| Parameter |
Value |
| Designation |
C/2012 K6 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-05-21T11:03:28.212480Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:10Z |
| Obs used |
1091 |
| NEO |
- |
| M1 |
8.900 |
| K1 |
7.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-12-31.0000000 |
| e |
0.99919878 |
| q (au) |
3.353032 |
| a (au) |
4184.883889 |
| i (deg) |
135.215103 |
| Ω (om, deg) |
206.898541 |
| ω (w, deg) |
338.826785 |
| M (ma, deg) |
0.000814 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.021 + 3.183\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.021 |
| n |
3.183 |
| gf |
0.997 |
| gb |
-1.000 |
| k |
1.000 |
| δ90 |
9.993 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2012-04-20 |
2013-05-20 |
+12.1573 |
-6.871 |
| 2013-06-02 |
2014-01-30 |
-1.7355 |
+0.738 |
| 2014-01-30 |
2015-04-09 |
-2.5207 |
+1.571 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
04:44:50.26 |
+59:46:06.7 |
HIP 22080 |
6.59 |
| 2026-05-12 12:00 |
04:44:57.10 |
+59:45:55.4 |
HIP 22080 |
6.71 |
| 2026-05-13 00:00 |
04:45:03.97 |
+59:45:44.4 |
HIP 22080 |
6.94 |
| 2026-05-13 12:00 |
04:45:10.85 |
+59:45:33.7 |
HIP 22110 |
7.18 |
| 2026-05-14 00:00 |
04:45:17.76 |
+59:45:23.3 |
HIP 22110 |
7.11 |
| 2026-05-14 12:00 |
04:45:24.68 |
+59:45:13.1 |
HIP 22110 |
7.13 |
| 2026-05-15 00:00 |
04:45:31.63 |
+59:45:03.3 |
HIP 22110 |
7.27 |
| 2026-05-15 12:00 |
04:45:38.59 |
+59:44:53.8 |
HIP 22110 |
7.50 |
| 2026-05-16 00:00 |
04:45:45.57 |
+59:44:44.6 |
HIP 22110 |
7.82 |
| 2026-05-16 12:00 |
04:45:52.57 |
+59:44:35.7 |
HIP 22110 |
8.22 |
| 2026-05-17 00:00 |
04:45:59.59 |
+59:44:27.0 |
HIP 22110 |
8.69 |
| 2026-05-17 12:00 |
04:46:06.62 |
+59:44:18.7 |
HIP 22110 |
9.22 |
| 2026-05-18 00:00 |
04:46:13.68 |
+59:44:10.7 |
HIP 22110 |
9.81 |
| 2026-05-18 12:00 |
04:46:20.74 |
+59:44:02.9 |
HIP 22110 |
10.43 |
| 2026-05-19 00:00 |
04:46:27.82 |
+59:43:55.5 |
HIP 22110 |
11.09 |
| 2026-05-19 12:00 |
04:46:34.92 |
+59:43:48.4 |
HIP 22110 |
11.78 |
| 2026-05-20 00:00 |
04:46:42.03 |
+59:43:41.5 |
HIP 22110 |
12.49 |
| 2026-05-20 12:00 |
04:46:49.15 |
+59:43:35.0 |
HIP 22110 |
13.23 |
| 2026-05-21 00:00 |
04:46:56.29 |
+59:43:28.7 |
HIP 22110 |
13.98 |
| 2026-05-21 12:00 |
04:47:03.44 |
+59:43:22.8 |
HIP 22110 |
14.75 |
| 2026-05-22 00:00 |
04:47:10.60 |
+59:43:17.1 |
HIP 22110 |
15.53 |
| 2026-05-22 12:00 |
04:47:17.78 |
+59:43:11.7 |
HIP 22321 |
16.11 |
| 2026-05-23 00:00 |
04:47:24.96 |
+59:43:06.7 |
HIP 22321 |
15.55 |
| 2026-05-23 12:00 |
04:47:32.16 |
+59:43:01.9 |
HIP 22321 |
15.02 |
| 2026-05-24 00:00 |
04:47:39.37 |
+59:42:57.4 |
HIP 22321 |
14.54 |
| 2026-05-24 12:00 |
04:47:46.58 |
+59:42:53.2 |
HIP 22321 |
14.10 |
| 2026-05-25 00:00 |
04:47:53.81 |
+59:42:49.3 |
HIP 22321 |
13.71 |
| 2026-05-25 12:00 |
04:48:01.04 |
+59:42:45.7 |
HIP 22321 |
13.38 |
| 2026-05-26 00:00 |
04:48:08.28 |
+59:42:42.4 |
HIP 22321 |
13.11 |
| 2026-05-26 12:00 |
04:48:15.53 |
+59:42:39.4 |
HIP 22321 |
12.90 |
| 2026-05-27 00:00 |
04:48:22.79 |
+59:42:36.7 |
HIP 22321 |
12.76 |
| 2026-05-27 12:00 |
04:48:30.06 |
+59:42:34.2 |
HIP 22434 |
12.43 |
| 2026-05-28 00:00 |
04:48:37.33 |
+59:42:32.1 |
HIP 22434 |
11.76 |
| 2026-05-28 12:00 |
04:48:44.60 |
+59:42:30.2 |
HIP 22434 |
11.12 |
| 2026-05-29 00:00 |
04:48:51.89 |
+59:42:28.6 |
HIP 22434 |
10.54 |
| 2026-05-29 12:00 |
04:48:59.18 |
+59:42:27.4 |
HIP 22434 |
10.00 |
| 2026-05-30 00:00 |
04:49:06.47 |
+59:42:26.4 |
HIP 22434 |
9.53 |
| 2026-05-30 12:00 |
04:49:13.77 |
+59:42:25.7 |
HIP 22434 |
9.13 |
| 2026-05-31 00:00 |
04:49:21.07 |
+59:42:25.2 |
HIP 22434 |
8.81 |
| 2026-05-31 12:00 |
04:49:28.37 |
+59:42:25.1 |
HIP 22434 |
8.59 |
| 2026-06-01 00:00 |
04:49:35.68 |
+59:42:25.3 |
HIP 22434 |
8.47 |
| 2026-06-01 12:00 |
04:49:42.99 |
+59:42:25.7 |
HIP 22434 |
8.45 |
| 2026-06-02 00:00 |
04:49:50.30 |
+59:42:26.5 |
HIP 22434 |
8.54 |