| Parameter |
Value |
| Designation |
220P/McNaught |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2015-06-13T19:26:15.040320Z |
| Orbit solution date (soln_date, UTC) |
2026-05-28T12:12:25Z |
| Obs used |
518 |
| NEO |
- |
| M1 |
15.300 |
| K1 |
11.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-09-15.0000000 |
| e |
0.50174649 |
| q (au) |
1.551511 |
| a (au) |
3.113899 |
| i (deg) |
8.128883 |
| Ω (om, deg) |
150.126601 |
| ω (w, deg) |
180.751363 |
| M (ma, deg) |
180.306435 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.842 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.842 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.722 |
| k |
0.800 |
| δ90 |
9.995 |
| 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 |
23:58:49.59 |
+01:00:51.3 |
HIP 1 |
18.21 |
| 2026-06-01 12:00 |
00:00:11.37 |
+01:07:03.1 |
HIP 1 |
3.27 |
| 2026-06-02 00:00 |
00:01:33.09 |
+01:13:13.7 |
HIP 51 |
17.34 |
| 2026-06-02 12:00 |
00:02:54.75 |
+01:19:23.2 |
HIP 384 |
30.69 |
| 2026-06-03 00:00 |
00:04:16.35 |
+01:25:31.5 |
HIP 384 |
10.04 |
| 2026-06-03 12:00 |
00:05:37.89 |
+01:31:38.5 |
HIP 384 |
12.91 |
| 2026-06-04 00:00 |
00:06:59.36 |
+01:37:44.3 |
HIP 604 |
5.48 |
| 2026-06-04 12:00 |
00:08:20.78 |
+01:43:48.8 |
HIP 604 |
15.80 |
| 2026-06-05 00:00 |
00:09:42.13 |
+01:49:52.0 |
HIP 870 |
19.89 |
| 2026-06-05 12:00 |
00:11:03.41 |
+01:55:53.8 |
HIP 870 |
9.35 |
| 2026-06-06 00:00 |
00:12:24.62 |
+02:01:54.3 |
HIP 870 |
26.00 |
| 2026-06-06 12:00 |
00:13:45.77 |
+02:07:53.4 |
HIP 1107 |
44.87 |
| 2026-06-07 00:00 |
00:15:06.85 |
+02:13:51.0 |
HIP 1360 |
30.09 |
| 2026-06-07 12:00 |
00:16:27.85 |
+02:19:47.2 |
HIP 1360 |
9.00 |
| 2026-06-08 00:00 |
00:17:48.78 |
+02:25:41.9 |
HIP 1384 |
7.95 |
| 2026-06-08 12:00 |
00:19:09.63 |
+02:31:35.1 |
HIP 1384 |
27.75 |
| 2026-06-09 00:00 |
00:20:30.41 |
+02:37:26.8 |
HIP 1609 |
25.11 |
| 2026-06-09 12:00 |
00:21:51.10 |
+02:43:16.9 |
HIP 1869 |
26.85 |
| 2026-06-10 00:00 |
00:23:11.72 |
+02:49:05.3 |
HIP 1869 |
8.07 |
| 2026-06-10 12:00 |
00:24:32.25 |
+02:54:52.2 |
HIP 1869 |
16.91 |
| 2026-06-11 00:00 |
00:25:52.70 |
+03:00:37.4 |
HIP 2166 |
24.83 |
| 2026-06-11 12:00 |
00:27:13.06 |
+03:06:20.9 |
HIP 2166 |
17.59 |
| 2026-06-12 00:00 |
00:28:33.33 |
+03:12:02.7 |
HIP 2166 |
29.51 |
| 2026-06-12 12:00 |
00:29:53.52 |
+03:17:42.7 |
HIP 2398 |
9.57 |
| 2026-06-13 00:00 |
00:31:13.61 |
+03:23:20.9 |
HIP 2398 |
12.87 |
| 2026-06-13 12:00 |
00:32:33.60 |
+03:28:57.4 |
HIP 2500 |
20.82 |
| 2026-06-14 00:00 |
00:33:53.50 |
+03:34:32.0 |
HIP 2686 |
14.43 |
| 2026-06-14 12:00 |
00:35:13.30 |
+03:40:04.8 |
HIP 2686 |
18.46 |
| 2026-06-15 00:00 |
00:36:33.00 |
+03:45:35.7 |
HIP 2765 |
27.79 |
| 2026-06-15 12:00 |
00:37:52.60 |
+03:51:04.7 |
HIP 3073 |
16.70 |
| 2026-06-16 00:00 |
00:39:12.09 |
+03:56:31.7 |
HIP 3073 |
5.49 |
| 2026-06-16 12:00 |
00:40:31.48 |
+04:01:56.8 |
HIP 3073 |
25.00 |
| 2026-06-17 00:00 |
00:41:50.76 |
+04:07:19.9 |
HIP 3326 |
8.52 |
| 2026-06-17 12:00 |
00:43:09.93 |
+04:12:40.9 |
HIP 3326 |
11.95 |
| 2026-06-18 00:00 |
00:44:28.99 |
+04:18:00.0 |
HIP 3326 |
32.36 |
| 2026-06-18 12:00 |
00:45:47.94 |
+04:23:17.0 |
HIP 3658 |
31.02 |
| 2026-06-19 00:00 |
00:47:06.77 |
+04:28:31.9 |
HIP 3658 |
22.05 |
| 2026-06-19 12:00 |
00:48:25.49 |
+04:33:44.8 |
HIP 3764 |
25.17 |
| 2026-06-20 00:00 |
00:49:44.09 |
+04:38:55.5 |
HIP 3929 |
11.94 |
| 2026-06-20 12:00 |
00:51:02.57 |
+04:44:04.1 |
HIP 3929 |
13.78 |
| 2026-06-21 00:00 |
00:52:20.93 |
+04:49:10.5 |
HIP 4169 |
13.97 |
| 2026-06-21 12:00 |
00:53:39.16 |
+04:54:14.8 |
HIP 4173 |
7.86 |
| 2026-06-22 00:00 |
00:54:57.28 |
+04:59:16.9 |
HIP 4325 |
23.68 |