| Parameter |
Value |
| Designation |
C/2008 L3 (Hill) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2008-04-22T09:56:00.726720Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:21Z |
| Obs used |
82 |
| NEO |
- |
| M1 |
10.500 |
| K1 |
21.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2008-06-26.0000000 |
| e |
0.99376090 |
| q (au) |
2.011243 |
| a (au) |
322.360884 |
| i (deg) |
100.200796 |
| Ω (om, deg) |
24.185456 |
| ω (w, deg) |
101.814452 |
| M (ma, deg) |
0.010998 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.825 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.825 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
08:09:46.22 |
-57:54:26.2 |
HIP 40310 |
33.90 |
| 2026-05-12 12:00 |
08:09:47.97 |
-57:53:42.7 |
HIP 40310 |
33.51 |
| 2026-05-13 00:00 |
08:09:49.76 |
-57:52:59.2 |
HIP 40310 |
33.12 |
| 2026-05-13 12:00 |
08:09:51.60 |
-57:52:16.0 |
HIP 40310 |
32.75 |
| 2026-05-14 00:00 |
08:09:53.49 |
-57:51:32.9 |
HIP 40310 |
32.38 |
| 2026-05-14 12:00 |
08:09:55.42 |
-57:50:50.1 |
HIP 40310 |
32.01 |
| 2026-05-15 00:00 |
08:09:57.40 |
-57:50:07.4 |
HIP 40310 |
31.66 |
| 2026-05-15 12:00 |
08:09:59.42 |
-57:49:24.9 |
HIP 40310 |
31.32 |
| 2026-05-16 00:00 |
08:10:01.48 |
-57:48:42.5 |
HIP 40310 |
30.98 |
| 2026-05-16 12:00 |
08:10:03.59 |
-57:48:00.4 |
HIP 40310 |
30.65 |
| 2026-05-17 00:00 |
08:10:05.75 |
-57:47:18.5 |
HIP 40310 |
30.34 |
| 2026-05-17 12:00 |
08:10:07.95 |
-57:46:36.7 |
HIP 40310 |
30.03 |
| 2026-05-18 00:00 |
08:10:10.19 |
-57:45:55.2 |
HIP 40310 |
29.73 |
| 2026-05-18 12:00 |
08:10:12.47 |
-57:45:13.9 |
HIP 40310 |
29.44 |
| 2026-05-19 00:00 |
08:10:14.80 |
-57:44:32.7 |
HIP 40310 |
29.16 |
| 2026-05-19 12:00 |
08:10:17.17 |
-57:43:51.8 |
HIP 40310 |
28.90 |
| 2026-05-20 00:00 |
08:10:19.59 |
-57:43:11.1 |
HIP 40310 |
28.64 |
| 2026-05-20 12:00 |
08:10:22.04 |
-57:42:30.7 |
HIP 40310 |
28.40 |
| 2026-05-21 00:00 |
08:10:24.54 |
-57:41:50.4 |
HIP 40310 |
28.17 |
| 2026-05-21 12:00 |
08:10:27.08 |
-57:41:10.4 |
HIP 40310 |
27.94 |
| 2026-05-22 00:00 |
08:10:29.66 |
-57:40:30.5 |
HIP 40310 |
27.74 |
| 2026-05-22 12:00 |
08:10:32.28 |
-57:39:50.9 |
HIP 40310 |
27.54 |
| 2026-05-23 00:00 |
08:10:34.94 |
-57:39:11.6 |
HIP 40310 |
27.36 |
| 2026-05-23 12:00 |
08:10:37.64 |
-57:38:32.5 |
HIP 40310 |
27.18 |
| 2026-05-24 00:00 |
08:10:40.39 |
-57:37:53.6 |
HIP 40310 |
27.03 |
| 2026-05-24 12:00 |
08:10:43.17 |
-57:37:14.9 |
HIP 40310 |
26.88 |
| 2026-05-25 00:00 |
08:10:45.99 |
-57:36:36.5 |
HIP 40310 |
26.75 |
| 2026-05-25 12:00 |
08:10:48.85 |
-57:35:58.3 |
HIP 40310 |
26.63 |
| 2026-05-26 00:00 |
08:10:51.75 |
-57:35:20.4 |
HIP 40310 |
26.53 |
| 2026-05-26 12:00 |
08:10:54.69 |
-57:34:42.7 |
HIP 40310 |
26.44 |
| 2026-05-27 00:00 |
08:10:57.67 |
-57:34:05.2 |
HIP 40310 |
26.36 |
| 2026-05-27 12:00 |
08:11:00.68 |
-57:33:28.0 |
HIP 40310 |
26.29 |
| 2026-05-28 00:00 |
08:11:03.74 |
-57:32:51.1 |
HIP 40310 |
26.25 |
| 2026-05-28 12:00 |
08:11:06.83 |
-57:32:14.4 |
HIP 40310 |
26.21 |
| 2026-05-29 00:00 |
08:11:09.95 |
-57:31:37.9 |
HIP 40310 |
26.19 |
| 2026-05-29 12:00 |
08:11:13.12 |
-57:31:01.8 |
HIP 40310 |
26.18 |
| 2026-05-30 00:00 |
08:11:16.32 |
-57:30:25.8 |
HIP 40310 |
26.19 |
| 2026-05-30 12:00 |
08:11:19.56 |
-57:29:50.2 |
HIP 40310 |
26.21 |
| 2026-05-31 00:00 |
08:11:22.83 |
-57:29:14.8 |
HIP 40310 |
26.24 |
| 2026-05-31 12:00 |
08:11:26.14 |
-57:28:39.7 |
HIP 40310 |
26.29 |
| 2026-06-01 00:00 |
08:11:29.49 |
-57:28:04.8 |
HIP 40310 |
26.36 |
| 2026-06-01 12:00 |
08:11:32.87 |
-57:27:30.2 |
HIP 40310 |
26.43 |
| 2026-06-02 00:00 |
08:11:36.29 |
-57:26:55.9 |
HIP 40310 |
26.52 |