C/2008 L3 (Hill)
| 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) |
| 2026-02-03 00:00 |
08:19:47.47 |
-59:59:03.8 |
HIP 40808 |
7.14 |
| 2026-02-03 12:00 |
08:19:40.69 |
-59:58:52.4 |
HIP 40808 |
7.33 |
| 2026-02-04 00:00 |
08:19:33.92 |
-59:58:40.5 |
HIP 40808 |
7.62 |
| 2026-02-04 12:00 |
08:19:27.17 |
-59:58:28.2 |
HIP 40808 |
8.00 |
| 2026-02-05 00:00 |
08:19:20.43 |
-59:58:15.4 |
HIP 40808 |
8.46 |
| 2026-02-05 12:00 |
08:19:13.70 |
-59:58:02.2 |
HIP 40808 |
8.99 |
| 2026-02-06 00:00 |
08:19:06.99 |
-59:57:48.6 |
HIP 40808 |
9.57 |
| 2026-02-06 12:00 |
08:19:00.30 |
-59:57:34.5 |
HIP 40808 |
10.20 |
| 2026-02-07 00:00 |
08:18:53.62 |
-59:57:20.0 |
HIP 40808 |
10.87 |
| 2026-02-07 12:00 |
08:18:46.96 |
-59:57:05.1 |
HIP 40808 |
11.57 |
| 2026-02-08 00:00 |
08:18:40.31 |
-59:56:49.8 |
HIP 40808 |
12.29 |
| 2026-02-08 12:00 |
08:18:33.68 |
-59:56:34.0 |
HIP 40808 |
13.04 |
| 2026-02-09 00:00 |
08:18:27.08 |
-59:56:17.8 |
HIP 40808 |
13.80 |
| 2026-02-09 12:00 |
08:18:20.49 |
-59:56:01.1 |
HIP 40808 |
14.58 |
| 2026-02-10 00:00 |
08:18:13.91 |
-59:55:44.1 |
HIP 40808 |
15.37 |
| 2026-02-10 12:00 |
08:18:07.36 |
-59:55:26.6 |
HIP 40808 |
16.17 |
| 2026-02-11 00:00 |
08:18:00.83 |
-59:55:08.7 |
HIP 40808 |
16.98 |
| 2026-02-11 12:00 |
08:17:54.33 |
-59:54:50.3 |
HIP 40808 |
17.80 |
| 2026-02-12 00:00 |
08:17:47.84 |
-59:54:31.6 |
HIP 40808 |
18.63 |
| 2026-02-12 12:00 |
08:17:41.37 |
-59:54:12.4 |
HIP 40808 |
19.46 |
| 2026-02-13 00:00 |
08:17:34.93 |
-59:53:52.8 |
HIP 40808 |
20.30 |
| 2026-02-13 12:00 |
08:17:28.51 |
-59:53:32.8 |
HIP 40808 |
21.14 |
| 2026-02-14 00:00 |
08:17:22.12 |
-59:53:12.4 |
HIP 40808 |
21.99 |
| 2026-02-14 12:00 |
08:17:15.75 |
-59:52:51.6 |
HIP 40418 |
22.49 |
| 2026-02-15 00:00 |
08:17:09.40 |
-59:52:30.3 |
HIP 40418 |
21.66 |
| 2026-02-15 12:00 |
08:17:03.08 |
-59:52:08.7 |
HIP 40418 |
20.84 |
| 2026-02-16 00:00 |
08:16:56.79 |
-59:51:46.6 |
HIP 40418 |
20.02 |
| 2026-02-16 12:00 |
08:16:50.52 |
-59:51:24.2 |
HIP 40418 |
19.20 |
| 2026-02-17 00:00 |
08:16:44.28 |
-59:51:01.3 |
HIP 40418 |
18.38 |
| 2026-02-17 12:00 |
08:16:38.07 |
-59:50:38.1 |
HIP 40418 |
17.57 |
| 2026-02-18 00:00 |
08:16:31.88 |
-59:50:14.4 |
HIP 40418 |
16.75 |
| 2026-02-18 12:00 |
08:16:25.73 |
-59:49:50.4 |
HIP 40418 |
15.95 |
| 2026-02-19 00:00 |
08:16:19.60 |
-59:49:26.0 |
HIP 40418 |
15.14 |
| 2026-02-19 12:00 |
08:16:13.50 |
-59:49:01.1 |
HIP 40418 |
14.34 |
| 2026-02-20 00:00 |
08:16:07.44 |
-59:48:35.9 |
HIP 40418 |
13.55 |
| 2026-02-20 12:00 |
08:16:01.40 |
-59:48:10.4 |
HIP 40418 |
12.77 |
| 2026-02-21 00:00 |
08:15:55.40 |
-59:47:44.4 |
HIP 40418 |
11.99 |
| 2026-02-21 12:00 |
08:15:49.42 |
-59:47:18.0 |
HIP 40418 |
11.22 |
| 2026-02-22 00:00 |
08:15:43.48 |
-59:46:51.3 |
HIP 40418 |
10.47 |
| 2026-02-22 12:00 |
08:15:37.58 |
-59:46:24.2 |
HIP 40418 |
9.73 |
| 2026-02-23 00:00 |
08:15:31.70 |
-59:45:56.7 |
HIP 40418 |
9.01 |
| 2026-02-23 12:00 |
08:15:25.86 |
-59:45:28.9 |
HIP 40418 |
8.32 |
| 2026-02-24 00:00 |
08:15:20.05 |
-59:45:00.7 |
HIP 40418 |
7.65 |