C/2005 L2 (McNaught)
| Parameter |
Value |
| Designation |
C/2005 L2 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2005-07-14T12:31:58.244160Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:50Z |
| Obs used |
54 |
| NEO |
- |
| M1 |
14.400 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2005-09-03.0000000 |
| e |
0.99997944 |
| q (au) |
3.193792 |
| a (au) |
155353.269479 |
| i (deg) |
152.764081 |
| Ω (om, deg) |
155.872566 |
| ω (w, deg) |
294.238895 |
| M (ma, deg) |
0.000001 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.989 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.989 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.770 |
| 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) |
| 2026-02-03 00:00 |
04:34:18.51 |
+49:30:54.0 |
HIP 21345 |
7.65 |
| 2026-02-03 12:00 |
04:34:16.12 |
+49:30:31.8 |
HIP 21345 |
8.19 |
| 2026-02-04 00:00 |
04:34:13.77 |
+49:30:09.6 |
HIP 21345 |
8.71 |
| 2026-02-04 12:00 |
04:34:11.46 |
+49:29:47.4 |
HIP 21345 |
9.24 |
| 2026-02-05 00:00 |
04:34:09.18 |
+49:29:25.2 |
HIP 21345 |
9.76 |
| 2026-02-05 12:00 |
04:34:06.95 |
+49:29:03.0 |
HIP 21345 |
10.28 |
| 2026-02-06 00:00 |
04:34:04.75 |
+49:28:40.7 |
HIP 21345 |
10.80 |
| 2026-02-06 12:00 |
04:34:02.59 |
+49:28:18.4 |
HIP 21345 |
11.31 |
| 2026-02-07 00:00 |
04:34:00.47 |
+49:27:56.1 |
HIP 21345 |
11.81 |
| 2026-02-07 12:00 |
04:33:58.40 |
+49:27:33.8 |
HIP 21345 |
12.32 |
| 2026-02-08 00:00 |
04:33:56.36 |
+49:27:11.4 |
HIP 21345 |
12.81 |
| 2026-02-08 12:00 |
04:33:54.36 |
+49:26:49.1 |
HIP 21345 |
13.31 |
| 2026-02-09 00:00 |
04:33:52.39 |
+49:26:26.7 |
HIP 21345 |
13.80 |
| 2026-02-09 12:00 |
04:33:50.47 |
+49:26:04.4 |
HIP 21345 |
14.29 |
| 2026-02-10 00:00 |
04:33:48.59 |
+49:25:42.0 |
HIP 21345 |
14.77 |
| 2026-02-10 12:00 |
04:33:46.75 |
+49:25:19.6 |
HIP 21345 |
15.24 |
| 2026-02-11 00:00 |
04:33:44.95 |
+49:24:57.2 |
HIP 21345 |
15.72 |
| 2026-02-11 12:00 |
04:33:43.19 |
+49:24:34.9 |
HIP 21345 |
16.19 |
| 2026-02-12 00:00 |
04:33:41.47 |
+49:24:12.5 |
HIP 21345 |
16.65 |
| 2026-02-12 12:00 |
04:33:39.79 |
+49:23:50.1 |
HIP 21345 |
17.11 |
| 2026-02-13 00:00 |
04:33:38.15 |
+49:23:27.8 |
HIP 21345 |
17.57 |
| 2026-02-13 12:00 |
04:33:36.54 |
+49:23:05.4 |
HIP 21345 |
18.02 |
| 2026-02-14 00:00 |
04:33:34.98 |
+49:22:43.0 |
HIP 21345 |
18.47 |
| 2026-02-14 12:00 |
04:33:33.47 |
+49:22:20.7 |
HIP 21345 |
18.91 |
| 2026-02-15 00:00 |
04:33:31.99 |
+49:21:58.4 |
HIP 21345 |
19.35 |
| 2026-02-15 12:00 |
04:33:30.55 |
+49:21:36.1 |
HIP 21345 |
19.79 |
| 2026-02-16 00:00 |
04:33:29.15 |
+49:21:13.8 |
HIP 21345 |
20.22 |
| 2026-02-16 12:00 |
04:33:27.79 |
+49:20:51.5 |
HIP 21345 |
20.64 |
| 2026-02-17 00:00 |
04:33:26.48 |
+49:20:29.2 |
HIP 21345 |
21.07 |
| 2026-02-17 12:00 |
04:33:25.20 |
+49:20:07.0 |
HIP 21345 |
21.48 |
| 2026-02-18 00:00 |
04:33:23.97 |
+49:19:44.8 |
HIP 21345 |
21.90 |
| 2026-02-18 12:00 |
04:33:22.77 |
+49:19:22.6 |
HIP 21345 |
22.31 |
| 2026-02-19 00:00 |
04:33:21.62 |
+49:19:00.4 |
HIP 21345 |
22.71 |
| 2026-02-19 12:00 |
04:33:20.51 |
+49:18:38.3 |
HIP 21345 |
23.11 |
| 2026-02-20 00:00 |
04:33:19.44 |
+49:18:16.2 |
HIP 21345 |
23.51 |
| 2026-02-20 12:00 |
04:33:18.41 |
+49:17:54.1 |
HIP 21345 |
23.90 |
| 2026-02-21 00:00 |
04:33:17.42 |
+49:17:32.1 |
HIP 21345 |
24.29 |
| 2026-02-21 12:00 |
04:33:16.47 |
+49:17:10.1 |
HIP 21345 |
24.68 |
| 2026-02-22 00:00 |
04:33:15.56 |
+49:16:48.2 |
HIP 21345 |
25.06 |
| 2026-02-22 12:00 |
04:33:14.69 |
+49:16:26.3 |
HIP 21345 |
25.43 |
| 2026-02-23 00:00 |
04:33:13.87 |
+49:16:04.4 |
HIP 21345 |
25.80 |
| 2026-02-23 12:00 |
04:33:13.08 |
+49:15:42.6 |
HIP 21345 |
26.17 |
| 2026-02-24 00:00 |
04:33:12.34 |
+49:15:20.8 |
HIP 21345 |
26.54 |