| Parameter |
Value |
| Designation |
P/2009 O3 (Hill) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2009-05-18T14:30:19.399680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:31Z |
| Obs used |
328 |
| NEO |
- |
| M1 |
15.200 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2009-09-08.0000000 |
| e |
0.68688005 |
| q (au) |
2.449980 |
| a (au) |
7.824412 |
| i (deg) |
16.217527 |
| Ω (om, deg) |
183.763869 |
| ω (w, deg) |
154.552199 |
| M (ma, deg) |
5.061460 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.998 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.998 |
| n |
2.000 |
| gf |
0.973 |
| gb |
-0.965 |
| k |
1.000 |
| δ90 |
8.190 |
| 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 |
12:23:18.89 |
-00:24:16.8 |
HIP 60378 |
11.91 |
| 2026-07-29 12:00 |
12:23:26.33 |
-00:24:59.4 |
HIP 60378 |
13.67 |
| 2026-07-30 00:00 |
12:23:33.85 |
-00:25:42.3 |
HIP 60378 |
15.50 |
| 2026-07-30 12:00 |
12:23:41.43 |
-00:26:25.6 |
HIP 60378 |
17.38 |
| 2026-07-31 00:00 |
12:23:49.07 |
-00:27:09.4 |
HIP 60378 |
19.32 |
| 2026-07-31 12:00 |
12:23:56.79 |
-00:27:53.6 |
HIP 60378 |
21.29 |
| 2026-08-01 00:00 |
12:24:04.57 |
-00:28:38.2 |
HIP 60378 |
23.29 |
| 2026-08-01 12:00 |
12:24:12.43 |
-00:29:23.2 |
HIP 60641 |
25.32 |
| 2026-08-02 00:00 |
12:24:20.34 |
-00:30:08.6 |
HIP 60641 |
24.03 |
| 2026-08-02 12:00 |
12:24:28.33 |
-00:30:54.4 |
HIP 60641 |
22.85 |
| 2026-08-03 00:00 |
12:24:36.37 |
-00:31:40.7 |
HIP 60641 |
21.80 |
| 2026-08-03 12:00 |
12:24:44.49 |
-00:32:27.3 |
HIP 60641 |
20.92 |
| 2026-08-04 00:00 |
12:24:52.67 |
-00:33:14.3 |
HIP 60641 |
20.24 |
| 2026-08-04 12:00 |
12:25:00.91 |
-00:34:01.7 |
HIP 60641 |
19.77 |
| 2026-08-05 00:00 |
12:25:09.22 |
-00:34:49.5 |
HIP 60641 |
19.54 |
| 2026-08-05 12:00 |
12:25:17.60 |
-00:35:37.7 |
HIP 60641 |
19.56 |
| 2026-08-06 00:00 |
12:25:26.03 |
-00:36:26.2 |
HIP 60641 |
19.84 |
| 2026-08-06 12:00 |
12:25:34.53 |
-00:37:15.2 |
HIP 60641 |
20.38 |
| 2026-08-07 00:00 |
12:25:43.10 |
-00:38:04.5 |
HIP 60641 |
21.15 |
| 2026-08-07 12:00 |
12:25:51.72 |
-00:38:54.2 |
HIP 60641 |
22.14 |
| 2026-08-08 00:00 |
12:26:00.41 |
-00:39:44.3 |
HIP 60641 |
23.33 |
| 2026-08-08 12:00 |
12:26:09.16 |
-00:40:34.8 |
HIP 60641 |
24.70 |
| 2026-08-09 00:00 |
12:26:17.97 |
-00:41:25.6 |
HIP 60648 |
26.07 |
| 2026-08-09 12:00 |
12:26:26.84 |
-00:42:16.8 |
HIP 60648 |
25.92 |
| 2026-08-10 00:00 |
12:26:35.78 |
-00:43:08.3 |
HIP 60648 |
25.99 |
| 2026-08-10 12:00 |
12:26:44.77 |
-00:44:00.2 |
HIP 60648 |
26.28 |
| 2026-08-11 00:00 |
12:26:53.82 |
-00:44:52.5 |
HIP 60648 |
26.79 |
| 2026-08-11 12:00 |
12:27:02.93 |
-00:45:45.1 |
HIP 60648 |
27.51 |
| 2026-08-12 00:00 |
12:27:12.11 |
-00:46:38.1 |
HIP 60648 |
28.43 |
| 2026-08-12 12:00 |
12:27:21.34 |
-00:47:31.4 |
HIP 60648 |
29.53 |
| 2026-08-13 00:00 |
12:27:30.62 |
-00:48:25.0 |
HIP 60648 |
30.80 |
| 2026-08-13 12:00 |
12:27:39.97 |
-00:49:19.0 |
HIP 60648 |
32.23 |
| 2026-08-14 00:00 |
12:27:49.37 |
-00:50:13.3 |
HIP 60938 |
33.34 |
| 2026-08-14 12:00 |
12:27:58.83 |
-00:51:08.0 |
HIP 60938 |
31.05 |
| 2026-08-15 00:00 |
12:28:08.35 |
-00:52:02.9 |
HIP 60938 |
28.78 |
| 2026-08-15 12:00 |
12:28:17.92 |
-00:52:58.2 |
HIP 60938 |
26.56 |
| 2026-08-16 00:00 |
12:28:27.54 |
-00:53:53.9 |
HIP 60938 |
24.39 |
| 2026-08-16 12:00 |
12:28:37.22 |
-00:54:49.8 |
HIP 60938 |
22.30 |
| 2026-08-17 00:00 |
12:28:46.96 |
-00:55:46.0 |
HIP 60938 |
20.31 |
| 2026-08-17 12:00 |
12:28:56.74 |
-00:56:42.6 |
HIP 60938 |
18.47 |
| 2026-08-18 00:00 |
12:29:06.58 |
-00:57:39.4 |
HIP 60938 |
16.83 |
| 2026-08-18 12:00 |
12:29:16.48 |
-00:58:36.6 |
HIP 60938 |
15.46 |
| 2026-08-19 00:00 |
12:29:26.42 |
-00:59:34.0 |
HIP 60938 |
14.44 |