| Parameter |
Value |
| Designation |
C/2013 J3 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-02-22T21:02:36.003840Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:35Z |
| Obs used |
105 |
| NEO |
- |
| M1 |
6.900 |
| K1 |
14.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-07-03.0000000 |
| e |
0.99795766 |
| q (au) |
3.988692 |
| a (au) |
1952.998658 |
| i (deg) |
118.225398 |
| Ω (om, deg) |
200.757159 |
| ω (w, deg) |
320.958517 |
| M (ma, deg) |
0.001486 |
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 |
-1.000 |
| k |
1.000 |
| 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) |
| 2026-07-29 00:00 |
08:02:35.14 |
+81:57:34.4 |
HIP 39905 |
20.30 |
| 2026-07-29 12:00 |
08:03:00.43 |
+81:57:37.4 |
HIP 39905 |
19.75 |
| 2026-07-30 00:00 |
08:03:25.69 |
+81:57:40.8 |
HIP 39905 |
19.22 |
| 2026-07-30 12:00 |
08:03:50.93 |
+81:57:44.5 |
HIP 39905 |
18.73 |
| 2026-07-31 00:00 |
08:04:16.14 |
+81:57:48.6 |
HIP 39905 |
18.27 |
| 2026-07-31 12:00 |
08:04:41.32 |
+81:57:53.1 |
HIP 39905 |
17.85 |
| 2026-08-01 00:00 |
08:05:06.48 |
+81:57:57.9 |
HIP 39905 |
17.48 |
| 2026-08-01 12:00 |
08:05:31.61 |
+81:58:03.0 |
HIP 39905 |
17.15 |
| 2026-08-02 00:00 |
08:05:56.70 |
+81:58:08.6 |
HIP 39905 |
16.87 |
| 2026-08-02 12:00 |
08:06:21.77 |
+81:58:14.5 |
HIP 39905 |
16.63 |
| 2026-08-03 00:00 |
08:06:46.80 |
+81:58:20.7 |
HIP 39905 |
16.45 |
| 2026-08-03 12:00 |
08:07:11.80 |
+81:58:27.3 |
HIP 39905 |
16.32 |
| 2026-08-04 00:00 |
08:07:36.77 |
+81:58:34.3 |
HIP 39905 |
16.25 |
| 2026-08-04 12:00 |
08:08:01.70 |
+81:58:41.6 |
HIP 39905 |
16.23 |
| 2026-08-05 00:00 |
08:08:26.60 |
+81:58:49.3 |
HIP 39905 |
16.27 |
| 2026-08-05 12:00 |
08:08:51.46 |
+81:58:57.4 |
HIP 39905 |
16.36 |
| 2026-08-06 00:00 |
08:09:16.28 |
+81:59:05.8 |
HIP 40288 |
16.46 |
| 2026-08-06 12:00 |
08:09:41.07 |
+81:59:14.6 |
HIP 40288 |
16.11 |
| 2026-08-07 00:00 |
08:10:05.82 |
+81:59:23.8 |
HIP 40288 |
15.81 |
| 2026-08-07 12:00 |
08:10:30.52 |
+81:59:33.3 |
HIP 40288 |
15.56 |
| 2026-08-08 00:00 |
08:10:55.19 |
+81:59:43.2 |
HIP 40288 |
15.36 |
| 2026-08-08 12:00 |
08:11:19.81 |
+81:59:53.4 |
HIP 40288 |
15.22 |
| 2026-08-09 00:00 |
08:11:44.40 |
+82:00:04.0 |
HIP 40288 |
15.14 |
| 2026-08-09 12:00 |
08:12:08.93 |
+82:00:15.0 |
HIP 40288 |
15.11 |
| 2026-08-10 00:00 |
08:12:33.43 |
+82:00:26.4 |
HIP 40288 |
15.14 |
| 2026-08-10 12:00 |
08:12:57.87 |
+82:00:38.1 |
HIP 40288 |
15.23 |
| 2026-08-11 00:00 |
08:13:22.27 |
+82:00:50.2 |
HIP 40288 |
15.38 |
| 2026-08-11 12:00 |
08:13:46.62 |
+82:01:02.6 |
HIP 40288 |
15.58 |
| 2026-08-12 00:00 |
08:14:10.92 |
+82:01:15.5 |
HIP 40288 |
15.83 |
| 2026-08-12 12:00 |
08:14:35.17 |
+82:01:28.6 |
HIP 40288 |
16.14 |
| 2026-08-13 00:00 |
08:14:59.37 |
+82:01:42.2 |
HIP 40288 |
16.49 |
| 2026-08-13 12:00 |
08:15:23.52 |
+82:01:56.1 |
HIP 40288 |
16.89 |
| 2026-08-14 00:00 |
08:15:47.61 |
+82:02:10.4 |
HIP 40288 |
17.32 |
| 2026-08-14 12:00 |
08:16:11.64 |
+82:02:25.1 |
HIP 40288 |
17.80 |
| 2026-08-15 00:00 |
08:16:35.62 |
+82:02:40.1 |
HIP 40288 |
18.31 |
| 2026-08-15 12:00 |
08:16:59.54 |
+82:02:55.5 |
HIP 40288 |
18.85 |
| 2026-08-16 00:00 |
08:17:23.41 |
+82:03:11.3 |
HIP 40288 |
19.42 |
| 2026-08-16 12:00 |
08:17:47.21 |
+82:03:27.4 |
HIP 40288 |
20.02 |
| 2026-08-17 00:00 |
08:18:10.95 |
+82:03:43.9 |
HIP 40288 |
20.64 |
| 2026-08-17 12:00 |
08:18:34.63 |
+82:04:00.8 |
HIP 40288 |
21.29 |
| 2026-08-18 00:00 |
08:18:58.25 |
+82:04:18.0 |
HIP 40288 |
21.95 |
| 2026-08-18 12:00 |
08:19:21.81 |
+82:04:35.6 |
HIP 40288 |
22.63 |
| 2026-08-19 00:00 |
08:19:45.30 |
+82:04:53.6 |
HIP 41208 |
23.09 |