| Parameter |
Value |
| Designation |
P/2005 L1 (McNaught) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2005-12-13T02:11:41.599680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:50Z |
| Obs used |
257 |
| NEO |
- |
| M1 |
10.300 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2005-07-03.0000000 |
| e |
0.20923826 |
| q (au) |
3.142854 |
| a (au) |
3.974464 |
| i (deg) |
7.736935 |
| Ω (om, deg) |
138.329197 |
| ω (w, deg) |
149.558655 |
| M (ma, deg) |
339.713017 |
Magnitude
Scatter + Global Linear
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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 |
08:37:18.24 |
+19:13:50.7 |
HIP 42327 |
7.08 |
| 2026-07-29 12:00 |
08:37:46.56 |
+19:12:28.7 |
HIP 42327 |
3.56 |
| 2026-07-30 00:00 |
08:38:14.87 |
+19:11:06.4 |
HIP 42327 |
8.26 |
| 2026-07-30 12:00 |
08:38:43.18 |
+19:09:43.9 |
HIP 42327 |
14.73 |
| 2026-07-31 00:00 |
08:39:11.49 |
+19:08:21.1 |
HIP 42542 |
20.52 |
| 2026-07-31 12:00 |
08:39:39.79 |
+19:06:58.1 |
HIP 42542 |
16.91 |
| 2026-08-01 00:00 |
08:40:08.09 |
+19:05:34.8 |
HIP 42542 |
15.62 |
| 2026-08-01 12:00 |
08:40:36.38 |
+19:04:11.3 |
HIP 42542 |
17.19 |
| 2026-08-02 00:00 |
08:41:04.66 |
+19:02:47.5 |
HIP 42705 |
17.03 |
| 2026-08-02 12:00 |
08:41:32.94 |
+19:01:23.5 |
HIP 42705 |
10.42 |
| 2026-08-03 00:00 |
08:42:01.21 |
+18:59:59.3 |
HIP 42705 |
4.54 |
| 2026-08-03 12:00 |
08:42:29.47 |
+18:58:34.8 |
HIP 42705 |
5.08 |
| 2026-08-04 00:00 |
08:42:57.73 |
+18:57:10.1 |
HIP 42705 |
11.14 |
| 2026-08-04 12:00 |
08:43:25.97 |
+18:55:45.2 |
HIP 42853 |
9.52 |
| 2026-08-05 00:00 |
08:43:54.21 |
+18:54:20.1 |
HIP 42853 |
7.73 |
| 2026-08-05 12:00 |
08:44:22.43 |
+18:52:54.7 |
HIP 42853 |
11.05 |
| 2026-08-06 00:00 |
08:44:50.65 |
+18:51:29.1 |
HIP 42952 |
7.15 |
| 2026-08-06 12:00 |
08:45:18.85 |
+18:50:03.3 |
HIP 42952 |
2.50 |
| 2026-08-07 00:00 |
08:45:47.04 |
+18:48:37.3 |
HIP 42970 |
4.14 |
| 2026-08-07 12:00 |
08:46:15.22 |
+18:47:11.1 |
HIP 43086 |
4.54 |
| 2026-08-08 00:00 |
08:46:43.38 |
+18:45:44.7 |
HIP 43086 |
2.39 |
| 2026-08-08 12:00 |
08:47:11.54 |
+18:44:18.1 |
HIP 43086 |
9.15 |
| 2026-08-09 00:00 |
08:47:39.67 |
+18:42:51.3 |
HIP 43199 |
5.68 |
| 2026-08-09 12:00 |
08:48:07.80 |
+18:41:24.3 |
HIP 43199 |
1.63 |
| 2026-08-10 00:00 |
08:48:35.90 |
+18:39:57.1 |
HIP 43223 |
6.56 |
| 2026-08-10 12:00 |
08:49:03.99 |
+18:38:29.7 |
HIP 43223 |
12.69 |
| 2026-08-11 00:00 |
08:49:32.07 |
+18:37:02.2 |
HIP 43223 |
19.28 |
| 2026-08-11 12:00 |
08:50:00.12 |
+18:35:34.5 |
HIP 43427 |
17.88 |
| 2026-08-12 00:00 |
08:50:28.16 |
+18:34:06.6 |
HIP 43427 |
16.33 |
| 2026-08-12 12:00 |
08:50:56.18 |
+18:32:38.5 |
HIP 43427 |
17.49 |
| 2026-08-13 00:00 |
08:51:24.18 |
+18:31:10.3 |
HIP 43427 |
20.92 |
| 2026-08-13 12:00 |
08:51:52.15 |
+18:29:41.9 |
HIP 43510 |
22.27 |
| 2026-08-14 00:00 |
08:52:20.11 |
+18:28:13.4 |
HIP 43510 |
22.39 |
| 2026-08-14 12:00 |
08:52:48.04 |
+18:26:44.7 |
HIP 43510 |
24.47 |
| 2026-08-15 00:00 |
08:53:15.95 |
+18:25:15.9 |
HIP 43510 |
28.08 |
| 2026-08-15 12:00 |
08:53:43.84 |
+18:23:47.0 |
HIP 43510 |
32.71 |
| 2026-08-16 00:00 |
08:54:11.70 |
+18:22:17.9 |
HIP 43510 |
37.99 |
| 2026-08-16 12:00 |
08:54:39.54 |
+18:20:48.7 |
HIP 43510 |
43.68 |
| 2026-08-17 00:00 |
08:55:07.35 |
+18:19:19.3 |
HIP 43846 |
40.74 |
| 2026-08-17 12:00 |
08:55:35.14 |
+18:17:49.9 |
HIP 43846 |
38.11 |
| 2026-08-18 00:00 |
08:56:02.90 |
+18:16:20.3 |
HIP 44056 |
32.21 |
| 2026-08-18 12:00 |
08:56:30.63 |
+18:14:50.6 |
HIP 44056 |
25.82 |
| 2026-08-19 00:00 |
08:56:58.34 |
+18:13:20.8 |
HIP 44056 |
19.67 |