| Parameter |
Value |
| Designation |
C/2012 C1 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-02-04T12:32:23.248320Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:00Z |
| Obs used |
219 |
| NEO |
- |
| M1 |
6.700 |
| K1 |
11.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-11-05.0000000 |
| e |
0.99620583 |
| q (au) |
4.837975 |
| a (au) |
1275.108361 |
| i (deg) |
96.277709 |
| Ω (om, deg) |
300.639926 |
| ω (w, deg) |
279.889151 |
| M (ma, deg) |
359.998019 |
Magnitude
Scatter + Global Linear
$$
M_a = (2.686 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
2.686 |
| n |
6.000 |
| gf |
0.949 |
| gb |
-0.999 |
| k |
1.000 |
| δ90 |
9.714 |
| 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 |
18:56:44.41 |
+28:43:36.0 |
HIP 93003 |
25.93 |
| 2026-09-20 12:00 |
18:56:42.99 |
+28:42:53.4 |
HIP 93003 |
25.23 |
| 2026-09-21 00:00 |
18:56:41.61 |
+28:42:10.7 |
HIP 93003 |
24.53 |
| 2026-09-21 12:00 |
18:56:40.27 |
+28:41:27.9 |
HIP 93003 |
23.83 |
| 2026-09-22 00:00 |
18:56:38.97 |
+28:40:45.1 |
HIP 93003 |
23.14 |
| 2026-09-22 12:00 |
18:56:37.71 |
+28:40:02.2 |
HIP 93003 |
22.45 |
| 2026-09-23 00:00 |
18:56:36.50 |
+28:39:19.3 |
HIP 93003 |
21.76 |
| 2026-09-23 12:00 |
18:56:35.32 |
+28:38:36.3 |
HIP 93003 |
21.08 |
| 2026-09-24 00:00 |
18:56:34.19 |
+28:37:53.3 |
HIP 93003 |
20.40 |
| 2026-09-24 12:00 |
18:56:33.10 |
+28:37:10.2 |
HIP 93003 |
19.73 |
| 2026-09-25 00:00 |
18:56:32.05 |
+28:36:27.2 |
HIP 93003 |
19.05 |
| 2026-09-25 12:00 |
18:56:31.04 |
+28:35:44.1 |
HIP 93003 |
18.39 |
| 2026-09-26 00:00 |
18:56:30.07 |
+28:35:00.9 |
HIP 93003 |
17.72 |
| 2026-09-26 12:00 |
18:56:29.14 |
+28:34:17.8 |
HIP 93003 |
17.07 |
| 2026-09-27 00:00 |
18:56:28.25 |
+28:33:34.6 |
HIP 93003 |
16.41 |
| 2026-09-27 12:00 |
18:56:27.41 |
+28:32:51.4 |
HIP 93003 |
15.77 |
| 2026-09-28 00:00 |
18:56:26.60 |
+28:32:08.2 |
HIP 93003 |
15.13 |
| 2026-09-28 12:00 |
18:56:25.84 |
+28:31:25.0 |
HIP 93003 |
14.49 |
| 2026-09-29 00:00 |
18:56:25.12 |
+28:30:41.8 |
HIP 93003 |
13.86 |
| 2026-09-29 12:00 |
18:56:24.43 |
+28:29:58.6 |
HIP 93003 |
13.24 |
| 2026-09-30 00:00 |
18:56:23.79 |
+28:29:15.4 |
HIP 93003 |
12.63 |
| 2026-09-30 12:00 |
18:56:23.20 |
+28:28:32.2 |
HIP 93003 |
12.03 |
| 2026-10-01 00:00 |
18:56:22.64 |
+28:27:49.0 |
HIP 93003 |
11.44 |
| 2026-10-01 12:00 |
18:56:22.12 |
+28:27:05.8 |
HIP 93003 |
10.87 |
| 2026-10-02 00:00 |
18:56:21.65 |
+28:26:22.6 |
HIP 93003 |
10.31 |
| 2026-10-02 12:00 |
18:56:21.21 |
+28:25:39.5 |
HIP 93003 |
9.76 |
| 2026-10-03 00:00 |
18:56:20.82 |
+28:24:56.3 |
HIP 93003 |
9.24 |
| 2026-10-03 12:00 |
18:56:20.47 |
+28:24:13.2 |
HIP 93003 |
8.73 |
| 2026-10-04 00:00 |
18:56:20.16 |
+28:23:30.2 |
HIP 93003 |
8.26 |
| 2026-10-04 12:00 |
18:56:19.89 |
+28:22:47.1 |
HIP 93003 |
7.81 |
| 2026-10-05 00:00 |
18:56:19.67 |
+28:22:04.1 |
HIP 93003 |
7.40 |
| 2026-10-05 12:00 |
18:56:19.48 |
+28:21:21.2 |
HIP 93003 |
7.04 |
| 2026-10-06 00:00 |
18:56:19.34 |
+28:20:38.3 |
HIP 93003 |
6.72 |
| 2026-10-06 12:00 |
18:56:19.24 |
+28:19:55.4 |
HIP 93003 |
6.46 |
| 2026-10-07 00:00 |
18:56:19.18 |
+28:19:12.6 |
HIP 93003 |
6.26 |
| 2026-10-07 12:00 |
18:56:19.16 |
+28:18:29.9 |
HIP 93003 |
6.13 |
| 2026-10-08 00:00 |
18:56:19.18 |
+28:17:47.2 |
HIP 93003 |
6.07 |
| 2026-10-08 12:00 |
18:56:19.24 |
+28:17:04.6 |
HIP 93003 |
6.08 |
| 2026-10-09 00:00 |
18:56:19.35 |
+28:16:22.0 |
HIP 92986 |
6.05 |
| 2026-10-09 12:00 |
18:56:19.49 |
+28:15:39.6 |
HIP 92986 |
5.52 |
| 2026-10-10 00:00 |
18:56:19.68 |
+28:14:57.2 |
HIP 92986 |
5.04 |
| 2026-10-10 12:00 |
18:56:19.91 |
+28:14:14.8 |
HIP 92986 |
4.61 |
| 2026-10-11 00:00 |
18:56:20.18 |
+28:13:32.6 |
HIP 92986 |
4.24 |