| 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) |
| 2026-03-26 00:00 |
12:33:58.64 |
-02:03:43.5 |
HIP 61245 |
19.55 |
| 2026-03-26 12:00 |
12:33:49.30 |
-02:02:31.2 |
HIP 61245 |
18.90 |
| 2026-03-27 00:00 |
12:33:39.96 |
-02:01:18.9 |
HIP 61245 |
18.60 |
| 2026-03-27 12:00 |
12:33:30.60 |
-02:00:06.5 |
HIP 61245 |
18.66 |
| 2026-03-28 00:00 |
12:33:21.24 |
-01:58:54.1 |
HIP 61245 |
19.10 |
| 2026-03-28 12:00 |
12:33:11.86 |
-01:57:41.8 |
HIP 61245 |
19.87 |
| 2026-03-29 00:00 |
12:33:02.49 |
-01:56:29.4 |
HIP 61173 |
17.69 |
| 2026-03-29 12:00 |
12:32:53.11 |
-01:55:17.0 |
HIP 61173 |
15.09 |
| 2026-03-30 00:00 |
12:32:43.72 |
-01:54:04.7 |
HIP 61173 |
12.49 |
| 2026-03-30 12:00 |
12:32:34.33 |
-01:52:52.4 |
HIP 61173 |
9.91 |
| 2026-03-31 00:00 |
12:32:24.95 |
-01:51:40.1 |
HIP 61173 |
7.38 |
| 2026-03-31 12:00 |
12:32:15.56 |
-01:50:27.8 |
HIP 61173 |
4.96 |
| 2026-04-01 00:00 |
12:32:06.17 |
-01:49:15.6 |
HIP 61173 |
2.94 |
| 2026-04-01 12:00 |
12:31:56.78 |
-01:48:03.5 |
HIP 61173 |
2.57 |
| 2026-04-02 00:00 |
12:31:47.40 |
-01:46:51.4 |
HIP 61173 |
4.30 |
| 2026-04-02 12:00 |
12:31:38.02 |
-01:45:39.3 |
HIP 61173 |
6.65 |
| 2026-04-03 00:00 |
12:31:28.64 |
-01:44:27.4 |
HIP 61173 |
9.15 |
| 2026-04-03 12:00 |
12:31:19.27 |
-01:43:15.5 |
HIP 61173 |
11.71 |
| 2026-04-04 00:00 |
12:31:09.91 |
-01:42:03.7 |
HIP 61173 |
14.29 |
| 2026-04-04 12:00 |
12:31:00.56 |
-01:40:52.0 |
HIP 61173 |
16.88 |
| 2026-04-05 00:00 |
12:30:51.21 |
-01:39:40.4 |
HIP 61018 |
18.64 |
| 2026-04-05 12:00 |
12:30:41.88 |
-01:38:28.9 |
HIP 61018 |
18.91 |
| 2026-04-06 00:00 |
12:30:32.55 |
-01:37:17.5 |
HIP 61018 |
19.53 |
| 2026-04-06 12:00 |
12:30:23.24 |
-01:36:06.3 |
HIP 61018 |
20.46 |
| 2026-04-07 00:00 |
12:30:13.94 |
-01:34:55.2 |
HIP 61018 |
21.67 |
| 2026-04-07 12:00 |
12:30:04.66 |
-01:33:44.2 |
HIP 60938 |
22.34 |
| 2026-04-08 00:00 |
12:29:55.39 |
-01:32:33.3 |
HIP 60938 |
20.27 |
| 2026-04-08 12:00 |
12:29:46.14 |
-01:31:22.6 |
HIP 60938 |
18.34 |
| 2026-04-09 00:00 |
12:29:36.91 |
-01:30:12.1 |
HIP 60938 |
16.59 |
| 2026-04-09 12:00 |
12:29:27.70 |
-01:29:01.7 |
HIP 60938 |
15.10 |
| 2026-04-10 00:00 |
12:29:18.50 |
-01:27:51.5 |
HIP 60938 |
13.92 |
| 2026-04-10 12:00 |
12:29:09.33 |
-01:26:41.5 |
HIP 60938 |
13.16 |
| 2026-04-11 00:00 |
12:29:00.18 |
-01:25:31.7 |
HIP 60938 |
12.87 |
| 2026-04-11 12:00 |
12:28:51.05 |
-01:24:22.1 |
HIP 60938 |
13.09 |
| 2026-04-12 00:00 |
12:28:41.95 |
-01:23:12.6 |
HIP 60938 |
13.79 |
| 2026-04-12 12:00 |
12:28:32.87 |
-01:22:03.4 |
HIP 60938 |
14.89 |
| 2026-04-13 00:00 |
12:28:23.82 |
-01:20:54.4 |
HIP 60938 |
16.31 |
| 2026-04-13 12:00 |
12:28:14.80 |
-01:19:45.7 |
HIP 60938 |
17.98 |
| 2026-04-14 00:00 |
12:28:05.80 |
-01:18:37.1 |
HIP 60938 |
19.82 |
| 2026-04-14 12:00 |
12:27:56.84 |
-01:17:28.8 |
HIP 60938 |
21.80 |
| 2026-04-15 00:00 |
12:27:47.90 |
-01:16:20.7 |
HIP 60938 |
23.87 |
| 2026-04-15 12:00 |
12:27:39.00 |
-01:15:12.9 |
HIP 60938 |
26.00 |
| 2026-04-16 00:00 |
12:27:30.13 |
-01:14:05.4 |
HIP 60648 |
25.83 |