| Parameter |
Value |
| Designation |
C/2006 L2 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2006-11-20T04:47:09.041280Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:58Z |
| Obs used |
400 |
| NEO |
- |
| M1 |
10.400 |
| K1 |
7.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2006-09-29.0000000 |
| e |
1.00101694 |
| q (au) |
1.993947 |
| a (au) |
-1960.738221 |
| i (deg) |
101.022296 |
| Ω (om, deg) |
239.245982 |
| ω (w, deg) |
48.034913 |
| M (ma, deg) |
-0.000593 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.163 + 5.317\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.163 |
| n |
5.317 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.977 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2006-06-14 |
2006-10-14 |
+7.4648 |
-3.534 |
| 2006-12-02 |
2007-11-02 |
+6.0663 |
-2.640 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
03:55:41.38 |
-01:55:00.3 |
HIP 18462 |
25.80 |
| 2026-09-20 12:00 |
03:55:40.03 |
-01:55:22.0 |
HIP 18462 |
26.29 |
| 2026-09-21 00:00 |
03:55:38.66 |
-01:55:43.6 |
HIP 18462 |
26.78 |
| 2026-09-21 12:00 |
03:55:37.26 |
-01:56:05.2 |
HIP 18462 |
27.28 |
| 2026-09-22 00:00 |
03:55:35.85 |
-01:56:26.8 |
HIP 18462 |
27.78 |
| 2026-09-22 12:00 |
03:55:34.40 |
-01:56:48.4 |
HIP 18462 |
28.29 |
| 2026-09-23 00:00 |
03:55:32.94 |
-01:57:10.0 |
HIP 18462 |
28.80 |
| 2026-09-23 12:00 |
03:55:31.45 |
-01:57:31.7 |
HIP 18462 |
29.31 |
| 2026-09-24 00:00 |
03:55:29.94 |
-01:57:53.3 |
HIP 18462 |
29.82 |
| 2026-09-24 12:00 |
03:55:28.41 |
-01:58:14.9 |
HIP 18462 |
30.34 |
| 2026-09-25 00:00 |
03:55:26.86 |
-01:58:36.5 |
HIP 18462 |
30.87 |
| 2026-09-25 12:00 |
03:55:25.28 |
-01:58:58.1 |
HIP 18462 |
31.39 |
| 2026-09-26 00:00 |
03:55:23.68 |
-01:59:19.7 |
HIP 18462 |
31.92 |
| 2026-09-26 12:00 |
03:55:22.06 |
-01:59:41.3 |
HIP 18462 |
32.46 |
| 2026-09-27 00:00 |
03:55:20.42 |
-02:00:02.8 |
HIP 18171 |
32.18 |
| 2026-09-27 12:00 |
03:55:18.76 |
-02:00:24.4 |
HIP 18171 |
31.76 |
| 2026-09-28 00:00 |
03:55:17.07 |
-02:00:45.9 |
HIP 18171 |
31.35 |
| 2026-09-28 12:00 |
03:55:15.36 |
-02:01:07.5 |
HIP 18171 |
30.94 |
| 2026-09-29 00:00 |
03:55:13.63 |
-02:01:29.0 |
HIP 18171 |
30.52 |
| 2026-09-29 12:00 |
03:55:11.88 |
-02:01:50.5 |
HIP 18171 |
30.11 |
| 2026-09-30 00:00 |
03:55:10.11 |
-02:02:12.0 |
HIP 18171 |
29.69 |
| 2026-09-30 12:00 |
03:55:08.32 |
-02:02:33.4 |
HIP 18171 |
29.27 |
| 2026-10-01 00:00 |
03:55:06.51 |
-02:02:54.9 |
HIP 18171 |
28.86 |
| 2026-10-01 12:00 |
03:55:04.67 |
-02:03:16.3 |
HIP 18171 |
28.44 |
| 2026-10-02 00:00 |
03:55:02.82 |
-02:03:37.6 |
HIP 18171 |
28.03 |
| 2026-10-02 12:00 |
03:55:00.94 |
-02:03:59.0 |
HIP 18171 |
27.62 |
| 2026-10-03 00:00 |
03:54:59.04 |
-02:04:20.3 |
HIP 18171 |
27.20 |
| 2026-10-03 12:00 |
03:54:57.12 |
-02:04:41.6 |
HIP 18171 |
26.79 |
| 2026-10-04 00:00 |
03:54:55.19 |
-02:05:02.9 |
HIP 18171 |
26.38 |
| 2026-10-04 12:00 |
03:54:53.23 |
-02:05:24.1 |
HIP 18171 |
25.98 |
| 2026-10-05 00:00 |
03:54:51.25 |
-02:05:45.4 |
HIP 18171 |
25.57 |
| 2026-10-05 12:00 |
03:54:49.25 |
-02:06:06.5 |
HIP 18171 |
25.17 |
| 2026-10-06 00:00 |
03:54:47.23 |
-02:06:27.6 |
HIP 18171 |
24.78 |
| 2026-10-06 12:00 |
03:54:45.19 |
-02:06:48.7 |
HIP 18171 |
24.38 |
| 2026-10-07 00:00 |
03:54:43.14 |
-02:07:09.8 |
HIP 18171 |
23.99 |
| 2026-10-07 12:00 |
03:54:41.06 |
-02:07:30.8 |
HIP 18171 |
23.61 |
| 2026-10-08 00:00 |
03:54:38.96 |
-02:07:51.8 |
HIP 18171 |
23.23 |
| 2026-10-08 12:00 |
03:54:36.84 |
-02:08:12.7 |
HIP 18171 |
22.86 |
| 2026-10-09 00:00 |
03:54:34.71 |
-02:08:33.6 |
HIP 18171 |
22.50 |
| 2026-10-09 12:00 |
03:54:32.56 |
-02:08:54.4 |
HIP 18171 |
22.14 |
| 2026-10-10 00:00 |
03:54:30.38 |
-02:09:15.2 |
HIP 18171 |
21.80 |
| 2026-10-10 12:00 |
03:54:28.19 |
-02:09:35.9 |
HIP 18171 |
21.46 |
| 2026-10-11 00:00 |
03:54:25.98 |
-02:09:56.5 |
HIP 18171 |
21.13 |