2026-08-10 12:00 |
10:11:03.06 |
+14:02:50.7 |
HIP 49820 |
12.22 |
| 2026-08-11 00:00 |
10:11:05.93 |
+14:02:30.1 |
HIP 49820 |
12.95 |
| 2026-08-11 12:00 |
10:11:08.80 |
+14:02:09.5 |
HIP 49820 |
13.69 |
| 2026-08-12 00:00 |
10:11:11.68 |
+14:01:48.9 |
HIP 49820 |
14.43 |
| 2026-08-12 12:00 |
10:11:14.57 |
+14:01:28.3 |
HIP 49820 |
15.18 |
| 2026-08-13 00:00 |
10:11:17.46 |
+14:01:07.6 |
HIP 49820 |
15.93 |
| 2026-08-13 12:00 |
10:11:20.35 |
+14:00:47.0 |
HIP 49820 |
16.68 |
| 2026-08-14 00:00 |
10:11:23.25 |
+14:00:26.3 |
HIP 49820 |
17.44 |
| 2026-08-14 12:00 |
10:11:26.16 |
+14:00:05.7 |
HIP 49820 |
18.21 |
| 2026-08-15 00:00 |
10:11:29.06 |
+13:59:45.0 |
HIP 49820 |
18.97 |
| 2026-08-15 12:00 |
10:11:31.97 |
+13:59:24.3 |
HIP 49820 |
19.74 |
| 2026-08-16 00:00 |
10:11:34.89 |
+13:59:03.7 |
HIP 49820 |
20.51 |
| 2026-08-16 12:00 |
10:11:37.81 |
+13:58:43.0 |
HIP 49820 |
21.28 |
| 2026-08-17 00:00 |
10:11:40.73 |
+13:58:22.4 |
HIP 49820 |
22.05 |
| 2026-08-17 12:00 |
10:11:43.65 |
+13:58:01.7 |
HIP 49820 |
22.82 |
| 2026-08-18 00:00 |
10:11:46.58 |
+13:57:41.1 |
HIP 49820 |
23.60 |
| 2026-08-18 12:00 |
10:11:49.51 |
+13:57:20.4 |
HIP 49820 |
24.38 |
| 2026-08-19 00:00 |
10:11:52.44 |
+13:56:59.8 |
HIP 49820 |
25.16 |