| Parameter |
Value |
| Designation |
320P/McNaught |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2010-02-21T01:58:51.620160Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:23Z |
| Obs used |
121 |
| NEO |
Yes |
| M1 |
19.600 |
| K1 |
14.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-04-07.0000000 |
| e |
0.68244389 |
| q (au) |
0.985360 |
| a (au) |
3.102949 |
| i (deg) |
4.893564 |
| Ω (om, deg) |
295.955979 |
| ω (w, deg) |
0.665974 |
| M (ma, deg) |
73.916022 |
Magnitude
Scatter + Global Linear
$$
M_a = (20.000 + 5.331\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
20.000 |
| n |
5.331 |
| gf |
1.000 |
| gb |
-0.745 |
| k |
0.981 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
22:59:00.25 |
-19:33:24.0 |
HIP 113399 |
22.17 |
| 2026-06-01 12:00 |
23:03:10.70 |
-18:50:57.7 |
HIP 113762 |
13.68 |
| 2026-06-02 00:00 |
23:07:16.74 |
-18:08:33.2 |
HIP 114042 |
26.44 |
| 2026-06-02 12:00 |
23:11:18.40 |
-17:26:13.3 |
HIP 114446 |
11.72 |
| 2026-06-03 00:00 |
23:15:15.70 |
-16:44:00.9 |
HIP 114832 |
10.34 |
| 2026-06-03 12:00 |
23:19:08.66 |
-16:01:58.8 |
HIP 115170 |
16.89 |
| 2026-06-04 00:00 |
23:22:57.33 |
-15:20:09.5 |
HIP 115404 |
18.33 |
| 2026-06-04 12:00 |
23:26:41.75 |
-14:38:35.2 |
HIP 115687 |
6.56 |
| 2026-06-05 00:00 |
23:30:21.97 |
-13:57:18.4 |
HIP 116007 |
2.15 |
| 2026-06-05 12:00 |
23:33:58.05 |
-13:16:20.9 |
HIP 116326 |
19.14 |
| 2026-06-06 00:00 |
23:37:30.05 |
-12:35:44.7 |
HIP 116593 |
23.79 |
| 2026-06-06 12:00 |
23:40:58.03 |
-11:55:31.5 |
HIP 116878 |
7.62 |
| 2026-06-07 00:00 |
23:44:22.06 |
-11:15:42.8 |
HIP 117093 |
16.69 |
| 2026-06-07 12:00 |
23:47:42.22 |
-10:36:20.0 |
HIP 117212 |
25.70 |
| 2026-06-08 00:00 |
23:50:58.59 |
-09:57:24.5 |
HIP 117541 |
10.87 |
| 2026-06-08 12:00 |
23:54:11.22 |
-09:18:57.2 |
HIP 117843 |
2.57 |
| 2026-06-09 00:00 |
23:57:20.21 |
-08:40:59.2 |
HIP 118219 |
23.37 |
| 2026-06-09 12:00 |
00:00:25.63 |
-08:03:31.2 |
HIP 118294 |
19.45 |
| 2026-06-10 00:00 |
00:03:27.56 |
-07:26:34.1 |
HIP 245 |
23.16 |
| 2026-06-10 12:00 |
00:06:26.08 |
-06:50:08.3 |
HIP 356 |
29.80 |
| 2026-06-11 00:00 |
00:09:21.27 |
-06:14:14.3 |
HIP 849 |
19.77 |
| 2026-06-11 12:00 |
00:12:13.22 |
-05:38:52.6 |
HIP 897 |
18.95 |
| 2026-06-12 00:00 |
00:15:01.99 |
-05:04:03.4 |
HIP 1324 |
24.56 |
| 2026-06-12 12:00 |
00:17:47.67 |
-04:29:46.9 |
HIP 1380 |
8.44 |
| 2026-06-13 00:00 |
00:20:30.34 |
-03:56:03.2 |
HIP 1661 |
11.89 |
| 2026-06-13 12:00 |
00:23:10.07 |
-03:22:52.3 |
HIP 1825 |
13.37 |
| 2026-06-14 00:00 |
00:25:46.95 |
-02:50:14.2 |
HIP 1873 |
34.39 |
| 2026-06-14 12:00 |
00:28:21.04 |
-02:18:08.8 |
HIP 2242 |
12.78 |
| 2026-06-15 00:00 |
00:30:52.43 |
-01:46:35.8 |
HIP 2496 |
12.11 |
| 2026-06-15 12:00 |
00:33:21.18 |
-01:15:35.2 |
HIP 2735 |
23.89 |
| 2026-06-16 00:00 |
00:35:47.37 |
-00:45:06.5 |
HIP 2787 |
15.23 |
| 2026-06-16 12:00 |
00:38:11.07 |
-00:15:09.6 |
HIP 2994 |
15.14 |
| 2026-06-17 00:00 |
00:40:32.35 |
+00:14:15.9 |
HIP 3278 |
18.94 |
| 2026-06-17 12:00 |
00:42:51.28 |
+00:43:10.5 |
HIP 3355 |
2.32 |
| 2026-06-18 00:00 |
00:45:07.92 |
+01:11:34.5 |
HIP 3655 |
32.61 |
| 2026-06-18 12:00 |
00:47:22.35 |
+01:39:28.4 |
HIP 3655 |
11.07 |
| 2026-06-19 00:00 |
00:49:34.62 |
+02:06:52.6 |
HIP 3758 |
42.09 |
| 2026-06-19 12:00 |
00:51:44.79 |
+02:33:47.5 |
HIP 3973 |
14.79 |
| 2026-06-20 00:00 |
00:53:52.94 |
+03:00:13.8 |
HIP 4186 |
18.94 |
| 2026-06-20 12:00 |
00:55:59.12 |
+03:26:11.8 |
HIP 4370 |
14.12 |
| 2026-06-21 00:00 |
00:58:03.38 |
+03:51:42.0 |
HIP 4582 |
22.83 |
| 2026-06-21 12:00 |
01:00:05.78 |
+04:16:45.1 |
HIP 4582 |
21.25 |
| 2026-06-22 00:00 |
01:02:06.38 |
+04:41:21.4 |
HIP 4737 |
20.76 |