| Parameter |
Value |
| Designation |
C/2013 G7 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2014-03-18T16:01:39.025920Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:34Z |
| Obs used |
305 |
| NEO |
- |
| M1 |
6.000 |
| K1 |
12.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-07-23.0000000 |
| e |
0.99786135 |
| q (au) |
4.677407 |
| a (au) |
2187.083310 |
| i (deg) |
105.110084 |
| Ω (om, deg) |
48.402717 |
| ω (w, deg) |
218.263829 |
| M (ma, deg) |
359.997700 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.939 + 3.225\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.939 |
| n |
3.225 |
| gf |
0.999 |
| gb |
-0.866 |
| k |
0.999 |
| δ90 |
9.999 |
| 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 |
03:30:42.67 |
+07:39:22.9 |
HIP 16464 |
20.88 |
| 2026-06-01 12:00 |
03:30:46.51 |
+07:39:41.1 |
HIP 16464 |
20.04 |
| 2026-06-02 00:00 |
03:30:50.34 |
+07:39:59.2 |
HIP 16464 |
19.23 |
| 2026-06-02 12:00 |
03:30:54.16 |
+07:40:17.1 |
HIP 16464 |
18.43 |
| 2026-06-03 00:00 |
03:30:57.97 |
+07:40:34.9 |
HIP 16464 |
17.65 |
| 2026-06-03 12:00 |
03:31:01.78 |
+07:40:52.6 |
HIP 16464 |
16.90 |
| 2026-06-04 00:00 |
03:31:05.57 |
+07:41:10.1 |
HIP 16464 |
16.18 |
| 2026-06-04 12:00 |
03:31:09.35 |
+07:41:27.4 |
HIP 16464 |
15.48 |
| 2026-06-05 00:00 |
03:31:13.12 |
+07:41:44.7 |
HIP 16464 |
14.82 |
| 2026-06-05 12:00 |
03:31:16.88 |
+07:42:01.7 |
HIP 16464 |
14.19 |
| 2026-06-06 00:00 |
03:31:20.63 |
+07:42:18.7 |
HIP 16464 |
13.61 |
| 2026-06-06 12:00 |
03:31:24.37 |
+07:42:35.5 |
HIP 16464 |
13.07 |
| 2026-06-07 00:00 |
03:31:28.09 |
+07:42:52.1 |
HIP 16464 |
12.59 |
| 2026-06-07 12:00 |
03:31:31.80 |
+07:43:08.6 |
HIP 16464 |
12.16 |
| 2026-06-08 00:00 |
03:31:35.50 |
+07:43:24.9 |
HIP 16464 |
11.79 |
| 2026-06-08 12:00 |
03:31:39.19 |
+07:43:41.1 |
HIP 16464 |
11.49 |
| 2026-06-09 00:00 |
03:31:42.86 |
+07:43:57.2 |
HIP 16464 |
11.27 |
| 2026-06-09 12:00 |
03:31:46.52 |
+07:44:13.1 |
HIP 16464 |
11.12 |
| 2026-06-10 00:00 |
03:31:50.17 |
+07:44:28.8 |
HIP 16464 |
11.05 |
| 2026-06-10 12:00 |
03:31:53.80 |
+07:44:44.4 |
HIP 16464 |
11.05 |
| 2026-06-11 00:00 |
03:31:57.42 |
+07:44:59.8 |
HIP 16464 |
11.14 |
| 2026-06-11 12:00 |
03:32:01.03 |
+07:45:15.1 |
HIP 16464 |
11.30 |
| 2026-06-12 00:00 |
03:32:04.62 |
+07:45:30.3 |
HIP 16464 |
11.52 |
| 2026-06-12 12:00 |
03:32:08.20 |
+07:45:45.2 |
HIP 16464 |
11.82 |
| 2026-06-13 00:00 |
03:32:11.76 |
+07:46:00.1 |
HIP 16464 |
12.17 |
| 2026-06-13 12:00 |
03:32:15.30 |
+07:46:14.7 |
HIP 16464 |
12.58 |
| 2026-06-14 00:00 |
03:32:18.83 |
+07:46:29.2 |
HIP 16464 |
13.03 |
| 2026-06-14 12:00 |
03:32:22.35 |
+07:46:43.6 |
HIP 16464 |
13.53 |
| 2026-06-15 00:00 |
03:32:25.85 |
+07:46:57.8 |
HIP 16464 |
14.06 |
| 2026-06-15 12:00 |
03:32:29.33 |
+07:47:11.8 |
HIP 16464 |
14.62 |
| 2026-06-16 00:00 |
03:32:32.79 |
+07:47:25.7 |
HIP 16464 |
15.22 |
| 2026-06-16 12:00 |
03:32:36.24 |
+07:47:39.4 |
HIP 16464 |
15.83 |
| 2026-06-17 00:00 |
03:32:39.67 |
+07:47:53.0 |
HIP 16464 |
16.47 |
| 2026-06-17 12:00 |
03:32:43.08 |
+07:48:06.4 |
HIP 16464 |
17.12 |
| 2026-06-18 00:00 |
03:32:46.48 |
+07:48:19.7 |
HIP 16464 |
17.78 |
| 2026-06-18 12:00 |
03:32:49.85 |
+07:48:32.8 |
HIP 16464 |
18.46 |
| 2026-06-19 00:00 |
03:32:53.21 |
+07:48:45.7 |
HIP 16464 |
19.15 |
| 2026-06-19 12:00 |
03:32:56.55 |
+07:48:58.5 |
HIP 16464 |
19.85 |
| 2026-06-20 00:00 |
03:32:59.87 |
+07:49:11.1 |
HIP 16464 |
20.55 |
| 2026-06-20 12:00 |
03:33:03.17 |
+07:49:23.5 |
HIP 16464 |
21.26 |
| 2026-06-21 00:00 |
03:33:06.46 |
+07:49:35.8 |
HIP 16464 |
21.97 |
| 2026-06-21 12:00 |
03:33:09.72 |
+07:49:47.9 |
HIP 16560 |
22.63 |
| 2026-06-22 00:00 |
03:33:12.96 |
+07:49:59.9 |
HIP 16560 |
22.82 |