| 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) |
| 2026-05-12 00:00 |
07:30:06.88 |
+21:30:51.8 |
HIP 36307 |
23.83 |
| 2026-05-12 12:00 |
07:30:27.18 |
+21:30:33.7 |
HIP 36307 |
28.56 |
| 2026-05-13 00:00 |
07:30:47.61 |
+21:30:15.1 |
HIP 36663 |
25.54 |
| 2026-05-13 12:00 |
07:31:08.15 |
+21:29:56.0 |
HIP 36663 |
20.83 |
| 2026-05-14 00:00 |
07:31:28.80 |
+21:29:36.4 |
HIP 36663 |
16.13 |
| 2026-05-14 12:00 |
07:31:49.58 |
+21:29:16.3 |
HIP 36663 |
11.51 |
| 2026-05-15 00:00 |
07:32:10.46 |
+21:28:55.7 |
HIP 36663 |
7.16 |
| 2026-05-15 12:00 |
07:32:31.46 |
+21:28:34.7 |
HIP 36663 |
4.17 |
| 2026-05-16 00:00 |
07:32:52.57 |
+21:28:13.2 |
HIP 36663 |
5.63 |
| 2026-05-16 12:00 |
07:33:13.80 |
+21:27:51.2 |
HIP 36663 |
9.74 |
| 2026-05-17 00:00 |
07:33:35.13 |
+21:27:28.7 |
HIP 36663 |
14.42 |
| 2026-05-17 12:00 |
07:33:56.57 |
+21:27:05.7 |
HIP 36663 |
19.27 |
| 2026-05-18 00:00 |
07:34:18.12 |
+21:26:42.3 |
HIP 36789 |
19.72 |
| 2026-05-18 12:00 |
07:34:39.77 |
+21:26:18.4 |
HIP 36789 |
20.99 |
| 2026-05-19 00:00 |
07:35:01.53 |
+21:25:53.9 |
HIP 36789 |
23.33 |
| 2026-05-19 12:00 |
07:35:23.40 |
+21:25:29.1 |
HIP 37084 |
25.84 |
| 2026-05-20 00:00 |
07:35:45.37 |
+21:25:03.7 |
HIP 37084 |
20.72 |
| 2026-05-20 12:00 |
07:36:07.44 |
+21:24:37.9 |
HIP 37084 |
15.57 |
| 2026-05-21 00:00 |
07:36:29.61 |
+21:24:11.5 |
HIP 37084 |
10.41 |
| 2026-05-21 12:00 |
07:36:51.88 |
+21:23:44.7 |
HIP 37084 |
5.24 |
| 2026-05-22 00:00 |
07:37:14.25 |
+21:23:17.5 |
HIP 37084 |
0.92 |
| 2026-05-22 12:00 |
07:37:36.72 |
+21:22:49.7 |
HIP 37084 |
5.39 |
| 2026-05-23 00:00 |
07:37:59.28 |
+21:22:21.5 |
HIP 37084 |
10.63 |
| 2026-05-23 12:00 |
07:38:21.94 |
+21:21:52.8 |
HIP 37084 |
15.91 |
| 2026-05-24 00:00 |
07:38:44.69 |
+21:21:23.6 |
HIP 37214 |
18.60 |
| 2026-05-24 12:00 |
07:39:07.54 |
+21:20:54.0 |
HIP 37214 |
20.14 |
| 2026-05-25 00:00 |
07:39:30.48 |
+21:20:23.9 |
HIP 37214 |
22.87 |
| 2026-05-25 12:00 |
07:39:53.51 |
+21:19:53.3 |
HIP 37442 |
19.69 |
| 2026-05-26 00:00 |
07:40:16.64 |
+21:19:22.2 |
HIP 37442 |
15.03 |
| 2026-05-26 12:00 |
07:40:39.85 |
+21:18:50.7 |
HIP 37442 |
11.05 |
| 2026-05-27 00:00 |
07:41:03.15 |
+21:18:18.7 |
HIP 37442 |
8.79 |
| 2026-05-27 12:00 |
07:41:26.54 |
+21:17:46.2 |
HIP 37442 |
9.61 |
| 2026-05-28 00:00 |
07:41:50.01 |
+21:17:13.3 |
HIP 37442 |
12.95 |
| 2026-05-28 12:00 |
07:42:13.58 |
+21:16:39.9 |
HIP 37442 |
17.44 |
| 2026-05-29 00:00 |
07:42:37.22 |
+21:16:06.0 |
HIP 37540 |
18.23 |
| 2026-05-29 12:00 |
07:43:00.95 |
+21:15:31.7 |
HIP 37540 |
19.98 |
| 2026-05-30 00:00 |
07:43:24.77 |
+21:14:56.9 |
HIP 37540 |
22.99 |
| 2026-05-30 12:00 |
07:43:48.66 |
+21:14:21.6 |
HIP 37540 |
26.85 |
| 2026-05-31 00:00 |
07:44:12.64 |
+21:13:45.9 |
HIP 37909 |
27.64 |
| 2026-05-31 12:00 |
07:44:36.70 |
+21:13:09.7 |
HIP 37909 |
22.06 |
| 2026-06-01 00:00 |
07:45:00.84 |
+21:12:33.1 |
HIP 37909 |
16.49 |
| 2026-06-01 12:00 |
07:45:25.06 |
+21:11:55.9 |
HIP 37909 |
11.01 |
| 2026-06-02 00:00 |
07:45:49.35 |
+21:11:18.3 |
HIP 37909 |
5.89 |