| 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) |
| 2026-05-12 00:00 |
08:33:49.44 |
+19:20:56.3 |
HIP 42133 |
25.68 |
| 2026-05-12 12:00 |
08:33:50.35 |
+19:20:49.0 |
HIP 42133 |
25.57 |
| 2026-05-13 00:00 |
08:33:51.29 |
+19:20:41.6 |
HIP 42133 |
25.47 |
| 2026-05-13 12:00 |
08:33:52.25 |
+19:20:34.1 |
HIP 42133 |
25.35 |
| 2026-05-14 00:00 |
08:33:53.25 |
+19:20:26.4 |
HIP 42133 |
25.24 |
| 2026-05-14 12:00 |
08:33:54.27 |
+19:20:18.7 |
HIP 42133 |
25.12 |
| 2026-05-15 00:00 |
08:33:55.33 |
+19:20:10.9 |
HIP 42133 |
25.00 |
| 2026-05-15 12:00 |
08:33:56.42 |
+19:20:02.9 |
HIP 42133 |
24.88 |
| 2026-05-16 00:00 |
08:33:57.53 |
+19:19:54.9 |
HIP 42133 |
24.76 |
| 2026-05-16 12:00 |
08:33:58.68 |
+19:19:46.7 |
HIP 42133 |
24.63 |
| 2026-05-17 00:00 |
08:33:59.85 |
+19:19:38.5 |
HIP 42133 |
24.51 |
| 2026-05-17 12:00 |
08:34:01.05 |
+19:19:30.1 |
HIP 42133 |
24.38 |
| 2026-05-18 00:00 |
08:34:02.29 |
+19:19:21.6 |
HIP 42133 |
24.26 |
| 2026-05-18 12:00 |
08:34:03.55 |
+19:19:13.1 |
HIP 42133 |
24.13 |
| 2026-05-19 00:00 |
08:34:04.84 |
+19:19:04.4 |
HIP 42133 |
24.00 |
| 2026-05-19 12:00 |
08:34:06.16 |
+19:18:55.6 |
HIP 42133 |
23.88 |
| 2026-05-20 00:00 |
08:34:07.51 |
+19:18:46.8 |
HIP 42133 |
23.75 |
| 2026-05-20 12:00 |
08:34:08.88 |
+19:18:37.8 |
HIP 42133 |
23.63 |
| 2026-05-21 00:00 |
08:34:10.29 |
+19:18:28.8 |
HIP 42133 |
23.50 |
| 2026-05-21 12:00 |
08:34:11.72 |
+19:18:19.6 |
HIP 42133 |
23.38 |
| 2026-05-22 00:00 |
08:34:13.18 |
+19:18:10.3 |
HIP 42133 |
23.26 |
| 2026-05-22 12:00 |
08:34:14.66 |
+19:18:01.0 |
HIP 42133 |
23.15 |
| 2026-05-23 00:00 |
08:34:16.18 |
+19:17:51.5 |
HIP 42133 |
23.03 |
| 2026-05-23 12:00 |
08:34:17.72 |
+19:17:42.0 |
HIP 42133 |
22.92 |
| 2026-05-24 00:00 |
08:34:19.29 |
+19:17:32.3 |
HIP 42133 |
22.81 |
| 2026-05-24 12:00 |
08:34:20.89 |
+19:17:22.6 |
HIP 42133 |
22.71 |
| 2026-05-25 00:00 |
08:34:22.51 |
+19:17:12.8 |
HIP 42133 |
22.61 |
| 2026-05-25 12:00 |
08:34:24.16 |
+19:17:02.8 |
HIP 42133 |
22.52 |
| 2026-05-26 00:00 |
08:34:25.84 |
+19:16:52.8 |
HIP 42133 |
22.43 |
| 2026-05-26 12:00 |
08:34:27.55 |
+19:16:42.7 |
HIP 42133 |
22.34 |
| 2026-05-27 00:00 |
08:34:29.28 |
+19:16:32.5 |
HIP 42133 |
22.27 |
| 2026-05-27 12:00 |
08:34:31.03 |
+19:16:22.2 |
HIP 42133 |
22.20 |
| 2026-05-28 00:00 |
08:34:32.81 |
+19:16:11.8 |
HIP 42133 |
22.13 |
| 2026-05-28 12:00 |
08:34:34.62 |
+19:16:01.4 |
HIP 42133 |
22.08 |
| 2026-05-29 00:00 |
08:34:36.45 |
+19:15:50.8 |
HIP 42133 |
22.03 |
| 2026-05-29 12:00 |
08:34:38.31 |
+19:15:40.1 |
HIP 42133 |
21.99 |
| 2026-05-30 00:00 |
08:34:40.20 |
+19:15:29.4 |
HIP 42133 |
21.96 |
| 2026-05-30 12:00 |
08:34:42.11 |
+19:15:18.6 |
HIP 42133 |
21.94 |
| 2026-05-31 00:00 |
08:34:44.04 |
+19:15:07.6 |
HIP 42133 |
21.93 |
| 2026-05-31 12:00 |
08:34:46.00 |
+19:14:56.6 |
HIP 42133 |
21.93 |
| 2026-06-01 00:00 |
08:34:47.99 |
+19:14:45.5 |
HIP 42133 |
21.94 |
| 2026-06-01 12:00 |
08:34:50.00 |
+19:14:34.4 |
HIP 42133 |
21.96 |
| 2026-06-02 00:00 |
08:34:52.03 |
+19:14:23.1 |
HIP 42133 |
21.99 |