| 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) |
| 2026-07-29 00:00 |
17:06:05.88 |
-32:35:45.5 |
HIP 83653 |
4.77 |
| 2026-07-29 12:00 |
17:05:58.65 |
-32:34:23.1 |
HIP 83653 |
2.73 |
| 2026-07-30 00:00 |
17:05:51.67 |
-32:33:00.7 |
HIP 83653 |
0.80 |
| 2026-07-30 12:00 |
17:05:44.95 |
-32:31:38.3 |
HIP 83653 |
1.33 |
| 2026-07-31 00:00 |
17:05:38.50 |
-32:30:16.0 |
HIP 83653 |
3.22 |
| 2026-07-31 12:00 |
17:05:32.30 |
-32:28:53.7 |
HIP 83653 |
5.10 |
| 2026-08-01 00:00 |
17:05:26.37 |
-32:27:31.5 |
HIP 83653 |
6.95 |
| 2026-08-01 12:00 |
17:05:20.70 |
-32:26:09.4 |
HIP 83653 |
8.76 |
| 2026-08-02 00:00 |
17:05:15.30 |
-32:24:47.4 |
HIP 83653 |
10.53 |
| 2026-08-02 12:00 |
17:05:10.15 |
-32:23:25.5 |
HIP 83653 |
12.26 |
| 2026-08-03 00:00 |
17:05:05.28 |
-32:22:03.7 |
HIP 83653 |
13.96 |
| 2026-08-03 12:00 |
17:05:00.67 |
-32:20:42.0 |
HIP 83653 |
15.62 |
| 2026-08-04 00:00 |
17:04:56.32 |
-32:19:20.4 |
HIP 83653 |
17.25 |
| 2026-08-04 12:00 |
17:04:52.24 |
-32:17:59.0 |
HIP 83653 |
18.84 |
| 2026-08-05 00:00 |
17:04:48.43 |
-32:16:37.7 |
HIP 83653 |
20.39 |
| 2026-08-05 12:00 |
17:04:44.88 |
-32:15:16.6 |
HIP 83653 |
21.91 |
| 2026-08-06 00:00 |
17:04:41.60 |
-32:13:55.7 |
HIP 83653 |
23.40 |
| 2026-08-06 12:00 |
17:04:38.58 |
-32:12:34.9 |
HIP 83668 |
23.53 |
| 2026-08-07 00:00 |
17:04:35.84 |
-32:11:14.3 |
HIP 83668 |
23.14 |
| 2026-08-07 12:00 |
17:04:33.36 |
-32:09:53.9 |
HIP 83668 |
22.79 |
| 2026-08-08 00:00 |
17:04:31.15 |
-32:08:33.7 |
HIP 83668 |
22.47 |
| 2026-08-08 12:00 |
17:04:29.21 |
-32:07:13.8 |
HIP 83668 |
22.20 |
| 2026-08-09 00:00 |
17:04:27.54 |
-32:05:54.0 |
HIP 83668 |
21.95 |
| 2026-08-09 12:00 |
17:04:26.14 |
-32:04:34.5 |
HIP 83668 |
21.74 |
| 2026-08-10 00:00 |
17:04:25.01 |
-32:03:15.3 |
HIP 83668 |
21.56 |
| 2026-08-10 12:00 |
17:04:24.15 |
-32:01:56.2 |
HIP 83668 |
21.41 |
| 2026-08-11 00:00 |
17:04:23.56 |
-32:00:37.5 |
HIP 83668 |
21.28 |
| 2026-08-11 12:00 |
17:04:23.23 |
-31:59:18.9 |
HIP 83668 |
21.18 |
| 2026-08-12 00:00 |
17:04:23.18 |
-31:58:00.7 |
HIP 83668 |
21.11 |
| 2026-08-12 12:00 |
17:04:23.40 |
-31:56:42.7 |
HIP 83668 |
21.05 |
| 2026-08-13 00:00 |
17:04:23.89 |
-31:55:25.1 |
HIP 83668 |
21.02 |
| 2026-08-13 12:00 |
17:04:24.65 |
-31:54:07.7 |
HIP 83668 |
21.01 |
| 2026-08-14 00:00 |
17:04:25.67 |
-31:52:50.6 |
HIP 83668 |
21.02 |
| 2026-08-14 12:00 |
17:04:26.97 |
-31:51:33.8 |
HIP 83448 |
20.76 |
| 2026-08-15 00:00 |
17:04:28.53 |
-31:50:17.3 |
HIP 83448 |
20.13 |
| 2026-08-15 12:00 |
17:04:30.37 |
-31:49:01.1 |
HIP 83448 |
19.61 |
| 2026-08-16 00:00 |
17:04:32.47 |
-31:47:45.3 |
HIP 83448 |
19.23 |
| 2026-08-16 12:00 |
17:04:34.84 |
-31:46:29.8 |
HIP 83448 |
18.98 |
| 2026-08-17 00:00 |
17:04:37.48 |
-31:45:14.6 |
HIP 83448 |
18.88 |
| 2026-08-17 12:00 |
17:04:40.38 |
-31:43:59.7 |
HIP 83448 |
18.93 |
| 2026-08-18 00:00 |
17:04:43.55 |
-31:42:45.2 |
HIP 83448 |
19.14 |
| 2026-08-18 12:00 |
17:04:46.98 |
-31:41:31.0 |
HIP 83581 |
19.26 |
| 2026-08-19 00:00 |
17:04:50.68 |
-31:40:17.2 |
HIP 83581 |
17.97 |