C/2008 H1 (LINEAR)
| Parameter |
Value |
| Designation |
C/2008 H1 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2008-03-16T10:10:14.488320Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:18Z |
| Obs used |
252 |
| NEO |
- |
| M1 |
13.300 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2008-05-16.0000000 |
| e |
0.94658786 |
| q (au) |
2.760294 |
| a (au) |
51.679144 |
| i (deg) |
75.492175 |
| Ω (om, deg) |
34.630430 |
| ω (w, deg) |
96.043511 |
| M (ma, deg) |
0.160706 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.423 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.423 |
| n |
2.000 |
| gf |
0.983 |
| gb |
-0.505 |
| k |
1.000 |
| δ90 |
9.932 |
| 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 |
12:47:01.08 |
-81:01:17.5 |
HIP 62590 |
20.07 |
| 2026-02-03 12:00 |
12:46:49.38 |
-81:02:03.6 |
HIP 62590 |
20.94 |
| 2026-02-04 00:00 |
12:46:37.49 |
-81:02:49.3 |
HIP 62590 |
21.81 |
| 2026-02-04 12:00 |
12:46:25.41 |
-81:03:34.8 |
HIP 62590 |
22.68 |
| 2026-02-05 00:00 |
12:46:13.13 |
-81:04:19.9 |
HIP 62590 |
23.55 |
| 2026-02-05 12:00 |
12:46:00.66 |
-81:05:04.8 |
HIP 62590 |
24.42 |
| 2026-02-06 00:00 |
12:45:48.00 |
-81:05:49.3 |
HIP 62060 |
24.77 |
| 2026-02-06 12:00 |
12:45:35.15 |
-81:06:33.5 |
HIP 62060 |
23.94 |
| 2026-02-07 00:00 |
12:45:22.11 |
-81:07:17.4 |
HIP 62060 |
23.12 |
| 2026-02-07 12:00 |
12:45:08.87 |
-81:08:01.0 |
HIP 62060 |
22.30 |
| 2026-02-08 00:00 |
12:44:55.44 |
-81:08:44.3 |
HIP 62060 |
21.50 |
| 2026-02-08 12:00 |
12:44:41.83 |
-81:09:27.2 |
HIP 62060 |
20.70 |
| 2026-02-09 00:00 |
12:44:28.02 |
-81:10:09.7 |
HIP 62060 |
19.92 |
| 2026-02-09 12:00 |
12:44:14.03 |
-81:10:52.0 |
HIP 62060 |
19.15 |
| 2026-02-10 00:00 |
12:43:59.84 |
-81:11:33.9 |
HIP 62060 |
18.40 |
| 2026-02-10 12:00 |
12:43:45.47 |
-81:12:15.4 |
HIP 62060 |
17.67 |
| 2026-02-11 00:00 |
12:43:30.91 |
-81:12:56.6 |
HIP 62060 |
16.95 |
| 2026-02-11 12:00 |
12:43:16.17 |
-81:13:37.4 |
HIP 62060 |
16.25 |
| 2026-02-12 00:00 |
12:43:01.24 |
-81:14:17.8 |
HIP 62060 |
15.58 |
| 2026-02-12 12:00 |
12:42:46.13 |
-81:14:57.9 |
HIP 62060 |
14.94 |
| 2026-02-13 00:00 |
12:42:30.83 |
-81:15:37.6 |
HIP 62060 |
14.33 |
| 2026-02-13 12:00 |
12:42:15.35 |
-81:16:17.0 |
HIP 62060 |
13.76 |
| 2026-02-14 00:00 |
12:41:59.69 |
-81:16:55.9 |
HIP 62060 |
13.22 |
| 2026-02-14 12:00 |
12:41:43.84 |
-81:17:34.5 |
HIP 62060 |
12.73 |
| 2026-02-15 00:00 |
12:41:27.82 |
-81:18:12.7 |
HIP 62060 |
12.30 |
| 2026-02-15 12:00 |
12:41:11.62 |
-81:18:50.5 |
HIP 62060 |
11.91 |
| 2026-02-16 00:00 |
12:40:55.24 |
-81:19:27.9 |
HIP 62060 |
11.59 |
| 2026-02-16 12:00 |
12:40:38.69 |
-81:20:04.9 |
HIP 62060 |
11.34 |
| 2026-02-17 00:00 |
12:40:21.96 |
-81:20:41.4 |
HIP 62060 |
11.16 |
| 2026-02-17 12:00 |
12:40:05.05 |
-81:21:17.6 |
HIP 62060 |
11.05 |
| 2026-02-18 00:00 |
12:39:47.98 |
-81:21:53.4 |
HIP 62060 |
11.02 |
| 2026-02-18 12:00 |
12:39:30.73 |
-81:22:28.7 |
HIP 62060 |
11.07 |
| 2026-02-19 00:00 |
12:39:13.31 |
-81:23:03.7 |
HIP 62060 |
11.19 |
| 2026-02-19 12:00 |
12:38:55.73 |
-81:23:38.2 |
HIP 62060 |
11.39 |
| 2026-02-20 00:00 |
12:38:37.98 |
-81:24:12.2 |
HIP 62060 |
11.65 |
| 2026-02-20 12:00 |
12:38:20.06 |
-81:24:45.9 |
HIP 62060 |
11.98 |
| 2026-02-21 00:00 |
12:38:01.99 |
-81:25:19.1 |
HIP 62060 |
12.37 |
| 2026-02-21 12:00 |
12:37:43.75 |
-81:25:51.9 |
HIP 62060 |
12.82 |
| 2026-02-22 00:00 |
12:37:25.35 |
-81:26:24.2 |
HIP 62060 |
13.31 |
| 2026-02-22 12:00 |
12:37:06.79 |
-81:26:56.1 |
HIP 62060 |
13.85 |
| 2026-02-23 00:00 |
12:36:48.07 |
-81:27:27.5 |
HIP 62060 |
14.42 |
| 2026-02-23 12:00 |
12:36:29.21 |
-81:27:58.5 |
HIP 62060 |
15.03 |
| 2026-02-24 00:00 |
12:36:10.18 |
-81:28:29.0 |
HIP 62060 |
15.67 |