| Parameter |
Value |
| Designation |
P/2009 Q5 (McNaught) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2009-09-08T13:50:29.091840Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:34Z |
| Obs used |
331 |
| NEO |
- |
| M1 |
13.100 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2009-10-09.0000000 |
| e |
0.60905285 |
| q (au) |
2.918512 |
| a (au) |
7.465233 |
| i (deg) |
40.904822 |
| Ω (om, deg) |
160.139864 |
| ω (w, deg) |
209.274918 |
| M (ma, deg) |
1.470093 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.634 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.634 |
| n |
2.000 |
| gf |
0.974 |
| gb |
-1.000 |
| k |
0.999 |
| δ90 |
9.888 |
| 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) |
| 2026-09-20 00:00 |
15:46:02.30 |
+18:46:55.5 |
HIP 77351 |
19.86 |
| 2026-09-20 12:00 |
15:46:13.58 |
+18:44:34.4 |
HIP 77351 |
17.63 |
| 2026-09-21 00:00 |
15:46:24.97 |
+18:42:13.6 |
HIP 77351 |
15.87 |
| 2026-09-21 12:00 |
15:46:36.45 |
+18:39:53.2 |
HIP 77351 |
14.75 |
| 2026-09-22 00:00 |
15:46:48.02 |
+18:37:33.2 |
HIP 77351 |
14.44 |
| 2026-09-22 12:00 |
15:46:59.70 |
+18:35:13.5 |
HIP 77351 |
14.99 |
| 2026-09-23 00:00 |
15:47:11.47 |
+18:32:54.1 |
HIP 77351 |
16.34 |
| 2026-09-23 12:00 |
15:47:23.34 |
+18:30:35.2 |
HIP 77351 |
18.31 |
| 2026-09-24 00:00 |
15:47:35.30 |
+18:28:16.6 |
HIP 77351 |
20.73 |
| 2026-09-24 12:00 |
15:47:47.35 |
+18:25:58.4 |
HIP 77450 |
22.10 |
| 2026-09-25 00:00 |
15:47:59.50 |
+18:23:40.6 |
HIP 77450 |
18.54 |
| 2026-09-25 12:00 |
15:48:11.75 |
+18:21:23.3 |
HIP 77450 |
15.04 |
| 2026-09-26 00:00 |
15:48:24.08 |
+18:19:06.3 |
HIP 77450 |
11.65 |
| 2026-09-26 12:00 |
15:48:36.51 |
+18:16:49.7 |
HIP 77450 |
8.53 |
| 2026-09-27 00:00 |
15:48:49.03 |
+18:14:33.6 |
HIP 77450 |
6.15 |
| 2026-09-27 12:00 |
15:49:01.65 |
+18:12:17.9 |
HIP 77450 |
5.58 |
| 2026-09-28 00:00 |
15:49:14.35 |
+18:10:02.6 |
HIP 77450 |
7.28 |
| 2026-09-28 12:00 |
15:49:27.14 |
+18:07:47.7 |
HIP 77450 |
10.18 |
| 2026-09-29 00:00 |
15:49:40.03 |
+18:05:33.3 |
HIP 77450 |
13.54 |
| 2026-09-29 12:00 |
15:49:53.00 |
+18:03:19.4 |
HIP 77450 |
17.10 |
| 2026-09-30 00:00 |
15:50:06.06 |
+18:01:05.9 |
HIP 77450 |
20.77 |
| 2026-09-30 12:00 |
15:50:19.21 |
+17:58:52.8 |
HIP 77450 |
24.50 |
| 2026-10-01 00:00 |
15:50:32.45 |
+17:56:40.2 |
HIP 77587 |
25.38 |
| 2026-10-01 12:00 |
15:50:45.78 |
+17:54:28.1 |
HIP 77587 |
23.57 |
| 2026-10-02 00:00 |
15:50:59.19 |
+17:52:16.5 |
HIP 77587 |
22.30 |
| 2026-10-02 12:00 |
15:51:12.69 |
+17:50:05.3 |
HIP 77587 |
21.68 |
| 2026-10-03 00:00 |
15:51:26.28 |
+17:47:54.7 |
HIP 77587 |
21.77 |
| 2026-10-03 12:00 |
15:51:39.95 |
+17:45:44.5 |
HIP 77773 |
21.18 |
| 2026-10-04 00:00 |
15:51:53.71 |
+17:43:34.8 |
HIP 77773 |
17.26 |
| 2026-10-04 12:00 |
15:52:07.55 |
+17:41:25.7 |
HIP 77773 |
13.33 |
| 2026-10-05 00:00 |
15:52:21.48 |
+17:39:17.0 |
HIP 77773 |
9.39 |
| 2026-10-05 12:00 |
15:52:35.49 |
+17:37:08.9 |
HIP 77773 |
5.47 |
| 2026-10-06 00:00 |
15:52:49.58 |
+17:35:01.3 |
HIP 77773 |
1.72 |
| 2026-10-06 12:00 |
15:53:03.76 |
+17:32:54.3 |
HIP 77773 |
2.78 |
| 2026-10-07 00:00 |
15:53:18.02 |
+17:30:47.8 |
HIP 77773 |
6.67 |
| 2026-10-07 12:00 |
15:53:32.36 |
+17:28:41.8 |
HIP 77849 |
9.02 |
| 2026-10-08 00:00 |
15:53:46.78 |
+17:26:36.4 |
HIP 77849 |
10.38 |
| 2026-10-08 12:00 |
15:54:01.28 |
+17:24:31.6 |
HIP 77849 |
12.89 |
| 2026-10-09 00:00 |
15:54:15.87 |
+17:22:27.3 |
HIP 77849 |
16.04 |
| 2026-10-09 12:00 |
15:54:30.53 |
+17:20:23.6 |
HIP 77849 |
19.53 |
| 2026-10-10 00:00 |
15:54:45.27 |
+17:18:20.5 |
HIP 77875 |
20.64 |
| 2026-10-10 12:00 |
15:55:00.08 |
+17:16:18.0 |
HIP 77875 |
20.61 |
| 2026-10-11 00:00 |
15:55:14.98 |
+17:14:16.1 |
HIP 77875 |
21.40 |