| Parameter |
Value |
| Designation |
C/2007 H2 (Skiff) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2007-02-17T01:18:40.541760Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:06Z |
| Obs used |
109 |
| NEO |
- |
| M1 |
18.300 |
| K1 |
6.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2007-04-24.0000000 |
| e |
0.97167863 |
| q (au) |
1.410452 |
| a (au) |
49.801695 |
| i (deg) |
52.190808 |
| Ω (om, deg) |
203.771836 |
| ω (w, deg) |
319.302431 |
| M (ma, deg) |
0.184936 |
Magnitude
Scatter + Global Linear
$$
M_a = (18.239 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
18.239 |
| n |
2.000 |
| gf |
0.929 |
| gb |
-0.626 |
| k |
0.989 |
| δ90 |
7.543 |
| 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) |
| 2026-09-20 00:00 |
21:26:52.58 |
+31:31:12.1 |
HIP 105971 |
19.94 |
| 2026-09-20 12:00 |
21:26:49.86 |
+31:30:40.5 |
HIP 105971 |
20.70 |
| 2026-09-21 00:00 |
21:26:47.15 |
+31:30:08.7 |
HIP 105971 |
21.46 |
| 2026-09-21 12:00 |
21:26:44.47 |
+31:29:36.8 |
HIP 105971 |
22.23 |
| 2026-09-22 00:00 |
21:26:41.81 |
+31:29:04.6 |
HIP 105971 |
22.99 |
| 2026-09-22 12:00 |
21:26:39.17 |
+31:28:32.3 |
HIP 105971 |
23.76 |
| 2026-09-23 00:00 |
21:26:36.55 |
+31:27:59.8 |
HIP 105971 |
24.52 |
| 2026-09-23 12:00 |
21:26:33.96 |
+31:27:27.2 |
HIP 105971 |
25.29 |
| 2026-09-24 00:00 |
21:26:31.38 |
+31:26:54.4 |
HIP 105971 |
26.06 |
| 2026-09-24 12:00 |
21:26:28.83 |
+31:26:21.4 |
HIP 105971 |
26.82 |
| 2026-09-25 00:00 |
21:26:26.30 |
+31:25:48.2 |
HIP 105971 |
27.59 |
| 2026-09-25 12:00 |
21:26:23.79 |
+31:25:14.9 |
HIP 105971 |
28.36 |
| 2026-09-26 00:00 |
21:26:21.31 |
+31:24:41.4 |
HIP 105971 |
29.12 |
| 2026-09-26 12:00 |
21:26:18.85 |
+31:24:07.8 |
HIP 105971 |
29.89 |
| 2026-09-27 00:00 |
21:26:16.41 |
+31:23:34.0 |
HIP 105971 |
30.65 |
| 2026-09-27 12:00 |
21:26:13.99 |
+31:23:00.1 |
HIP 105971 |
31.41 |
| 2026-09-28 00:00 |
21:26:11.60 |
+31:22:26.0 |
HIP 105971 |
32.18 |
| 2026-09-28 12:00 |
21:26:09.23 |
+31:21:51.7 |
HIP 105971 |
32.94 |
| 2026-09-29 00:00 |
21:26:06.89 |
+31:21:17.4 |
HIP 105688 |
33.57 |
| 2026-09-29 12:00 |
21:26:04.57 |
+31:20:42.8 |
HIP 105688 |
32.81 |
| 2026-09-30 00:00 |
21:26:02.27 |
+31:20:08.2 |
HIP 105688 |
32.05 |
| 2026-09-30 12:00 |
21:26:00.00 |
+31:19:33.4 |
HIP 105688 |
31.30 |
| 2026-10-01 00:00 |
21:25:57.76 |
+31:18:58.4 |
HIP 105688 |
30.54 |
| 2026-10-01 12:00 |
21:25:55.54 |
+31:18:23.4 |
HIP 105688 |
29.79 |
| 2026-10-02 00:00 |
21:25:53.34 |
+31:17:48.2 |
HIP 105688 |
29.04 |
| 2026-10-02 12:00 |
21:25:51.17 |
+31:17:12.8 |
HIP 105688 |
28.30 |
| 2026-10-03 00:00 |
21:25:49.02 |
+31:16:37.4 |
HIP 105688 |
27.55 |
| 2026-10-03 12:00 |
21:25:46.90 |
+31:16:01.8 |
HIP 105688 |
26.81 |
| 2026-10-04 00:00 |
21:25:44.81 |
+31:15:26.1 |
HIP 105688 |
26.06 |
| 2026-10-04 12:00 |
21:25:42.74 |
+31:14:50.3 |
HIP 105688 |
25.33 |
| 2026-10-05 00:00 |
21:25:40.70 |
+31:14:14.4 |
HIP 105688 |
24.59 |
| 2026-10-05 12:00 |
21:25:38.68 |
+31:13:38.3 |
HIP 105688 |
23.86 |
| 2026-10-06 00:00 |
21:25:36.69 |
+31:13:02.2 |
HIP 105688 |
23.13 |
| 2026-10-06 12:00 |
21:25:34.73 |
+31:12:25.9 |
HIP 105688 |
22.40 |
| 2026-10-07 00:00 |
21:25:32.79 |
+31:11:49.6 |
HIP 105688 |
21.68 |
| 2026-10-07 12:00 |
21:25:30.88 |
+31:11:13.1 |
HIP 105688 |
20.96 |
| 2026-10-08 00:00 |
21:25:29.00 |
+31:10:36.6 |
HIP 105688 |
20.24 |
| 2026-10-08 12:00 |
21:25:27.14 |
+31:10:00.0 |
HIP 105688 |
19.53 |
| 2026-10-09 00:00 |
21:25:25.32 |
+31:09:23.2 |
HIP 105688 |
18.82 |
| 2026-10-09 12:00 |
21:25:23.52 |
+31:08:46.4 |
HIP 105688 |
18.11 |
| 2026-10-10 00:00 |
21:25:21.75 |
+31:08:09.5 |
HIP 105688 |
17.42 |
| 2026-10-10 12:00 |
21:25:20.00 |
+31:07:32.6 |
HIP 105688 |
16.72 |
| 2026-10-11 00:00 |
21:25:18.29 |
+31:06:55.5 |
HIP 105688 |
16.04 |