| 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) |
| 2026-09-25 00:00 |
09:37:33.73 |
-09:32:11.2 |
HIP 47249 |
8.03 |
| 2026-09-25 12:00 |
09:37:47.47 |
-09:34:06.0 |
HIP 47249 |
8.69 |
| 2026-09-26 00:00 |
09:38:01.15 |
-09:36:01.0 |
HIP 47249 |
10.81 |
| 2026-09-26 12:00 |
09:38:14.76 |
-09:37:56.3 |
HIP 47249 |
13.72 |
| 2026-09-27 00:00 |
09:38:28.31 |
-09:39:51.8 |
HIP 47249 |
17.01 |
| 2026-09-27 12:00 |
09:38:41.80 |
-09:41:47.6 |
HIP 47249 |
20.49 |
| 2026-09-28 00:00 |
09:38:55.22 |
-09:43:43.6 |
HIP 47249 |
24.08 |
| 2026-09-28 12:00 |
09:39:08.57 |
-09:45:39.8 |
HIP 47249 |
27.72 |
| 2026-09-29 00:00 |
09:39:21.86 |
-09:47:36.2 |
HIP 47249 |
31.39 |
| 2026-09-29 12:00 |
09:39:35.08 |
-09:49:32.9 |
HIP 47249 |
35.09 |
| 2026-09-30 00:00 |
09:39:48.23 |
-09:51:29.8 |
HIP 47249 |
38.79 |
| 2026-09-30 12:00 |
09:40:01.31 |
-09:53:26.9 |
HIP 47427 |
40.91 |
| 2026-10-01 00:00 |
09:40:14.32 |
-09:55:24.2 |
HIP 47534 |
39.14 |
| 2026-10-01 12:00 |
09:40:27.27 |
-09:57:21.7 |
HIP 47534 |
35.99 |
| 2026-10-02 00:00 |
09:40:40.14 |
-09:59:19.4 |
HIP 47534 |
32.96 |
| 2026-10-02 12:00 |
09:40:52.94 |
-10:01:17.3 |
HIP 47534 |
30.09 |
| 2026-10-03 00:00 |
09:41:05.67 |
-10:03:15.4 |
HIP 47534 |
27.43 |
| 2026-10-03 12:00 |
09:41:18.33 |
-10:05:13.7 |
HIP 47534 |
25.03 |
| 2026-10-04 00:00 |
09:41:30.92 |
-10:07:12.1 |
HIP 47534 |
22.97 |
| 2026-10-04 12:00 |
09:41:43.43 |
-10:09:10.8 |
HIP 47534 |
21.33 |
| 2026-10-05 00:00 |
09:41:55.87 |
-10:11:09.6 |
HIP 47534 |
20.23 |
| 2026-10-05 12:00 |
09:42:08.23 |
-10:13:08.5 |
HIP 47534 |
19.74 |
| 2026-10-06 00:00 |
09:42:20.52 |
-10:15:07.7 |
HIP 47534 |
19.89 |
| 2026-10-06 12:00 |
09:42:32.73 |
-10:17:06.9 |
HIP 47534 |
20.66 |
| 2026-10-07 00:00 |
09:42:44.86 |
-10:19:06.4 |
HIP 47534 |
21.99 |
| 2026-10-07 12:00 |
09:42:56.92 |
-10:21:05.9 |
HIP 47534 |
23.77 |
| 2026-10-08 00:00 |
09:43:08.90 |
-10:23:05.6 |
HIP 47734 |
25.62 |
| 2026-10-08 12:00 |
09:43:20.80 |
-10:25:05.4 |
HIP 47734 |
26.56 |
| 2026-10-09 00:00 |
09:43:32.62 |
-10:27:05.4 |
HIP 47734 |
27.92 |
| 2026-10-09 12:00 |
09:43:44.36 |
-10:29:05.5 |
HIP 47621 |
28.73 |
| 2026-10-10 00:00 |
09:43:56.02 |
-10:31:05.6 |
HIP 47621 |
28.90 |
| 2026-10-10 12:00 |
09:44:07.59 |
-10:33:05.9 |
HIP 47621 |
29.46 |
| 2026-10-11 00:00 |
09:44:19.09 |
-10:35:06.3 |
HIP 47621 |
30.40 |
| 2026-10-11 12:00 |
09:44:30.50 |
-10:37:06.8 |
HIP 47621 |
31.67 |
| 2026-10-12 00:00 |
09:44:41.83 |
-10:39:07.3 |
HIP 47621 |
33.23 |
| 2026-10-12 12:00 |
09:44:53.08 |
-10:41:08.0 |
HIP 48007 |
33.88 |
| 2026-10-13 00:00 |
09:45:04.24 |
-10:43:08.7 |
HIP 48007 |
30.99 |
| 2026-10-13 12:00 |
09:45:15.31 |
-10:45:09.5 |
HIP 48007 |
28.24 |
| 2026-10-14 00:00 |
09:45:26.30 |
-10:47:10.3 |
HIP 48007 |
25.66 |
| 2026-10-14 12:00 |
09:45:37.20 |
-10:49:11.2 |
HIP 48007 |
23.30 |
| 2026-10-15 00:00 |
09:45:48.02 |
-10:51:12.2 |
HIP 48007 |
21.24 |
| 2026-10-15 12:00 |
09:45:58.75 |
-10:53:13.1 |
HIP 48007 |
19.55 |
| 2026-10-16 00:00 |
09:46:09.39 |
-10:55:14.2 |
HIP 48007 |
18.33 |