| Parameter |
Value |
| Designation |
372P/McNaught |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2009-04-21T12:58:57.285120Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:37Z |
| Obs used |
438 |
| NEO |
- |
| M1 |
7.100 |
| K1 |
15.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2018-08-08T11:54:29.952000Z |
| Discovery magnitude (MPC) |
22.40 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2009-04-15.0000000 |
| e |
0.15350456 |
| q (au) |
3.803759 |
| a (au) |
4.493537 |
| i (deg) |
9.518532 |
| Ω (om, deg) |
325.860084 |
| ω (w, deg) |
27.455141 |
| M (ma, deg) |
359.323198 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.453 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.453 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.509 |
| 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) |
| 2026-09-20 00:00 |
17:17:18.34 |
-30:34:35.8 |
HIP 84611 |
12.80 |
| 2026-09-20 12:00 |
17:17:37.33 |
-30:33:45.8 |
HIP 84611 |
12.53 |
| 2026-09-21 00:00 |
17:17:56.52 |
-30:32:56.0 |
HIP 84611 |
13.60 |
| 2026-09-21 12:00 |
17:18:15.91 |
-30:32:06.6 |
HIP 84611 |
15.78 |
| 2026-09-22 00:00 |
17:18:35.49 |
-30:31:17.4 |
HIP 84611 |
18.70 |
| 2026-09-22 12:00 |
17:18:55.27 |
-30:30:28.5 |
HIP 84806 |
14.81 |
| 2026-09-23 00:00 |
17:19:15.25 |
-30:29:39.9 |
HIP 84806 |
10.49 |
| 2026-09-23 12:00 |
17:19:35.42 |
-30:28:51.5 |
HIP 84806 |
6.22 |
| 2026-09-24 00:00 |
17:19:55.78 |
-30:28:03.4 |
HIP 84806 |
2.51 |
| 2026-09-24 12:00 |
17:20:16.33 |
-30:27:15.6 |
HIP 84806 |
3.75 |
| 2026-09-25 00:00 |
17:20:37.08 |
-30:26:28.0 |
HIP 84806 |
7.94 |
| 2026-09-25 12:00 |
17:20:58.01 |
-30:25:40.7 |
HIP 84806 |
12.42 |
| 2026-09-26 00:00 |
17:21:19.13 |
-30:24:53.6 |
HIP 84982 |
11.96 |
| 2026-09-26 12:00 |
17:21:40.44 |
-30:24:06.7 |
HIP 84982 |
8.59 |
| 2026-09-27 00:00 |
17:22:01.93 |
-30:23:20.1 |
HIP 84982 |
6.92 |
| 2026-09-27 12:00 |
17:22:23.61 |
-30:22:33.7 |
HIP 84982 |
8.14 |
| 2026-09-28 00:00 |
17:22:45.47 |
-30:21:47.6 |
HIP 84999 |
10.57 |
| 2026-09-28 12:00 |
17:23:07.51 |
-30:21:01.7 |
HIP 84999 |
12.78 |
| 2026-09-29 00:00 |
17:23:29.74 |
-30:20:15.9 |
HIP 84999 |
16.21 |
| 2026-09-29 12:00 |
17:23:52.14 |
-30:19:30.4 |
HIP 84999 |
20.27 |
| 2026-09-30 00:00 |
17:24:14.73 |
-30:18:45.1 |
HIP 84999 |
24.67 |
| 2026-09-30 12:00 |
17:24:37.49 |
-30:18:00.0 |
HIP 85171 |
26.06 |
| 2026-10-01 00:00 |
17:25:00.43 |
-30:17:15.1 |
HIP 85171 |
26.53 |
| 2026-10-01 12:00 |
17:25:23.55 |
-30:16:30.4 |
HIP 85171 |
27.94 |
| 2026-10-02 00:00 |
17:25:46.84 |
-30:15:45.9 |
HIP 85413 |
26.92 |
| 2026-10-02 12:00 |
17:26:10.30 |
-30:15:01.5 |
HIP 85413 |
23.05 |
| 2026-10-03 00:00 |
17:26:33.94 |
-30:14:17.4 |
HIP 85413 |
19.76 |
| 2026-10-03 12:00 |
17:26:57.76 |
-30:13:33.4 |
HIP 85413 |
17.39 |
| 2026-10-04 00:00 |
17:27:21.74 |
-30:12:49.5 |
HIP 85413 |
16.39 |
| 2026-10-04 12:00 |
17:27:45.90 |
-30:12:05.8 |
HIP 85413 |
17.05 |
| 2026-10-05 00:00 |
17:28:10.22 |
-30:11:22.3 |
HIP 85413 |
19.21 |
| 2026-10-05 12:00 |
17:28:34.71 |
-30:10:38.9 |
HIP 85413 |
22.48 |
| 2026-10-06 00:00 |
17:28:59.38 |
-30:09:55.7 |
HIP 85413 |
26.48 |
| 2026-10-06 12:00 |
17:29:24.20 |
-30:09:12.6 |
HIP 85739 |
26.35 |
| 2026-10-07 00:00 |
17:29:49.20 |
-30:08:29.6 |
HIP 85739 |
21.81 |
| 2026-10-07 12:00 |
17:30:14.36 |
-30:07:46.8 |
HIP 85739 |
17.75 |
| 2026-10-08 00:00 |
17:30:39.68 |
-30:07:04.1 |
HIP 85739 |
14.63 |
| 2026-10-08 12:00 |
17:31:05.17 |
-30:06:21.5 |
HIP 85770 |
10.28 |
| 2026-10-09 00:00 |
17:31:30.82 |
-30:05:39.0 |
HIP 85770 |
7.63 |
| 2026-10-09 12:00 |
17:31:56.62 |
-30:04:56.6 |
HIP 85770 |
8.59 |
| 2026-10-10 00:00 |
17:32:22.59 |
-30:04:14.3 |
HIP 85770 |
12.39 |
| 2026-10-10 12:00 |
17:32:48.72 |
-30:03:32.1 |
HIP 85770 |
17.28 |
| 2026-10-11 00:00 |
17:33:15.00 |
-30:02:50.0 |
HIP 85770 |
22.59 |