| 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 |
1.000 |
| gb |
-0.866 |
| k |
0.999 |
| 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 |
03:22:33.11 |
+06:43:26.4 |
HIP 15738 |
5.69 |
| 2026-03-26 12:00 |
03:22:35.78 |
+06:43:54.9 |
HIP 15738 |
4.92 |
| 2026-03-27 00:00 |
03:22:38.46 |
+06:44:23.3 |
HIP 15738 |
4.16 |
| 2026-03-27 12:00 |
03:22:41.18 |
+06:44:51.7 |
HIP 15738 |
3.43 |
| 2026-03-28 00:00 |
03:22:43.92 |
+06:45:20.2 |
HIP 15738 |
2.75 |
| 2026-03-28 12:00 |
03:22:46.68 |
+06:45:48.7 |
HIP 15738 |
2.17 |
| 2026-03-29 00:00 |
03:22:49.47 |
+06:46:17.1 |
HIP 15738 |
1.80 |
| 2026-03-29 12:00 |
03:22:52.29 |
+06:46:45.6 |
HIP 15738 |
1.80 |
| 2026-03-30 00:00 |
03:22:55.13 |
+06:47:14.0 |
HIP 15738 |
2.16 |
| 2026-03-30 12:00 |
03:22:57.99 |
+06:47:42.4 |
HIP 15738 |
2.75 |
| 2026-03-31 00:00 |
03:23:00.88 |
+06:48:10.9 |
HIP 15738 |
3.46 |
| 2026-03-31 12:00 |
03:23:03.79 |
+06:48:39.3 |
HIP 15738 |
4.23 |
| 2026-04-01 00:00 |
03:23:06.73 |
+06:49:07.7 |
HIP 15738 |
5.04 |
| 2026-04-01 12:00 |
03:23:09.69 |
+06:49:36.2 |
HIP 15738 |
5.87 |
| 2026-04-02 00:00 |
03:23:12.67 |
+06:50:04.6 |
HIP 15738 |
6.72 |
| 2026-04-02 12:00 |
03:23:15.68 |
+06:50:33.0 |
HIP 15738 |
7.58 |
| 2026-04-03 00:00 |
03:23:18.71 |
+06:51:01.3 |
HIP 15738 |
8.45 |
| 2026-04-03 12:00 |
03:23:21.76 |
+06:51:29.7 |
HIP 15738 |
9.33 |
| 2026-04-04 00:00 |
03:23:24.84 |
+06:51:58.1 |
HIP 15738 |
10.21 |
| 2026-04-04 12:00 |
03:23:27.93 |
+06:52:26.4 |
HIP 15738 |
11.11 |
| 2026-04-05 00:00 |
03:23:31.05 |
+06:52:54.7 |
HIP 15738 |
12.01 |
| 2026-04-05 12:00 |
03:23:34.19 |
+06:53:23.0 |
HIP 15738 |
12.91 |
| 2026-04-06 00:00 |
03:23:37.35 |
+06:53:51.3 |
HIP 15875 |
13.77 |
| 2026-04-06 12:00 |
03:23:40.54 |
+06:54:19.5 |
HIP 15875 |
12.86 |
| 2026-04-07 00:00 |
03:23:43.74 |
+06:54:47.8 |
HIP 15875 |
11.94 |
| 2026-04-07 12:00 |
03:23:46.96 |
+06:55:16.0 |
HIP 15875 |
11.03 |
| 2026-04-08 00:00 |
03:23:50.21 |
+06:55:44.1 |
HIP 15875 |
10.11 |
| 2026-04-08 12:00 |
03:23:53.47 |
+06:56:12.3 |
HIP 15875 |
9.19 |
| 2026-04-09 00:00 |
03:23:56.76 |
+06:56:40.4 |
HIP 15875 |
8.27 |
| 2026-04-09 12:00 |
03:24:00.06 |
+06:57:08.5 |
HIP 15875 |
7.36 |
| 2026-04-10 00:00 |
03:24:03.39 |
+06:57:36.6 |
HIP 15875 |
6.44 |
| 2026-04-10 12:00 |
03:24:06.73 |
+06:58:04.6 |
HIP 15875 |
5.53 |
| 2026-04-11 00:00 |
03:24:10.10 |
+06:58:32.6 |
HIP 15875 |
4.63 |
| 2026-04-11 12:00 |
03:24:13.48 |
+06:59:00.6 |
HIP 15875 |
3.76 |
| 2026-04-12 00:00 |
03:24:16.88 |
+06:59:28.5 |
HIP 15875 |
2.94 |
| 2026-04-12 12:00 |
03:24:20.30 |
+06:59:56.4 |
HIP 15875 |
2.23 |
| 2026-04-13 00:00 |
03:24:23.73 |
+07:00:24.2 |
HIP 15875 |
1.78 |
| 2026-04-13 12:00 |
03:24:27.19 |
+07:00:52.0 |
HIP 15875 |
1.80 |
| 2026-04-14 00:00 |
03:24:30.66 |
+07:01:19.8 |
HIP 15875 |
2.28 |
| 2026-04-14 12:00 |
03:24:34.15 |
+07:01:47.5 |
HIP 15875 |
3.01 |
| 2026-04-15 00:00 |
03:24:37.65 |
+07:02:15.1 |
HIP 15875 |
3.86 |
| 2026-04-15 12:00 |
03:24:41.17 |
+07:02:42.8 |
HIP 15875 |
4.76 |
| 2026-04-16 00:00 |
03:24:44.71 |
+07:03:10.3 |
HIP 15875 |
5.70 |