| 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) |
| 2026-07-29 00:00 |
04:46:50.93 |
-19:55:09.2 |
HIP 22315 |
22.11 |
| 2026-07-29 12:00 |
04:46:52.89 |
-19:55:28.8 |
HIP 22315 |
21.72 |
| 2026-07-30 00:00 |
04:46:54.82 |
-19:55:48.7 |
HIP 22315 |
21.34 |
| 2026-07-30 12:00 |
04:46:56.74 |
-19:56:08.7 |
HIP 22315 |
20.98 |
| 2026-07-31 00:00 |
04:46:58.63 |
-19:56:28.9 |
HIP 22315 |
20.63 |
| 2026-07-31 12:00 |
04:47:00.51 |
-19:56:49.3 |
HIP 22315 |
20.30 |
| 2026-08-01 00:00 |
04:47:02.36 |
-19:57:09.9 |
HIP 22315 |
19.98 |
| 2026-08-01 12:00 |
04:47:04.19 |
-19:57:30.6 |
HIP 22315 |
19.68 |
| 2026-08-02 00:00 |
04:47:05.99 |
-19:57:51.6 |
HIP 22315 |
19.40 |
| 2026-08-02 12:00 |
04:47:07.78 |
-19:58:12.7 |
HIP 22315 |
19.13 |
| 2026-08-03 00:00 |
04:47:09.54 |
-19:58:34.0 |
HIP 22315 |
18.88 |
| 2026-08-03 12:00 |
04:47:11.28 |
-19:58:55.4 |
HIP 22315 |
18.65 |
| 2026-08-04 00:00 |
04:47:13.00 |
-19:59:17.1 |
HIP 22315 |
18.44 |
| 2026-08-04 12:00 |
04:47:14.70 |
-19:59:38.9 |
HIP 22315 |
18.25 |
| 2026-08-05 00:00 |
04:47:16.37 |
-20:00:00.9 |
HIP 22315 |
18.08 |
| 2026-08-05 12:00 |
04:47:18.02 |
-20:00:23.0 |
HIP 22315 |
17.93 |
| 2026-08-06 00:00 |
04:47:19.65 |
-20:00:45.4 |
HIP 22315 |
17.80 |
| 2026-08-06 12:00 |
04:47:21.25 |
-20:01:07.9 |
HIP 22315 |
17.70 |
| 2026-08-07 00:00 |
04:47:22.84 |
-20:01:30.5 |
HIP 22315 |
17.61 |
| 2026-08-07 12:00 |
04:47:24.39 |
-20:01:53.4 |
HIP 22315 |
17.54 |
| 2026-08-08 00:00 |
04:47:25.93 |
-20:02:16.4 |
HIP 22315 |
17.50 |
| 2026-08-08 12:00 |
04:47:27.44 |
-20:02:39.5 |
HIP 22315 |
17.48 |
| 2026-08-09 00:00 |
04:47:28.93 |
-20:03:02.8 |
HIP 22315 |
17.48 |
| 2026-08-09 12:00 |
04:47:30.39 |
-20:03:26.3 |
HIP 22315 |
17.50 |
| 2026-08-10 00:00 |
04:47:31.83 |
-20:03:49.9 |
HIP 22315 |
17.55 |
| 2026-08-10 12:00 |
04:47:33.24 |
-20:04:13.7 |
HIP 22315 |
17.61 |
| 2026-08-11 00:00 |
04:47:34.63 |
-20:04:37.6 |
HIP 22315 |
17.70 |
| 2026-08-11 12:00 |
04:47:36.00 |
-20:05:01.7 |
HIP 22315 |
17.80 |
| 2026-08-12 00:00 |
04:47:37.34 |
-20:05:26.0 |
HIP 22315 |
17.93 |
| 2026-08-12 12:00 |
04:47:38.66 |
-20:05:50.4 |
HIP 22269 |
17.79 |
| 2026-08-13 00:00 |
04:47:39.95 |
-20:06:14.9 |
HIP 22269 |
17.37 |
| 2026-08-13 12:00 |
04:47:41.21 |
-20:06:39.6 |
HIP 22269 |
16.96 |
| 2026-08-14 00:00 |
04:47:42.46 |
-20:07:04.4 |
HIP 22269 |
16.54 |
| 2026-08-14 12:00 |
04:47:43.67 |
-20:07:29.3 |
HIP 22269 |
16.14 |
| 2026-08-15 00:00 |
04:47:44.86 |
-20:07:54.4 |
HIP 22269 |
15.73 |
| 2026-08-15 12:00 |
04:47:46.03 |
-20:08:19.7 |
HIP 22269 |
15.33 |
| 2026-08-16 00:00 |
04:47:47.17 |
-20:08:45.0 |
HIP 22269 |
14.93 |
| 2026-08-16 12:00 |
04:47:48.28 |
-20:09:10.5 |
HIP 22269 |
14.53 |
| 2026-08-17 00:00 |
04:47:49.37 |
-20:09:36.1 |
HIP 22269 |
14.14 |
| 2026-08-17 12:00 |
04:47:50.44 |
-20:10:01.9 |
HIP 22269 |
13.75 |
| 2026-08-18 00:00 |
04:47:51.47 |
-20:10:27.8 |
HIP 22269 |
13.37 |
| 2026-08-18 12:00 |
04:47:52.48 |
-20:10:53.8 |
HIP 22269 |
12.99 |
| 2026-08-19 00:00 |
04:47:53.47 |
-20:11:19.9 |
HIP 22269 |
12.61 |