| Parameter |
Value |
| Designation |
C/2011 L3 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2011-08-10T12:00:37.532160Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:51Z |
| Obs used |
798 |
| NEO |
- |
| M1 |
14.700 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-08-05.0000000 |
| e |
1.00010168 |
| q (au) |
1.923846 |
| a (au) |
-18921.284723 |
| i (deg) |
87.114423 |
| Ω (om, deg) |
307.755201 |
| ω (w, deg) |
27.727029 |
| M (ma, deg) |
-0.000002 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.294 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.294 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.528 |
| 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) |
| 2026-09-20 00:00 |
08:46:07.78 |
+18:19:26.8 |
HIP 43044 |
8.71 |
| 2026-09-20 12:00 |
08:46:10.09 |
+18:19:14.7 |
HIP 43044 |
8.47 |
| 2026-09-21 00:00 |
08:46:12.38 |
+18:19:02.6 |
HIP 43044 |
8.26 |
| 2026-09-21 12:00 |
08:46:14.65 |
+18:18:50.7 |
HIP 43044 |
8.09 |
| 2026-09-22 00:00 |
08:46:16.89 |
+18:18:38.9 |
HIP 43044 |
7.96 |
| 2026-09-22 12:00 |
08:46:19.11 |
+18:18:27.1 |
HIP 43044 |
7.86 |
| 2026-09-23 00:00 |
08:46:21.31 |
+18:18:15.4 |
HIP 43044 |
7.81 |
| 2026-09-23 12:00 |
08:46:23.49 |
+18:18:03.8 |
HIP 43044 |
7.79 |
| 2026-09-24 00:00 |
08:46:25.64 |
+18:17:52.4 |
HIP 43044 |
7.82 |
| 2026-09-24 12:00 |
08:46:27.77 |
+18:17:41.0 |
HIP 43044 |
7.88 |
| 2026-09-25 00:00 |
08:46:29.87 |
+18:17:29.6 |
HIP 43044 |
7.97 |
| 2026-09-25 12:00 |
08:46:31.95 |
+18:17:18.4 |
HIP 43044 |
8.10 |
| 2026-09-26 00:00 |
08:46:34.01 |
+18:17:07.3 |
HIP 43044 |
8.25 |
| 2026-09-26 12:00 |
08:46:36.04 |
+18:16:56.3 |
HIP 43044 |
8.43 |
| 2026-09-27 00:00 |
08:46:38.05 |
+18:16:45.3 |
HIP 43044 |
8.64 |
| 2026-09-27 12:00 |
08:46:40.03 |
+18:16:34.5 |
HIP 43044 |
8.87 |
| 2026-09-28 00:00 |
08:46:41.99 |
+18:16:23.8 |
HIP 43044 |
9.11 |
| 2026-09-28 12:00 |
08:46:43.92 |
+18:16:13.1 |
HIP 43044 |
9.37 |
| 2026-09-29 00:00 |
08:46:45.83 |
+18:16:02.6 |
HIP 43044 |
9.65 |
| 2026-09-29 12:00 |
08:46:47.71 |
+18:15:52.1 |
HIP 43044 |
9.94 |
| 2026-09-30 00:00 |
08:46:49.57 |
+18:15:41.8 |
HIP 43044 |
10.24 |
| 2026-09-30 12:00 |
08:46:51.40 |
+18:15:31.5 |
HIP 43044 |
10.54 |
| 2026-10-01 00:00 |
08:46:53.21 |
+18:15:21.3 |
HIP 43044 |
10.85 |
| 2026-10-01 12:00 |
08:46:54.99 |
+18:15:11.3 |
HIP 43044 |
11.17 |
| 2026-10-02 00:00 |
08:46:56.74 |
+18:15:01.3 |
HIP 43044 |
11.49 |
| 2026-10-02 12:00 |
08:46:58.47 |
+18:14:51.5 |
HIP 43044 |
11.82 |
| 2026-10-03 00:00 |
08:47:00.17 |
+18:14:41.7 |
HIP 43044 |
12.15 |
| 2026-10-03 12:00 |
08:47:01.85 |
+18:14:32.1 |
HIP 43044 |
12.47 |
| 2026-10-04 00:00 |
08:47:03.50 |
+18:14:22.5 |
HIP 43044 |
12.80 |
| 2026-10-04 12:00 |
08:47:05.12 |
+18:14:13.1 |
HIP 43044 |
13.13 |
| 2026-10-05 00:00 |
08:47:06.72 |
+18:14:03.7 |
HIP 43044 |
13.46 |
| 2026-10-05 12:00 |
08:47:08.28 |
+18:13:54.5 |
HIP 43044 |
13.78 |
| 2026-10-06 00:00 |
08:47:09.83 |
+18:13:45.4 |
HIP 43044 |
14.11 |
| 2026-10-06 12:00 |
08:47:11.34 |
+18:13:36.3 |
HIP 43044 |
14.43 |
| 2026-10-07 00:00 |
08:47:12.82 |
+18:13:27.4 |
HIP 43044 |
14.75 |
| 2026-10-07 12:00 |
08:47:14.28 |
+18:13:18.6 |
HIP 43044 |
15.06 |
| 2026-10-08 00:00 |
08:47:15.71 |
+18:13:09.9 |
HIP 43044 |
15.38 |
| 2026-10-08 12:00 |
08:47:17.11 |
+18:13:01.3 |
HIP 43044 |
15.68 |
| 2026-10-09 00:00 |
08:47:18.49 |
+18:12:52.9 |
HIP 43044 |
15.99 |
| 2026-10-09 12:00 |
08:47:19.83 |
+18:12:44.5 |
HIP 43044 |
16.29 |
| 2026-10-10 00:00 |
08:47:21.15 |
+18:12:36.2 |
HIP 43044 |
16.58 |
| 2026-10-10 12:00 |
08:47:22.44 |
+18:12:28.1 |
HIP 43044 |
16.87 |
| 2026-10-11 00:00 |
08:47:23.70 |
+18:12:20.1 |
HIP 43044 |
17.16 |