| 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) |
| 2026-06-01 00:00 |
19:12:00.95 |
+29:23:51.7 |
HIP 94412 |
15.61 |
| 2026-06-01 12:00 |
19:11:56.80 |
+29:24:24.8 |
HIP 94251 |
16.45 |
| 2026-06-02 00:00 |
19:11:52.62 |
+29:24:57.5 |
HIP 94251 |
16.32 |
| 2026-06-02 12:00 |
19:11:48.41 |
+29:25:29.8 |
HIP 94251 |
16.24 |
| 2026-06-03 00:00 |
19:11:44.18 |
+29:26:01.7 |
HIP 94251 |
16.22 |
| 2026-06-03 12:00 |
19:11:39.92 |
+29:26:33.3 |
HIP 94251 |
16.27 |
| 2026-06-04 00:00 |
19:11:35.64 |
+29:27:04.4 |
HIP 94251 |
16.37 |
| 2026-06-04 12:00 |
19:11:31.33 |
+29:27:35.2 |
HIP 94251 |
16.54 |
| 2026-06-05 00:00 |
19:11:27.00 |
+29:28:05.6 |
HIP 94251 |
16.77 |
| 2026-06-05 12:00 |
19:11:22.65 |
+29:28:35.6 |
HIP 94251 |
17.05 |
| 2026-06-06 00:00 |
19:11:18.27 |
+29:29:05.2 |
HIP 94251 |
17.39 |
| 2026-06-06 12:00 |
19:11:13.87 |
+29:29:34.4 |
HIP 94251 |
17.78 |
| 2026-06-07 00:00 |
19:11:09.45 |
+29:30:03.2 |
HIP 94251 |
18.22 |
| 2026-06-07 12:00 |
19:11:05.00 |
+29:30:31.6 |
HIP 94251 |
18.70 |
| 2026-06-08 00:00 |
19:11:00.54 |
+29:30:59.6 |
HIP 94251 |
19.23 |
| 2026-06-08 12:00 |
19:10:56.05 |
+29:31:27.2 |
HIP 94251 |
19.79 |
| 2026-06-09 00:00 |
19:10:51.54 |
+29:31:54.5 |
HIP 94117 |
20.01 |
| 2026-06-09 12:00 |
19:10:47.01 |
+29:32:21.3 |
HIP 94117 |
19.42 |
| 2026-06-10 00:00 |
19:10:42.46 |
+29:32:47.7 |
HIP 94117 |
18.86 |
| 2026-06-10 12:00 |
19:10:37.88 |
+29:33:13.6 |
HIP 94117 |
18.35 |
| 2026-06-11 00:00 |
19:10:33.29 |
+29:33:39.2 |
HIP 94117 |
17.88 |
| 2026-06-11 12:00 |
19:10:28.68 |
+29:34:04.4 |
HIP 94117 |
17.46 |
| 2026-06-12 00:00 |
19:10:24.04 |
+29:34:29.1 |
HIP 94117 |
17.09 |
| 2026-06-12 12:00 |
19:10:19.39 |
+29:34:53.5 |
HIP 94117 |
16.77 |
| 2026-06-13 00:00 |
19:10:14.72 |
+29:35:17.4 |
HIP 94117 |
16.51 |
| 2026-06-13 12:00 |
19:10:10.03 |
+29:35:40.9 |
HIP 94117 |
16.32 |
| 2026-06-14 00:00 |
19:10:05.33 |
+29:36:03.9 |
HIP 94117 |
16.18 |
| 2026-06-14 12:00 |
19:10:00.60 |
+29:36:26.6 |
HIP 94117 |
16.11 |
| 2026-06-15 00:00 |
19:09:55.86 |
+29:36:48.8 |
HIP 94117 |
16.11 |
| 2026-06-15 12:00 |
19:09:51.10 |
+29:37:10.6 |
HIP 94117 |
16.18 |
| 2026-06-16 00:00 |
19:09:46.33 |
+29:37:31.9 |
HIP 94117 |
16.31 |
| 2026-06-16 12:00 |
19:09:41.54 |
+29:37:52.9 |
HIP 94117 |
16.50 |
| 2026-06-17 00:00 |
19:09:36.73 |
+29:38:13.4 |
HIP 94117 |
16.76 |
| 2026-06-17 12:00 |
19:09:31.91 |
+29:38:33.4 |
HIP 94117 |
17.08 |
| 2026-06-18 00:00 |
19:09:27.07 |
+29:38:53.1 |
HIP 94117 |
17.45 |
| 2026-06-18 12:00 |
19:09:22.22 |
+29:39:12.3 |
HIP 94117 |
17.88 |
| 2026-06-19 00:00 |
19:09:17.35 |
+29:39:31.1 |
HIP 94117 |
18.36 |
| 2026-06-19 12:00 |
19:09:12.47 |
+29:39:49.4 |
HIP 94117 |
18.88 |
| 2026-06-20 00:00 |
19:09:07.58 |
+29:40:07.3 |
HIP 93960 |
17.88 |
| 2026-06-20 12:00 |
19:09:02.67 |
+29:40:24.7 |
HIP 93960 |
16.80 |
| 2026-06-21 00:00 |
19:08:57.75 |
+29:40:41.8 |
HIP 93960 |
15.72 |
| 2026-06-21 12:00 |
19:08:52.82 |
+29:40:58.4 |
HIP 93960 |
14.65 |
| 2026-06-22 00:00 |
19:08:47.88 |
+29:41:14.5 |
HIP 93960 |
13.58 |