| Parameter |
Value |
| Designation |
465P/Hill |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2008-08-18T17:57:24.065280Z |
| Orbit solution date (soln_date, UTC) |
2024-07-13T19:12:23Z |
| Obs used |
706 |
| NEO |
- |
| M1 |
6.900 |
| K1 |
25.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-07-24.0000000 |
| e |
0.61380782 |
| q (au) |
2.322142 |
| a (au) |
6.012919 |
| i (deg) |
25.854343 |
| Ω (om, deg) |
217.938849 |
| ω (w, deg) |
141.510289 |
| M (ma, deg) |
71.475305 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.276 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.276 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| δ90 |
10.000 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2023-06-08 |
2024-01-05 |
+9.7551 |
-4.150 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
08:35:59.30 |
-06:11:10.0 |
HIP 42292 |
26.62 |
| 2026-06-01 12:00 |
08:36:12.05 |
-06:10:34.9 |
HIP 42292 |
24.70 |
| 2026-06-02 00:00 |
08:36:24.88 |
-06:10:00.7 |
HIP 42292 |
23.06 |
| 2026-06-02 12:00 |
08:36:37.79 |
-06:09:27.3 |
HIP 42292 |
21.76 |
| 2026-06-03 00:00 |
08:36:50.78 |
-06:08:54.8 |
HIP 42292 |
20.86 |
| 2026-06-03 12:00 |
08:37:03.83 |
-06:08:23.2 |
HIP 42292 |
20.44 |
| 2026-06-04 00:00 |
08:37:16.97 |
-06:07:52.5 |
HIP 42292 |
20.52 |
| 2026-06-04 12:00 |
08:37:30.17 |
-06:07:22.7 |
HIP 42292 |
21.12 |
| 2026-06-05 00:00 |
08:37:43.45 |
-06:06:53.7 |
HIP 42408 |
19.22 |
| 2026-06-05 12:00 |
08:37:56.80 |
-06:06:25.7 |
HIP 42408 |
16.20 |
| 2026-06-06 00:00 |
08:38:10.22 |
-06:05:58.5 |
HIP 42408 |
13.33 |
| 2026-06-06 12:00 |
08:38:23.71 |
-06:05:32.2 |
HIP 42408 |
10.76 |
| 2026-06-07 00:00 |
08:38:37.28 |
-06:05:06.8 |
HIP 42408 |
8.77 |
| 2026-06-07 12:00 |
08:38:50.91 |
-06:04:42.2 |
HIP 42408 |
7.84 |
| 2026-06-08 00:00 |
08:39:04.61 |
-06:04:18.5 |
HIP 42408 |
8.34 |
| 2026-06-08 12:00 |
08:39:18.38 |
-06:03:55.8 |
HIP 42408 |
10.08 |
| 2026-06-09 00:00 |
08:39:32.21 |
-06:03:33.9 |
HIP 42408 |
12.57 |
| 2026-06-09 12:00 |
08:39:46.12 |
-06:03:12.8 |
HIP 42408 |
15.46 |
| 2026-06-10 00:00 |
08:40:00.09 |
-06:02:52.7 |
HIP 42408 |
18.57 |
| 2026-06-10 12:00 |
08:40:14.12 |
-06:02:33.4 |
HIP 42408 |
21.82 |
| 2026-06-11 00:00 |
08:40:28.22 |
-06:02:15.1 |
HIP 42408 |
25.15 |
| 2026-06-11 12:00 |
08:40:42.39 |
-06:01:57.6 |
HIP 42408 |
28.55 |
| 2026-06-12 00:00 |
08:40:56.62 |
-06:01:40.9 |
HIP 42674 |
28.38 |
| 2026-06-12 12:00 |
08:41:10.91 |
-06:01:25.2 |
HIP 42674 |
26.64 |
| 2026-06-13 00:00 |
08:41:25.26 |
-06:01:10.3 |
HIP 42674 |
25.31 |
| 2026-06-13 12:00 |
08:41:39.67 |
-06:00:56.4 |
HIP 42674 |
24.44 |
| 2026-06-14 00:00 |
08:41:54.15 |
-06:00:43.3 |
HIP 42674 |
24.10 |
| 2026-06-14 12:00 |
08:42:08.69 |
-06:00:31.0 |
HIP 42674 |
24.31 |
| 2026-06-15 00:00 |
08:42:23.28 |
-06:00:19.7 |
HIP 42674 |
25.06 |
| 2026-06-15 12:00 |
08:42:37.94 |
-06:00:09.2 |
HIP 42674 |
26.33 |
| 2026-06-16 00:00 |
08:42:52.65 |
-05:59:59.6 |
HIP 42674 |
28.03 |
| 2026-06-16 12:00 |
08:43:07.42 |
-05:59:50.9 |
HIP 42674 |
30.11 |
| 2026-06-17 00:00 |
08:43:22.24 |
-05:59:43.0 |
HIP 42674 |
32.49 |
| 2026-06-17 12:00 |
08:43:37.12 |
-05:59:36.0 |
HIP 42674 |
35.11 |
| 2026-06-18 00:00 |
08:43:52.06 |
-05:59:29.9 |
HIP 42674 |
37.94 |
| 2026-06-18 12:00 |
08:44:07.05 |
-05:59:24.7 |
HIP 42674 |
40.93 |
| 2026-06-19 00:00 |
08:44:22.09 |
-05:59:20.3 |
HIP 43019 |
41.03 |
| 2026-06-19 12:00 |
08:44:37.18 |
-05:59:16.7 |
HIP 43019 |
38.97 |
| 2026-06-20 00:00 |
08:44:52.33 |
-05:59:14.1 |
HIP 43019 |
37.16 |
| 2026-06-20 12:00 |
08:45:07.53 |
-05:59:12.3 |
HIP 43019 |
35.64 |
| 2026-06-21 00:00 |
08:45:22.78 |
-05:59:11.3 |
HIP 43019 |
34.45 |
| 2026-06-21 12:00 |
08:45:38.07 |
-05:59:11.2 |
HIP 43019 |
33.63 |
| 2026-06-22 00:00 |
08:45:53.42 |
-05:59:12.0 |
HIP 43019 |
33.21 |