| Parameter |
Value |
| Designation |
220P/McNaught |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2020-12-10T14:03:36.567360Z |
| Orbit solution date (soln_date, UTC) |
2026-10-01T14:42:13Z |
| Obs used |
2099 |
| NEO |
- |
| M1 |
4.600 |
| K1 |
41.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2022-12-12.0000000 |
| e |
0.50142026 |
| q (au) |
1.554320 |
| a (au) |
3.117495 |
| i (deg) |
8.128035 |
| Ω (om, deg) |
150.104395 |
| ω (w, deg) |
180.599147 |
| M (ma, deg) |
130.966068 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.168 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.168 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-25 00:00 |
03:32:59.32 |
+06:39:42.6 |
HIP 16541 |
1.15 |
| 2026-09-25 12:00 |
03:33:02.32 |
+06:36:07.1 |
HIP 16541 |
2.52 |
| 2026-09-26 00:00 |
03:33:04.69 |
+06:32:30.3 |
HIP 16541 |
6.18 |
| 2026-09-26 12:00 |
03:33:06.43 |
+06:28:52.4 |
HIP 16541 |
9.83 |
| 2026-09-27 00:00 |
03:33:07.54 |
+06:25:13.3 |
HIP 16541 |
13.49 |
| 2026-09-27 12:00 |
03:33:08.03 |
+06:21:33.2 |
HIP 16541 |
17.14 |
| 2026-09-28 00:00 |
03:33:07.88 |
+06:17:52.1 |
HIP 16541 |
20.80 |
| 2026-09-28 12:00 |
03:33:07.12 |
+06:14:10.0 |
HIP 16663 |
23.04 |
| 2026-09-29 00:00 |
03:33:05.73 |
+06:10:26.9 |
HIP 16663 |
21.68 |
| 2026-09-29 12:00 |
03:33:03.72 |
+06:06:43.0 |
HIP 16663 |
21.06 |
| 2026-09-30 00:00 |
03:33:01.10 |
+06:02:58.2 |
HIP 16663 |
21.25 |
| 2026-09-30 12:00 |
03:32:57.85 |
+05:59:12.7 |
HIP 16663 |
22.26 |
| 2026-10-01 00:00 |
03:32:53.99 |
+05:55:26.4 |
HIP 16663 |
24.01 |
| 2026-10-01 12:00 |
03:32:49.51 |
+05:51:39.5 |
HIP 16663 |
26.36 |
| 2026-10-02 00:00 |
03:32:44.43 |
+05:47:51.9 |
HIP 16663 |
29.20 |
| 2026-10-02 12:00 |
03:32:38.73 |
+05:44:03.7 |
HIP 16530 |
28.95 |
| 2026-10-03 00:00 |
03:32:32.43 |
+05:40:15.1 |
HIP 16530 |
25.40 |
| 2026-10-03 12:00 |
03:32:25.53 |
+05:36:26.0 |
HIP 16530 |
22.09 |
| 2026-10-04 00:00 |
03:32:18.03 |
+05:32:36.5 |
HIP 16530 |
19.18 |
| 2026-10-04 12:00 |
03:32:09.93 |
+05:28:46.6 |
HIP 16530 |
16.94 |
| 2026-10-05 00:00 |
03:32:01.25 |
+05:24:56.5 |
HIP 16530 |
15.72 |
| 2026-10-05 12:00 |
03:31:51.97 |
+05:21:06.2 |
HIP 16530 |
15.82 |
| 2026-10-06 00:00 |
03:31:42.11 |
+05:17:15.7 |
HIP 16362 |
14.53 |
| 2026-10-06 12:00 |
03:31:31.68 |
+05:13:25.1 |
HIP 16363 |
11.75 |
| 2026-10-07 00:00 |
03:31:20.67 |
+05:09:34.6 |
HIP 16363 |
8.23 |
| 2026-10-07 12:00 |
03:31:09.09 |
+05:05:44.1 |
HIP 16363 |
6.34 |
| 2026-10-08 00:00 |
03:30:56.96 |
+05:01:53.7 |
HIP 16363 |
7.62 |
| 2026-10-08 12:00 |
03:30:44.26 |
+04:58:03.5 |
HIP 16363 |
11.13 |
| 2026-10-09 00:00 |
03:30:31.02 |
+04:54:13.5 |
HIP 16363 |
15.50 |
| 2026-10-09 12:00 |
03:30:17.23 |
+04:50:23.9 |
HIP 16363 |
20.24 |
| 2026-10-10 00:00 |
03:30:02.91 |
+04:46:34.7 |
HIP 16363 |
25.18 |
| 2026-10-10 12:00 |
03:29:48.06 |
+04:42:45.9 |
HIP 16201 |
26.79 |
| 2026-10-11 00:00 |
03:29:32.69 |
+04:38:57.7 |
HIP 16201 |
21.46 |
| 2026-10-11 12:00 |
03:29:16.80 |
+04:35:10.1 |
HIP 16201 |
16.11 |
| 2026-10-12 00:00 |
03:29:00.41 |
+04:31:23.2 |
HIP 16201 |
10.86 |
| 2026-10-12 12:00 |
03:28:43.52 |
+04:27:37.1 |
HIP 16201 |
6.19 |
| 2026-10-13 00:00 |
03:28:26.14 |
+04:23:51.8 |
HIP 16201 |
4.86 |
| 2026-10-13 12:00 |
03:28:08.28 |
+04:20:07.3 |
HIP 16201 |
8.76 |
| 2026-10-14 00:00 |
03:27:49.95 |
+04:16:23.9 |
HIP 16155 |
8.95 |
| 2026-10-14 12:00 |
03:27:31.15 |
+04:12:41.4 |
HIP 16155 |
10.53 |
| 2026-10-15 00:00 |
03:27:11.90 |
+04:09:00.1 |
HIP 16155 |
14.72 |
| 2026-10-15 12:00 |
03:26:52.20 |
+04:05:20.0 |
HIP 16155 |
19.99 |
| 2026-10-16 00:00 |
03:26:32.07 |
+04:01:41.1 |
HIP 16155 |
25.75 |