| Parameter |
Value |
| Designation |
C/2003 H2 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2003-05-17T23:15:08.225280Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:29Z |
| Obs used |
189 |
| NEO |
- |
| M1 |
14.200 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2003-05-22.0000000 |
| e |
0.94291012 |
| q (au) |
2.178516 |
| a (au) |
38.159402 |
| i (deg) |
74.217540 |
| Ω (om, deg) |
79.838018 |
| ω (w, deg) |
155.082163 |
| M (ma, deg) |
0.016855 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.725 + 2.527\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.725 |
| n |
2.527 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.999 |
| 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) |
| 2026-09-20 00:00 |
04:47:59.95 |
-20:41:51.4 |
HIP 22277 |
7.42 |
| 2026-09-20 12:00 |
04:47:59.14 |
-20:42:20.9 |
HIP 22277 |
6.89 |
| 2026-09-21 00:00 |
04:47:58.31 |
-20:42:50.4 |
HIP 22277 |
6.36 |
| 2026-09-21 12:00 |
04:47:57.45 |
-20:43:19.9 |
HIP 22277 |
5.83 |
| 2026-09-22 00:00 |
04:47:56.56 |
-20:43:49.3 |
HIP 22277 |
5.30 |
| 2026-09-22 12:00 |
04:47:55.64 |
-20:44:18.7 |
HIP 22277 |
4.77 |
| 2026-09-23 00:00 |
04:47:54.69 |
-20:44:48.1 |
HIP 22277 |
4.23 |
| 2026-09-23 12:00 |
04:47:53.72 |
-20:45:17.5 |
HIP 22277 |
3.69 |
| 2026-09-24 00:00 |
04:47:52.72 |
-20:45:46.8 |
HIP 22277 |
3.15 |
| 2026-09-24 12:00 |
04:47:51.69 |
-20:46:16.0 |
HIP 22277 |
2.61 |
| 2026-09-25 00:00 |
04:47:50.64 |
-20:46:45.2 |
HIP 22277 |
2.06 |
| 2026-09-25 12:00 |
04:47:49.56 |
-20:47:14.4 |
HIP 22277 |
1.51 |
| 2026-09-26 00:00 |
04:47:48.45 |
-20:47:43.5 |
HIP 22277 |
0.96 |
| 2026-09-26 12:00 |
04:47:47.31 |
-20:48:12.6 |
HIP 22277 |
0.41 |
| 2026-09-27 00:00 |
04:47:46.15 |
-20:48:41.6 |
HIP 22277 |
0.15 |
| 2026-09-27 12:00 |
04:47:44.96 |
-20:49:10.6 |
HIP 22277 |
0.70 |
| 2026-09-28 00:00 |
04:47:43.74 |
-20:49:39.5 |
HIP 22277 |
1.26 |
| 2026-09-28 12:00 |
04:47:42.50 |
-20:50:08.4 |
HIP 22277 |
1.82 |
| 2026-09-29 00:00 |
04:47:41.23 |
-20:50:37.1 |
HIP 22277 |
2.39 |
| 2026-09-29 12:00 |
04:47:39.93 |
-20:51:05.9 |
HIP 22277 |
2.96 |
| 2026-09-30 00:00 |
04:47:38.60 |
-20:51:34.5 |
HIP 22277 |
3.52 |
| 2026-09-30 12:00 |
04:47:37.25 |
-20:52:03.1 |
HIP 22277 |
4.10 |
| 2026-10-01 00:00 |
04:47:35.87 |
-20:52:31.6 |
HIP 22277 |
4.67 |
| 2026-10-01 12:00 |
04:47:34.47 |
-20:53:00.1 |
HIP 22277 |
5.25 |
| 2026-10-02 00:00 |
04:47:33.04 |
-20:53:28.5 |
HIP 22277 |
5.82 |
| 2026-10-02 12:00 |
04:47:31.58 |
-20:53:56.7 |
HIP 22277 |
6.40 |
| 2026-10-03 00:00 |
04:47:30.10 |
-20:54:25.0 |
HIP 22277 |
6.99 |
| 2026-10-03 12:00 |
04:47:28.59 |
-20:54:53.1 |
HIP 22277 |
7.57 |
| 2026-10-04 00:00 |
04:47:27.05 |
-20:55:21.1 |
HIP 22277 |
8.16 |
| 2026-10-04 12:00 |
04:47:25.49 |
-20:55:49.1 |
HIP 22277 |
8.75 |
| 2026-10-05 00:00 |
04:47:23.90 |
-20:56:17.0 |
HIP 22277 |
9.34 |
| 2026-10-05 12:00 |
04:47:22.28 |
-20:56:44.7 |
HIP 22277 |
9.94 |
| 2026-10-06 00:00 |
04:47:20.64 |
-20:57:12.4 |
HIP 22277 |
10.54 |
| 2026-10-06 12:00 |
04:47:18.98 |
-20:57:40.0 |
HIP 22277 |
11.14 |
| 2026-10-07 00:00 |
04:47:17.29 |
-20:58:07.5 |
HIP 22277 |
11.74 |
| 2026-10-07 12:00 |
04:47:15.57 |
-20:58:34.8 |
HIP 22277 |
12.34 |
| 2026-10-08 00:00 |
04:47:13.83 |
-20:59:02.1 |
HIP 22277 |
12.95 |
| 2026-10-08 12:00 |
04:47:12.06 |
-20:59:29.3 |
HIP 22277 |
13.56 |
| 2026-10-09 00:00 |
04:47:10.26 |
-20:59:56.3 |
HIP 22231 |
13.11 |
| 2026-10-09 12:00 |
04:47:08.45 |
-21:00:23.2 |
HIP 22231 |
12.58 |
| 2026-10-10 00:00 |
04:47:06.60 |
-21:00:50.1 |
HIP 22231 |
12.05 |
| 2026-10-10 12:00 |
04:47:04.73 |
-21:01:16.8 |
HIP 22231 |
11.54 |
| 2026-10-11 00:00 |
04:47:02.84 |
-21:01:43.3 |
HIP 22231 |
11.04 |