| 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 |
-0.999 |
| 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) |
| 2026-05-12 00:00 |
03:42:08.71 |
+38:42:28.0 |
HIP 17279 |
7.16 |
| 2026-05-12 12:00 |
03:42:13.57 |
+38:42:36.4 |
HIP 17279 |
7.30 |
| 2026-05-13 00:00 |
03:42:18.44 |
+38:42:44.9 |
HIP 17279 |
7.56 |
| 2026-05-13 12:00 |
03:42:23.31 |
+38:42:53.6 |
HIP 17279 |
7.92 |
| 2026-05-14 00:00 |
03:42:28.18 |
+38:43:02.5 |
HIP 17279 |
8.38 |
| 2026-05-14 12:00 |
03:42:33.05 |
+38:43:11.5 |
HIP 17279 |
8.91 |
| 2026-05-15 00:00 |
03:42:37.93 |
+38:43:20.6 |
HIP 17279 |
9.51 |
| 2026-05-15 12:00 |
03:42:42.81 |
+38:43:29.9 |
HIP 17279 |
10.17 |
| 2026-05-16 00:00 |
03:42:47.69 |
+38:43:39.4 |
HIP 17279 |
10.87 |
| 2026-05-16 12:00 |
03:42:52.58 |
+38:43:48.9 |
HIP 17279 |
11.61 |
| 2026-05-17 00:00 |
03:42:57.46 |
+38:43:58.7 |
HIP 17279 |
12.38 |
| 2026-05-17 12:00 |
03:43:02.35 |
+38:44:08.5 |
HIP 17279 |
13.17 |
| 2026-05-18 00:00 |
03:43:07.23 |
+38:44:18.5 |
HIP 17279 |
13.99 |
| 2026-05-18 12:00 |
03:43:12.12 |
+38:44:28.7 |
HIP 17279 |
14.82 |
| 2026-05-19 00:00 |
03:43:17.01 |
+38:44:38.9 |
HIP 17279 |
15.66 |
| 2026-05-19 12:00 |
03:43:21.90 |
+38:44:49.4 |
HIP 17279 |
16.52 |
| 2026-05-20 00:00 |
03:43:26.78 |
+38:45:00.0 |
HIP 17279 |
17.39 |
| 2026-05-20 12:00 |
03:43:31.67 |
+38:45:10.6 |
HIP 17279 |
18.27 |
| 2026-05-21 00:00 |
03:43:36.55 |
+38:45:21.4 |
HIP 17279 |
19.16 |
| 2026-05-21 12:00 |
03:43:41.43 |
+38:45:32.4 |
HIP 17279 |
20.05 |
| 2026-05-22 00:00 |
03:43:46.31 |
+38:45:43.5 |
HIP 17279 |
20.95 |
| 2026-05-22 12:00 |
03:43:51.19 |
+38:45:54.7 |
HIP 17558 |
21.34 |
| 2026-05-23 00:00 |
03:43:56.07 |
+38:46:06.1 |
HIP 17558 |
20.47 |
| 2026-05-23 12:00 |
03:44:00.94 |
+38:46:17.6 |
HIP 17558 |
19.61 |
| 2026-05-24 00:00 |
03:44:05.81 |
+38:46:29.2 |
HIP 17558 |
18.76 |
| 2026-05-24 12:00 |
03:44:10.67 |
+38:46:40.9 |
HIP 17558 |
17.93 |
| 2026-05-25 00:00 |
03:44:15.54 |
+38:46:52.8 |
HIP 17558 |
17.11 |
| 2026-05-25 12:00 |
03:44:20.40 |
+38:47:04.8 |
HIP 17558 |
16.32 |
| 2026-05-26 00:00 |
03:44:25.25 |
+38:47:16.9 |
HIP 17558 |
15.54 |
| 2026-05-26 12:00 |
03:44:30.10 |
+38:47:29.2 |
HIP 17558 |
14.78 |
| 2026-05-27 00:00 |
03:44:34.95 |
+38:47:41.5 |
HIP 17558 |
14.06 |
| 2026-05-27 12:00 |
03:44:39.79 |
+38:47:54.0 |
HIP 17558 |
13.37 |
| 2026-05-28 00:00 |
03:44:44.63 |
+38:48:06.7 |
HIP 17558 |
12.71 |
| 2026-05-28 12:00 |
03:44:49.46 |
+38:48:19.4 |
HIP 17558 |
12.10 |
| 2026-05-29 00:00 |
03:44:54.28 |
+38:48:32.3 |
HIP 17558 |
11.54 |
| 2026-05-29 12:00 |
03:44:59.10 |
+38:48:45.2 |
HIP 17558 |
11.04 |
| 2026-05-30 00:00 |
03:45:03.91 |
+38:48:58.3 |
HIP 17558 |
10.60 |
| 2026-05-30 12:00 |
03:45:08.72 |
+38:49:11.5 |
HIP 17558 |
10.24 |
| 2026-05-31 00:00 |
03:45:13.52 |
+38:49:24.9 |
HIP 17558 |
9.97 |
| 2026-05-31 12:00 |
03:45:18.31 |
+38:49:38.3 |
HIP 17558 |
9.78 |
| 2026-06-01 00:00 |
03:45:23.10 |
+38:49:51.9 |
HIP 17558 |
9.69 |
| 2026-06-01 12:00 |
03:45:27.87 |
+38:50:05.6 |
HIP 17558 |
9.69 |
| 2026-06-02 00:00 |
03:45:32.64 |
+38:50:19.4 |
HIP 17558 |
9.79 |