| Parameter |
Value |
| Designation |
C/2008 J6 (Hill) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2008-04-10T22:28:26.912640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:20Z |
| Obs used |
385 |
| NEO |
- |
| M1 |
13.400 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2008-07-07.0000000 |
| e |
1.00213779 |
| q (au) |
2.003509 |
| a (au) |
-937.187180 |
| i (deg) |
44.988370 |
| Ω (om, deg) |
298.179314 |
| ω (w, deg) |
10.700067 |
| M (ma, deg) |
0.002991 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.018 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.018 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.997 |
| 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) |
| 2026-03-26 00:00 |
07:10:28.50 |
+34:10:46.0 |
HIP 34556 |
13.03 |
| 2026-03-26 12:00 |
07:10:27.86 |
+34:10:35.4 |
HIP 34556 |
12.84 |
| 2026-03-27 00:00 |
07:10:27.25 |
+34:10:24.8 |
HIP 34556 |
12.65 |
| 2026-03-27 12:00 |
07:10:26.67 |
+34:10:14.1 |
HIP 34556 |
12.47 |
| 2026-03-28 00:00 |
07:10:26.12 |
+34:10:03.3 |
HIP 34556 |
12.30 |
| 2026-03-28 12:00 |
07:10:25.61 |
+34:09:52.5 |
HIP 34556 |
12.14 |
| 2026-03-29 00:00 |
07:10:25.14 |
+34:09:41.7 |
HIP 34556 |
11.98 |
| 2026-03-29 12:00 |
07:10:24.69 |
+34:09:30.7 |
HIP 34556 |
11.83 |
| 2026-03-30 00:00 |
07:10:24.28 |
+34:09:19.8 |
HIP 34556 |
11.69 |
| 2026-03-30 12:00 |
07:10:23.90 |
+34:09:08.8 |
HIP 34556 |
11.55 |
| 2026-03-31 00:00 |
07:10:23.56 |
+34:08:57.7 |
HIP 34556 |
11.43 |
| 2026-03-31 12:00 |
07:10:23.25 |
+34:08:46.6 |
HIP 34556 |
11.31 |
| 2026-04-01 00:00 |
07:10:22.97 |
+34:08:35.4 |
HIP 34556 |
11.20 |
| 2026-04-01 12:00 |
07:10:22.73 |
+34:08:24.2 |
HIP 34556 |
11.10 |
| 2026-04-02 00:00 |
07:10:22.51 |
+34:08:12.9 |
HIP 34556 |
11.01 |
| 2026-04-02 12:00 |
07:10:22.34 |
+34:08:01.6 |
HIP 34556 |
10.92 |
| 2026-04-03 00:00 |
07:10:22.19 |
+34:07:50.2 |
HIP 34556 |
10.85 |
| 2026-04-03 12:00 |
07:10:22.08 |
+34:07:38.8 |
HIP 34556 |
10.79 |
| 2026-04-04 00:00 |
07:10:22.00 |
+34:07:27.3 |
HIP 34556 |
10.73 |
| 2026-04-04 12:00 |
07:10:21.95 |
+34:07:15.8 |
HIP 34556 |
10.69 |
| 2026-04-05 00:00 |
07:10:21.94 |
+34:07:04.3 |
HIP 34556 |
10.65 |
| 2026-04-05 12:00 |
07:10:21.96 |
+34:06:52.7 |
HIP 34556 |
10.63 |
| 2026-04-06 00:00 |
07:10:22.01 |
+34:06:41.0 |
HIP 34556 |
10.61 |
| 2026-04-06 12:00 |
07:10:22.10 |
+34:06:29.3 |
HIP 34556 |
10.61 |
| 2026-04-07 00:00 |
07:10:22.22 |
+34:06:17.6 |
HIP 34556 |
10.62 |
| 2026-04-07 12:00 |
07:10:22.37 |
+34:06:05.8 |
HIP 34556 |
10.63 |
| 2026-04-08 00:00 |
07:10:22.55 |
+34:05:54.0 |
HIP 34556 |
10.66 |
| 2026-04-08 12:00 |
07:10:22.77 |
+34:05:42.2 |
HIP 34556 |
10.70 |
| 2026-04-09 00:00 |
07:10:23.02 |
+34:05:30.3 |
HIP 34556 |
10.75 |
| 2026-04-09 12:00 |
07:10:23.30 |
+34:05:18.4 |
HIP 34556 |
10.80 |
| 2026-04-10 00:00 |
07:10:23.62 |
+34:05:06.4 |
HIP 34556 |
10.87 |
| 2026-04-10 12:00 |
07:10:23.96 |
+34:04:54.4 |
HIP 34556 |
10.95 |
| 2026-04-11 00:00 |
07:10:24.35 |
+34:04:42.4 |
HIP 34556 |
11.04 |
| 2026-04-11 12:00 |
07:10:24.76 |
+34:04:30.3 |
HIP 34556 |
11.14 |
| 2026-04-12 00:00 |
07:10:25.20 |
+34:04:18.2 |
HIP 34556 |
11.25 |
| 2026-04-12 12:00 |
07:10:25.68 |
+34:04:06.1 |
HIP 34556 |
11.37 |
| 2026-04-13 00:00 |
07:10:26.19 |
+34:03:53.9 |
HIP 34556 |
11.50 |
| 2026-04-13 12:00 |
07:10:26.74 |
+34:03:41.7 |
HIP 34556 |
11.64 |
| 2026-04-14 00:00 |
07:10:27.31 |
+34:03:29.4 |
HIP 34556 |
11.79 |
| 2026-04-14 12:00 |
07:10:27.92 |
+34:03:17.2 |
HIP 34556 |
11.95 |
| 2026-04-15 00:00 |
07:10:28.56 |
+34:03:04.9 |
HIP 34556 |
12.12 |
| 2026-04-15 12:00 |
07:10:29.23 |
+34:02:52.5 |
HIP 34556 |
12.29 |
| 2026-04-16 00:00 |
07:10:29.94 |
+34:02:40.2 |
HIP 34556 |
12.48 |