| 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) |
| 2026-09-20 00:00 |
12:41:30.76 |
-02:08:36.9 |
HIP 62036 |
22.30 |
| 2026-09-20 12:00 |
12:41:43.12 |
-02:09:46.5 |
HIP 62036 |
19.01 |
| 2026-09-21 00:00 |
12:41:55.50 |
-02:10:56.1 |
HIP 62036 |
15.72 |
| 2026-09-21 12:00 |
12:42:07.90 |
-02:12:05.8 |
HIP 62036 |
12.43 |
| 2026-09-22 00:00 |
12:42:20.32 |
-02:13:15.6 |
HIP 62036 |
9.14 |
| 2026-09-22 12:00 |
12:42:32.77 |
-02:14:25.4 |
HIP 62036 |
5.89 |
| 2026-09-23 00:00 |
12:42:45.23 |
-02:15:35.3 |
HIP 62036 |
2.79 |
| 2026-09-23 12:00 |
12:42:57.71 |
-02:16:45.3 |
HIP 62036 |
1.72 |
| 2026-09-24 00:00 |
12:43:10.20 |
-02:17:55.3 |
HIP 62036 |
4.51 |
| 2026-09-24 12:00 |
12:43:22.72 |
-02:19:05.3 |
HIP 62036 |
7.74 |
| 2026-09-25 00:00 |
12:43:35.25 |
-02:20:15.4 |
HIP 62036 |
11.04 |
| 2026-09-25 12:00 |
12:43:47.80 |
-02:21:25.5 |
HIP 62036 |
14.37 |
| 2026-09-26 00:00 |
12:44:00.36 |
-02:22:35.7 |
HIP 62036 |
17.70 |
| 2026-09-26 12:00 |
12:44:12.95 |
-02:23:45.9 |
HIP 62185 |
19.91 |
| 2026-09-27 00:00 |
12:44:25.54 |
-02:24:56.1 |
HIP 62185 |
17.92 |
| 2026-09-27 12:00 |
12:44:38.16 |
-02:26:06.3 |
HIP 62185 |
16.37 |
| 2026-09-28 00:00 |
12:44:50.78 |
-02:27:16.6 |
HIP 62185 |
15.41 |
| 2026-09-28 12:00 |
12:45:03.42 |
-02:28:26.9 |
HIP 62185 |
15.16 |
| 2026-09-29 00:00 |
12:45:16.08 |
-02:29:37.2 |
HIP 62185 |
15.65 |
| 2026-09-29 12:00 |
12:45:28.75 |
-02:30:47.5 |
HIP 62185 |
16.81 |
| 2026-09-30 00:00 |
12:45:41.43 |
-02:31:57.8 |
HIP 62185 |
18.53 |
| 2026-09-30 12:00 |
12:45:54.12 |
-02:33:08.2 |
HIP 62185 |
20.66 |
| 2026-10-01 00:00 |
12:46:06.82 |
-02:34:18.5 |
HIP 62185 |
23.09 |
| 2026-10-01 12:00 |
12:46:19.54 |
-02:35:28.9 |
HIP 62185 |
25.75 |
| 2026-10-02 00:00 |
12:46:32.27 |
-02:36:39.2 |
HIP 62185 |
28.56 |
| 2026-10-02 12:00 |
12:46:45.01 |
-02:37:49.6 |
HIP 62185 |
31.48 |
| 2026-10-03 00:00 |
12:46:57.76 |
-02:39:00.0 |
HIP 62380 |
33.91 |
| 2026-10-03 12:00 |
12:47:10.51 |
-02:40:10.2 |
HIP 62380 |
35.09 |
| 2026-10-04 00:00 |
12:47:23.28 |
-02:41:20.5 |
HIP 62380 |
36.55 |
| 2026-10-04 12:00 |
12:47:36.06 |
-02:42:30.8 |
HIP 62380 |
38.26 |
| 2026-10-05 00:00 |
12:47:48.84 |
-02:43:41.1 |
HIP 62602 |
38.67 |
| 2026-10-05 12:00 |
12:48:01.63 |
-02:44:51.3 |
HIP 62602 |
37.25 |
| 2026-10-06 00:00 |
12:48:14.43 |
-02:46:01.5 |
HIP 62602 |
36.10 |
| 2026-10-06 12:00 |
12:48:27.23 |
-02:47:11.7 |
HIP 62602 |
35.23 |
| 2026-10-07 00:00 |
12:48:40.04 |
-02:48:21.8 |
HIP 62602 |
34.68 |
| 2026-10-07 12:00 |
12:48:52.86 |
-02:49:31.9 |
HIP 62602 |
34.46 |
| 2026-10-08 00:00 |
12:49:05.68 |
-02:50:41.9 |
HIP 62733 |
33.26 |
| 2026-10-08 12:00 |
12:49:18.50 |
-02:51:51.9 |
HIP 62733 |
29.97 |
| 2026-10-09 00:00 |
12:49:31.33 |
-02:53:01.8 |
HIP 62733 |
26.71 |
| 2026-10-09 12:00 |
12:49:44.16 |
-02:54:11.7 |
HIP 62733 |
23.49 |
| 2026-10-10 00:00 |
12:49:57.00 |
-02:55:21.5 |
HIP 62733 |
20.33 |
| 2026-10-10 12:00 |
12:50:09.83 |
-02:56:31.2 |
HIP 62733 |
17.26 |
| 2026-10-11 00:00 |
12:50:22.67 |
-02:57:40.9 |
HIP 62733 |
14.35 |