| 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
$$
M_a = (13.999 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.999 |
| n |
2.000 |
| gf |
0.970 |
| gb |
-0.965 |
| k |
1.000 |
| δ90 |
8.163 |
| 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) |
| 2026-05-12 00:00 |
12:20:57.77 |
-00:24:04.5 |
HIP 60280 |
17.70 |
| 2026-05-12 12:00 |
12:20:51.93 |
-00:23:19.0 |
HIP 60164 |
17.28 |
| 2026-05-13 00:00 |
12:20:46.16 |
-00:22:34.0 |
HIP 60164 |
15.90 |
| 2026-05-13 12:00 |
12:20:40.47 |
-00:21:49.6 |
HIP 60164 |
14.59 |
| 2026-05-14 00:00 |
12:20:34.85 |
-00:21:05.8 |
HIP 60164 |
13.36 |
| 2026-05-14 12:00 |
12:20:29.32 |
-00:20:22.5 |
HIP 60164 |
12.22 |
| 2026-05-15 00:00 |
12:20:23.86 |
-00:19:39.7 |
HIP 60164 |
11.20 |
| 2026-05-15 12:00 |
12:20:18.48 |
-00:18:57.5 |
HIP 60164 |
10.32 |
| 2026-05-16 00:00 |
12:20:13.19 |
-00:18:15.9 |
HIP 60164 |
9.60 |
| 2026-05-16 12:00 |
12:20:07.97 |
-00:17:34.8 |
HIP 60164 |
9.09 |
| 2026-05-17 00:00 |
12:20:02.83 |
-00:16:54.3 |
HIP 60164 |
8.79 |
| 2026-05-17 12:00 |
12:19:57.78 |
-00:16:14.4 |
HIP 60164 |
8.73 |
| 2026-05-18 00:00 |
12:19:52.81 |
-00:15:35.0 |
HIP 60164 |
8.89 |
| 2026-05-18 12:00 |
12:19:47.92 |
-00:14:56.2 |
HIP 60164 |
9.26 |
| 2026-05-19 00:00 |
12:19:43.11 |
-00:14:18.0 |
HIP 60164 |
9.80 |
| 2026-05-19 12:00 |
12:19:38.39 |
-00:13:40.4 |
HIP 60164 |
10.47 |
| 2026-05-20 00:00 |
12:19:33.75 |
-00:13:03.3 |
HIP 60164 |
11.25 |
| 2026-05-20 12:00 |
12:19:29.19 |
-00:12:26.9 |
HIP 60164 |
12.11 |
| 2026-05-21 00:00 |
12:19:24.72 |
-00:11:51.0 |
HIP 60164 |
13.01 |
| 2026-05-21 12:00 |
12:19:20.34 |
-00:11:15.7 |
HIP 60164 |
13.96 |
| 2026-05-22 00:00 |
12:19:16.04 |
-00:10:41.0 |
HIP 60164 |
14.93 |
| 2026-05-22 12:00 |
12:19:11.83 |
-00:10:06.9 |
HIP 60164 |
15.91 |
| 2026-05-23 00:00 |
12:19:07.70 |
-00:09:33.4 |
HIP 60164 |
16.90 |
| 2026-05-23 12:00 |
12:19:03.66 |
-00:09:00.5 |
HIP 60164 |
17.89 |
| 2026-05-24 00:00 |
12:18:59.70 |
-00:08:28.2 |
HIP 60164 |
18.88 |
| 2026-05-24 12:00 |
12:18:55.83 |
-00:07:56.5 |
HIP 60164 |
19.86 |
| 2026-05-25 00:00 |
12:18:52.05 |
-00:07:25.4 |
HIP 60164 |
20.83 |
| 2026-05-25 12:00 |
12:18:48.36 |
-00:06:54.9 |
HIP 60164 |
21.78 |
| 2026-05-26 00:00 |
12:18:44.75 |
-00:06:25.0 |
HIP 60164 |
22.73 |
| 2026-05-26 12:00 |
12:18:41.24 |
-00:05:55.7 |
HIP 60164 |
23.65 |
| 2026-05-27 00:00 |
12:18:37.80 |
-00:05:27.0 |
HIP 60164 |
24.56 |
| 2026-05-27 12:00 |
12:18:34.46 |
-00:04:58.9 |
HIP 59906 |
25.19 |
| 2026-05-28 00:00 |
12:18:31.21 |
-00:04:31.4 |
HIP 59906 |
24.27 |
| 2026-05-28 12:00 |
12:18:28.04 |
-00:04:04.5 |
HIP 59906 |
23.37 |
| 2026-05-29 00:00 |
12:18:24.97 |
-00:03:38.2 |
HIP 59906 |
22.50 |
| 2026-05-29 12:00 |
12:18:21.98 |
-00:03:12.6 |
HIP 59906 |
21.65 |
| 2026-05-30 00:00 |
12:18:19.08 |
-00:02:47.5 |
HIP 59906 |
20.83 |
| 2026-05-30 12:00 |
12:18:16.28 |
-00:02:23.0 |
HIP 59906 |
20.03 |
| 2026-05-31 00:00 |
12:18:13.56 |
-00:01:59.2 |
HIP 59906 |
19.26 |
| 2026-05-31 12:00 |
12:18:10.93 |
-00:01:36.0 |
HIP 59906 |
18.51 |
| 2026-06-01 00:00 |
12:18:08.39 |
-00:01:13.3 |
HIP 59906 |
17.78 |
| 2026-06-01 12:00 |
12:18:05.94 |
-00:00:51.3 |
HIP 59906 |
17.08 |
| 2026-06-02 00:00 |
12:18:03.58 |
-00:00:30.0 |
HIP 59906 |
16.41 |