220P/McNaught
| Parameter |
Value |
| Designation |
220P/McNaught |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2009-12-15T05:47:43.941120Z |
| Orbit solution date (soln_date, UTC) |
2024-01-04T23:43:49Z |
| Obs used |
484 |
| NEO |
- |
| M1 |
15.800 |
| K1 |
10.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-09-25.0000000 |
| e |
0.50218227 |
| q (au) |
1.549755 |
| a (au) |
3.113096 |
| i (deg) |
8.131611 |
| Ω (om, deg) |
150.122641 |
| ω (w, deg) |
180.754819 |
| M (ma, deg) |
116.412147 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.849 + 5.712\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.849 |
| n |
5.712 |
| gf |
1.000 |
| gb |
-0.926 |
| 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) |
| 2026-02-03 00:00 |
18:37:16.95 |
-17:38:24.7 |
HIP 91343 |
25.89 |
| 2026-02-03 12:00 |
18:38:33.27 |
-17:37:25.6 |
HIP 91343 |
25.56 |
| 2026-02-04 00:00 |
18:39:49.68 |
-17:36:24.3 |
HIP 91667 |
34.16 |
| 2026-02-04 12:00 |
18:41:06.19 |
-17:35:20.6 |
HIP 91667 |
24.97 |
| 2026-02-05 00:00 |
18:42:22.78 |
-17:34:14.7 |
HIP 91865 |
19.15 |
| 2026-02-05 12:00 |
18:43:39.47 |
-17:33:06.5 |
HIP 91865 |
0.90 |
| 2026-02-06 00:00 |
18:44:56.25 |
-17:31:56.0 |
HIP 92038 |
9.76 |
| 2026-02-06 12:00 |
18:46:13.12 |
-17:30:43.1 |
HIP 92038 |
8.82 |
| 2026-02-07 00:00 |
18:47:30.08 |
-17:29:28.0 |
HIP 92038 |
27.14 |
| 2026-02-07 12:00 |
18:48:47.13 |
-17:28:10.5 |
HIP 92492 |
36.78 |
| 2026-02-08 00:00 |
18:50:04.26 |
-17:26:50.7 |
HIP 92492 |
24.04 |
| 2026-02-08 12:00 |
18:51:21.49 |
-17:25:28.6 |
HIP 92521 |
16.22 |
| 2026-02-09 00:00 |
18:52:38.80 |
-17:24:04.1 |
HIP 92521 |
23.97 |
| 2026-02-09 12:00 |
18:53:56.20 |
-17:22:37.3 |
HIP 92521 |
39.64 |
| 2026-02-10 00:00 |
18:55:13.69 |
-17:21:08.2 |
HIP 92996 |
22.35 |
| 2026-02-10 12:00 |
18:56:31.26 |
-17:19:36.7 |
HIP 92996 |
7.71 |
| 2026-02-11 00:00 |
18:57:48.92 |
-17:18:02.9 |
HIP 92996 |
17.61 |
| 2026-02-11 12:00 |
18:59:06.66 |
-17:16:26.7 |
HIP 93319 |
22.68 |
| 2026-02-12 00:00 |
19:00:24.48 |
-17:14:48.2 |
HIP 93319 |
14.26 |
| 2026-02-12 12:00 |
19:01:42.39 |
-17:13:07.3 |
HIP 93444 |
8.20 |
| 2026-02-13 00:00 |
19:03:00.37 |
-17:11:24.1 |
HIP 93444 |
19.31 |
| 2026-02-13 12:00 |
19:04:18.44 |
-17:09:38.5 |
HIP 93740 |
22.20 |
| 2026-02-14 00:00 |
19:05:36.59 |
-17:07:50.6 |
HIP 93740 |
16.66 |
| 2026-02-14 12:00 |
19:06:54.82 |
-17:06:00.3 |
HIP 93906 |
10.22 |
| 2026-02-15 00:00 |
19:08:13.12 |
-17:04:07.6 |
HIP 94049 |
14.72 |
| 2026-02-15 12:00 |
19:09:31.50 |
-17:02:12.6 |
HIP 94110 |
9.23 |
| 2026-02-16 00:00 |
19:10:49.96 |
-17:00:15.2 |
HIP 94110 |
21.68 |
| 2026-02-16 12:00 |
19:12:08.50 |
-16:58:15.5 |
HIP 94435 |
17.89 |
| 2026-02-17 00:00 |
19:13:27.11 |
-16:56:13.3 |
HIP 94435 |
10.51 |
| 2026-02-17 12:00 |
19:14:45.79 |
-16:54:08.9 |
HIP 94647 |
11.65 |
| 2026-02-18 00:00 |
19:16:04.55 |
-16:52:02.0 |
HIP 94706 |
6.68 |
| 2026-02-18 12:00 |
19:17:23.38 |
-16:49:52.8 |
HIP 94839 |
8.50 |
| 2026-02-19 00:00 |
19:18:42.28 |
-16:47:41.2 |
HIP 94839 |
14.47 |
| 2026-02-19 12:00 |
19:20:01.25 |
-16:45:27.3 |
HIP 95063 |
18.70 |
| 2026-02-20 00:00 |
19:21:20.30 |
-16:43:11.0 |
HIP 95216 |
15.63 |
| 2026-02-20 12:00 |
19:22:39.41 |
-16:40:52.3 |
HIP 95216 |
7.70 |
| 2026-02-21 00:00 |
19:23:58.59 |
-16:38:31.3 |
HIP 95482 |
22.50 |
| 2026-02-21 12:00 |
19:25:17.84 |
-16:36:07.9 |
HIP 95482 |
14.06 |
| 2026-02-22 00:00 |
19:26:37.16 |
-16:33:42.1 |
HIP 95610 |
13.48 |
| 2026-02-22 12:00 |
19:27:56.54 |
-16:31:14.0 |
HIP 95670 |
6.55 |
| 2026-02-23 00:00 |
19:29:16.00 |
-16:28:43.6 |
HIP 95779 |
6.50 |
| 2026-02-23 12:00 |
19:30:35.51 |
-16:26:10.8 |
HIP 96008 |
9.93 |
| 2026-02-24 00:00 |
19:31:55.09 |
-16:23:35.6 |
HIP 96008 |
9.43 |