| Parameter |
Value |
| Designation |
C/2011 N2 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2011-10-18T17:49:39.725760Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:53Z |
| Obs used |
46 |
| NEO |
- |
| M1 |
7.100 |
| K1 |
21.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-07-25.0000000 |
| e |
0.99970333 |
| q (au) |
2.563360 |
| a (au) |
8640.435892 |
| i (deg) |
33.675025 |
| Ω (om, deg) |
274.019032 |
| ω (w, deg) |
357.041413 |
| M (ma, deg) |
359.999895 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.856 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.856 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.747 |
| k |
1.000 |
| 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) |
| 2026-07-29 00:00 |
03:52:39.25 |
+39:24:35.4 |
HIP 18074 |
22.13 |
| 2026-07-29 12:00 |
03:52:41.44 |
+39:24:55.1 |
HIP 18074 |
22.02 |
| 2026-07-30 00:00 |
03:52:43.60 |
+39:25:14.8 |
HIP 18074 |
21.92 |
| 2026-07-30 12:00 |
03:52:45.72 |
+39:25:34.6 |
HIP 18074 |
21.82 |
| 2026-07-31 00:00 |
03:52:47.81 |
+39:25:54.3 |
HIP 18074 |
21.74 |
| 2026-07-31 12:00 |
03:52:49.86 |
+39:26:13.9 |
HIP 18074 |
21.67 |
| 2026-08-01 00:00 |
03:52:51.88 |
+39:26:33.6 |
HIP 18074 |
21.60 |
| 2026-08-01 12:00 |
03:52:53.86 |
+39:26:53.2 |
HIP 18074 |
21.54 |
| 2026-08-02 00:00 |
03:52:55.81 |
+39:27:12.8 |
HIP 18074 |
21.49 |
| 2026-08-02 12:00 |
03:52:57.72 |
+39:27:32.4 |
HIP 18074 |
21.45 |
| 2026-08-03 00:00 |
03:52:59.59 |
+39:27:51.9 |
HIP 18074 |
21.42 |
| 2026-08-03 12:00 |
03:53:01.43 |
+39:28:11.5 |
HIP 18074 |
21.39 |
| 2026-08-04 00:00 |
03:53:03.24 |
+39:28:31.0 |
HIP 18074 |
21.37 |
| 2026-08-04 12:00 |
03:53:05.01 |
+39:28:50.4 |
HIP 18074 |
21.35 |
| 2026-08-05 00:00 |
03:53:06.74 |
+39:29:09.9 |
HIP 18074 |
21.34 |
| 2026-08-05 12:00 |
03:53:08.43 |
+39:29:29.3 |
HIP 18074 |
21.34 |
| 2026-08-06 00:00 |
03:53:10.09 |
+39:29:48.6 |
HIP 18074 |
21.34 |
| 2026-08-06 12:00 |
03:53:11.71 |
+39:30:07.9 |
HIP 18074 |
21.35 |
| 2026-08-07 00:00 |
03:53:13.30 |
+39:30:27.2 |
HIP 18074 |
21.36 |
| 2026-08-07 12:00 |
03:53:14.85 |
+39:30:46.5 |
HIP 18074 |
21.37 |
| 2026-08-08 00:00 |
03:53:16.36 |
+39:31:05.7 |
HIP 18074 |
21.39 |
| 2026-08-08 12:00 |
03:53:17.83 |
+39:31:24.9 |
HIP 18074 |
21.42 |
| 2026-08-09 00:00 |
03:53:19.27 |
+39:31:44.0 |
HIP 18074 |
21.44 |
| 2026-08-09 12:00 |
03:53:20.67 |
+39:32:03.1 |
HIP 18074 |
21.47 |
| 2026-08-10 00:00 |
03:53:22.03 |
+39:32:22.1 |
HIP 18074 |
21.50 |
| 2026-08-10 12:00 |
03:53:23.35 |
+39:32:41.1 |
HIP 18074 |
21.53 |
| 2026-08-11 00:00 |
03:53:24.64 |
+39:33:00.0 |
HIP 18074 |
21.57 |
| 2026-08-11 12:00 |
03:53:25.88 |
+39:33:18.9 |
HIP 18074 |
21.60 |
| 2026-08-12 00:00 |
03:53:27.09 |
+39:33:37.7 |
HIP 18074 |
21.64 |
| 2026-08-12 12:00 |
03:53:28.26 |
+39:33:56.5 |
HIP 18074 |
21.68 |
| 2026-08-13 00:00 |
03:53:29.39 |
+39:34:15.2 |
HIP 18074 |
21.72 |
| 2026-08-13 12:00 |
03:53:30.49 |
+39:34:33.9 |
HIP 18074 |
21.76 |
| 2026-08-14 00:00 |
03:53:31.54 |
+39:34:52.5 |
HIP 18090 |
21.77 |
| 2026-08-14 12:00 |
03:53:32.55 |
+39:35:11.0 |
HIP 18090 |
21.75 |
| 2026-08-15 00:00 |
03:53:33.53 |
+39:35:29.5 |
HIP 18090 |
21.73 |
| 2026-08-15 12:00 |
03:53:34.47 |
+39:35:48.0 |
HIP 18090 |
21.70 |
| 2026-08-16 00:00 |
03:53:35.37 |
+39:36:06.3 |
HIP 18090 |
21.68 |
| 2026-08-16 12:00 |
03:53:36.23 |
+39:36:24.6 |
HIP 18313 |
21.56 |
| 2026-08-17 00:00 |
03:53:37.05 |
+39:36:42.9 |
HIP 18313 |
21.23 |
| 2026-08-17 12:00 |
03:53:37.83 |
+39:37:01.0 |
HIP 18313 |
20.92 |
| 2026-08-18 00:00 |
03:53:38.57 |
+39:37:19.1 |
HIP 18313 |
20.60 |
| 2026-08-18 12:00 |
03:53:39.27 |
+39:37:37.1 |
HIP 18313 |
20.30 |
| 2026-08-19 00:00 |
03:53:39.93 |
+39:37:55.1 |
HIP 18313 |
20.00 |