| 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
$$
M_a = (2.681 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
2.681 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.998 |
| 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) |
| 2026-03-26 00:00 |
19:15:59.43 |
+27:32:30.5 |
HIP 94679 |
5.18 |
| 2026-03-26 12:00 |
19:16:00.31 |
+27:33:27.0 |
HIP 94679 |
6.14 |
| 2026-03-27 00:00 |
19:16:01.15 |
+27:34:23.6 |
HIP 94679 |
7.10 |
| 2026-03-27 12:00 |
19:16:01.96 |
+27:35:20.2 |
HIP 94679 |
8.06 |
| 2026-03-28 00:00 |
19:16:02.72 |
+27:36:16.9 |
HIP 94679 |
9.02 |
| 2026-03-28 12:00 |
19:16:03.44 |
+27:37:13.6 |
HIP 94679 |
9.97 |
| 2026-03-29 00:00 |
19:16:04.12 |
+27:38:10.3 |
HIP 94679 |
10.93 |
| 2026-03-29 12:00 |
19:16:04.76 |
+27:39:07.1 |
HIP 94679 |
11.89 |
| 2026-03-30 00:00 |
19:16:05.36 |
+27:40:04.0 |
HIP 94679 |
12.85 |
| 2026-03-30 12:00 |
19:16:05.91 |
+27:41:00.8 |
HIP 94679 |
13.80 |
| 2026-03-31 00:00 |
19:16:06.43 |
+27:41:57.7 |
HIP 94685 |
13.70 |
| 2026-03-31 12:00 |
19:16:06.91 |
+27:42:54.6 |
HIP 94685 |
12.77 |
| 2026-04-01 00:00 |
19:16:07.34 |
+27:43:51.5 |
HIP 94685 |
11.85 |
| 2026-04-01 12:00 |
19:16:07.74 |
+27:44:48.5 |
HIP 94685 |
10.92 |
| 2026-04-02 00:00 |
19:16:08.09 |
+27:45:45.4 |
HIP 94685 |
10.00 |
| 2026-04-02 12:00 |
19:16:08.40 |
+27:46:42.4 |
HIP 94685 |
9.09 |
| 2026-04-03 00:00 |
19:16:08.67 |
+27:47:39.4 |
HIP 94685 |
8.18 |
| 2026-04-03 12:00 |
19:16:08.90 |
+27:48:36.3 |
HIP 94685 |
7.28 |
| 2026-04-04 00:00 |
19:16:09.09 |
+27:49:33.3 |
HIP 94685 |
6.39 |
| 2026-04-04 12:00 |
19:16:09.24 |
+27:50:30.3 |
HIP 94685 |
5.51 |
| 2026-04-05 00:00 |
19:16:09.35 |
+27:51:27.2 |
HIP 94685 |
4.66 |
| 2026-04-05 12:00 |
19:16:09.41 |
+27:52:24.2 |
HIP 94685 |
3.86 |
| 2026-04-06 00:00 |
19:16:09.43 |
+27:53:21.1 |
HIP 94685 |
3.13 |
| 2026-04-06 12:00 |
19:16:09.42 |
+27:54:18.1 |
HIP 94685 |
2.54 |
| 2026-04-07 00:00 |
19:16:09.36 |
+27:55:15.0 |
HIP 94685 |
2.20 |
| 2026-04-07 12:00 |
19:16:09.26 |
+27:56:11.8 |
HIP 94685 |
2.24 |
| 2026-04-08 00:00 |
19:16:09.11 |
+27:57:08.7 |
HIP 94685 |
2.64 |
| 2026-04-08 12:00 |
19:16:08.93 |
+27:58:05.5 |
HIP 94685 |
3.27 |
| 2026-04-09 00:00 |
19:16:08.70 |
+27:59:02.3 |
HIP 94685 |
4.01 |
| 2026-04-09 12:00 |
19:16:08.43 |
+27:59:59.0 |
HIP 94685 |
4.83 |
| 2026-04-10 00:00 |
19:16:08.12 |
+28:00:55.7 |
HIP 94685 |
5.68 |
| 2026-04-10 12:00 |
19:16:07.77 |
+28:01:52.4 |
HIP 94685 |
6.56 |
| 2026-04-11 00:00 |
19:16:07.38 |
+28:02:49.0 |
HIP 94685 |
7.44 |
| 2026-04-11 12:00 |
19:16:06.94 |
+28:03:45.5 |
HIP 94685 |
8.34 |
| 2026-04-12 00:00 |
19:16:06.46 |
+28:04:42.0 |
HIP 94685 |
9.25 |
| 2026-04-12 12:00 |
19:16:05.95 |
+28:05:38.4 |
HIP 94685 |
10.16 |
| 2026-04-13 00:00 |
19:16:05.38 |
+28:06:34.8 |
HIP 94700 |
10.35 |
| 2026-04-13 12:00 |
19:16:04.78 |
+28:07:31.1 |
HIP 94700 |
9.44 |
| 2026-04-14 00:00 |
19:16:04.14 |
+28:08:27.3 |
HIP 94700 |
8.54 |
| 2026-04-14 12:00 |
19:16:03.45 |
+28:09:23.5 |
HIP 94700 |
7.66 |
| 2026-04-15 00:00 |
19:16:02.72 |
+28:10:19.5 |
HIP 94700 |
6.80 |
| 2026-04-15 12:00 |
19:16:01.95 |
+28:11:15.5 |
HIP 94700 |
5.97 |
| 2026-04-16 00:00 |
19:16:01.14 |
+28:12:11.4 |
HIP 94700 |
5.19 |