| Parameter |
Value |
| Designation |
C/2013 E1 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-06-12T02:48:47.306880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:31Z |
| Obs used |
172 |
| NEO |
- |
| M1 |
6.600 |
| K1 |
8.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-06-11.0000000 |
| e |
1.00225843 |
| q (au) |
7.781630 |
| a (au) |
-3445.585444 |
| i (deg) |
158.720377 |
| Ω (om, deg) |
134.028821 |
| ω (w, deg) |
311.425764 |
| M (ma, deg) |
-0.000005 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.562 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.562 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.823 |
| k |
0.800 |
| 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) |
| 2026-09-20 00:00 |
04:32:08.42 |
+41:32:19.6 |
HIP 21067 |
29.32 |
| 2026-09-20 12:00 |
04:32:05.54 |
+41:32:38.6 |
HIP 21067 |
28.79 |
| 2026-09-21 00:00 |
04:32:02.61 |
+41:32:57.5 |
HIP 21067 |
28.28 |
| 2026-09-21 12:00 |
04:31:59.64 |
+41:33:16.2 |
HIP 21067 |
27.76 |
| 2026-09-22 00:00 |
04:31:56.61 |
+41:33:34.8 |
HIP 21067 |
27.25 |
| 2026-09-22 12:00 |
04:31:53.53 |
+41:33:53.2 |
HIP 21067 |
26.74 |
| 2026-09-23 00:00 |
04:31:50.40 |
+41:34:11.5 |
HIP 21067 |
26.24 |
| 2026-09-23 12:00 |
04:31:47.22 |
+41:34:29.7 |
HIP 21067 |
25.74 |
| 2026-09-24 00:00 |
04:31:43.98 |
+41:34:47.7 |
HIP 21067 |
25.25 |
| 2026-09-24 12:00 |
04:31:40.70 |
+41:35:05.5 |
HIP 21067 |
24.76 |
| 2026-09-25 00:00 |
04:31:37.37 |
+41:35:23.3 |
HIP 21067 |
24.29 |
| 2026-09-25 12:00 |
04:31:33.99 |
+41:35:40.8 |
HIP 21067 |
23.83 |
| 2026-09-26 00:00 |
04:31:30.56 |
+41:35:58.2 |
HIP 21067 |
23.38 |
| 2026-09-26 12:00 |
04:31:27.08 |
+41:36:15.5 |
HIP 21067 |
22.94 |
| 2026-09-27 00:00 |
04:31:23.54 |
+41:36:32.6 |
HIP 21067 |
22.51 |
| 2026-09-27 12:00 |
04:31:19.96 |
+41:36:49.6 |
HIP 21067 |
22.10 |
| 2026-09-28 00:00 |
04:31:16.33 |
+41:37:06.3 |
HIP 21067 |
21.71 |
| 2026-09-28 12:00 |
04:31:12.65 |
+41:37:23.0 |
HIP 21067 |
21.34 |
| 2026-09-29 00:00 |
04:31:08.93 |
+41:37:39.5 |
HIP 21067 |
20.99 |
| 2026-09-29 12:00 |
04:31:05.15 |
+41:37:55.8 |
HIP 21067 |
20.67 |
| 2026-09-30 00:00 |
04:31:01.32 |
+41:38:11.9 |
HIP 21067 |
20.36 |
| 2026-09-30 12:00 |
04:30:57.45 |
+41:38:27.9 |
HIP 21067 |
20.09 |
| 2026-10-01 00:00 |
04:30:53.52 |
+41:38:43.7 |
HIP 21067 |
19.85 |
| 2026-10-01 12:00 |
04:30:49.55 |
+41:38:59.3 |
HIP 21067 |
19.63 |
| 2026-10-02 00:00 |
04:30:45.53 |
+41:39:14.8 |
HIP 21067 |
19.45 |
| 2026-10-02 12:00 |
04:30:41.46 |
+41:39:30.1 |
HIP 21067 |
19.31 |
| 2026-10-03 00:00 |
04:30:37.35 |
+41:39:45.2 |
HIP 21067 |
19.20 |
| 2026-10-03 12:00 |
04:30:33.18 |
+41:40:00.1 |
HIP 21067 |
19.13 |
| 2026-10-04 00:00 |
04:30:28.97 |
+41:40:14.9 |
HIP 21067 |
19.10 |
| 2026-10-04 12:00 |
04:30:24.71 |
+41:40:29.5 |
HIP 21067 |
19.11 |
| 2026-10-05 00:00 |
04:30:20.40 |
+41:40:43.9 |
HIP 21067 |
19.16 |
| 2026-10-05 12:00 |
04:30:16.05 |
+41:40:58.1 |
HIP 21067 |
19.26 |
| 2026-10-06 00:00 |
04:30:11.65 |
+41:41:12.1 |
HIP 21067 |
19.40 |
| 2026-10-06 12:00 |
04:30:07.20 |
+41:41:25.9 |
HIP 20886 |
18.61 |
| 2026-10-07 00:00 |
04:30:02.71 |
+41:41:39.6 |
HIP 20886 |
17.75 |
| 2026-10-07 12:00 |
04:29:58.17 |
+41:41:53.0 |
HIP 20886 |
16.88 |
| 2026-10-08 00:00 |
04:29:53.58 |
+41:42:06.3 |
HIP 20886 |
16.01 |
| 2026-10-08 12:00 |
04:29:48.95 |
+41:42:19.4 |
HIP 20886 |
15.13 |
| 2026-10-09 00:00 |
04:29:44.27 |
+41:42:32.2 |
HIP 20886 |
14.24 |
| 2026-10-09 12:00 |
04:29:39.55 |
+41:42:44.9 |
HIP 20886 |
13.35 |
| 2026-10-10 00:00 |
04:29:34.78 |
+41:42:57.4 |
HIP 20886 |
12.46 |
| 2026-10-10 12:00 |
04:29:29.96 |
+41:43:09.7 |
HIP 20886 |
11.57 |
| 2026-10-11 00:00 |
04:29:25.11 |
+41:43:21.7 |
HIP 20886 |
10.67 |