| Parameter |
Value |
| Designation |
C/2004 H1 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2004-01-15T07:05:39.554880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:40Z |
| Obs used |
71 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2004-04-19.0000000 |
| e |
0.99989721 |
| q (au) |
2.080742 |
| a (au) |
20242.963449 |
| i (deg) |
140.672988 |
| Ω (om, deg) |
120.046982 |
| ω (w, deg) |
290.524558 |
| M (ma, deg) |
0.000032 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.724 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.724 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.800 |
| 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 |
01:00:47.63 |
+48:46:10.9 |
HIP 4637 |
17.11 |
| 2026-03-26 12:00 |
01:00:51.23 |
+48:46:15.8 |
HIP 4637 |
17.49 |
| 2026-03-27 00:00 |
01:00:54.83 |
+48:46:20.9 |
HIP 4637 |
17.88 |
| 2026-03-27 12:00 |
01:00:58.43 |
+48:46:26.3 |
HIP 4637 |
18.28 |
| 2026-03-28 00:00 |
01:01:02.04 |
+48:46:31.9 |
HIP 4637 |
18.68 |
| 2026-03-28 12:00 |
01:01:05.66 |
+48:46:37.8 |
HIP 4637 |
19.10 |
| 2026-03-29 00:00 |
01:01:09.27 |
+48:46:43.9 |
HIP 4637 |
19.52 |
| 2026-03-29 12:00 |
01:01:12.90 |
+48:46:50.3 |
HIP 4637 |
19.95 |
| 2026-03-30 00:00 |
01:01:16.53 |
+48:46:56.9 |
HIP 4637 |
20.39 |
| 2026-03-30 12:00 |
01:01:20.16 |
+48:47:03.7 |
HIP 4637 |
20.83 |
| 2026-03-31 00:00 |
01:01:23.79 |
+48:47:10.8 |
HIP 4857 |
20.74 |
| 2026-03-31 12:00 |
01:01:27.43 |
+48:47:18.1 |
HIP 4857 |
20.54 |
| 2026-04-01 00:00 |
01:01:31.07 |
+48:47:25.6 |
HIP 4857 |
20.36 |
| 2026-04-01 12:00 |
01:01:34.71 |
+48:47:33.4 |
HIP 4857 |
20.21 |
| 2026-04-02 00:00 |
01:01:38.36 |
+48:47:41.4 |
HIP 4857 |
20.07 |
| 2026-04-02 12:00 |
01:01:42.01 |
+48:47:49.7 |
HIP 4857 |
19.95 |
| 2026-04-03 00:00 |
01:01:45.66 |
+48:47:58.2 |
HIP 4857 |
19.86 |
| 2026-04-03 12:00 |
01:01:49.31 |
+48:48:06.9 |
HIP 4857 |
19.79 |
| 2026-04-04 00:00 |
01:01:52.96 |
+48:48:15.9 |
HIP 4857 |
19.74 |
| 2026-04-04 12:00 |
01:01:56.62 |
+48:48:25.1 |
HIP 4857 |
19.72 |
| 2026-04-05 00:00 |
01:02:00.28 |
+48:48:34.5 |
HIP 4989 |
19.51 |
| 2026-04-05 12:00 |
01:02:03.93 |
+48:48:44.2 |
HIP 4989 |
18.89 |
| 2026-04-06 00:00 |
01:02:07.59 |
+48:48:54.0 |
HIP 4989 |
18.27 |
| 2026-04-06 12:00 |
01:02:11.25 |
+48:49:04.2 |
HIP 4989 |
17.65 |
| 2026-04-07 00:00 |
01:02:14.91 |
+48:49:14.5 |
HIP 4989 |
17.03 |
| 2026-04-07 12:00 |
01:02:18.57 |
+48:49:25.1 |
HIP 4989 |
16.41 |
| 2026-04-08 00:00 |
01:02:22.22 |
+48:49:35.9 |
HIP 4989 |
15.79 |
| 2026-04-08 12:00 |
01:02:25.88 |
+48:49:46.9 |
HIP 4989 |
15.17 |
| 2026-04-09 00:00 |
01:02:29.54 |
+48:49:58.2 |
HIP 4989 |
14.55 |
| 2026-04-09 12:00 |
01:02:33.19 |
+48:50:09.6 |
HIP 4989 |
13.93 |
| 2026-04-10 00:00 |
01:02:36.85 |
+48:50:21.3 |
HIP 4989 |
13.31 |
| 2026-04-10 12:00 |
01:02:40.50 |
+48:50:33.2 |
HIP 4989 |
12.69 |
| 2026-04-11 00:00 |
01:02:44.15 |
+48:50:45.4 |
HIP 4989 |
12.08 |
| 2026-04-11 12:00 |
01:02:47.80 |
+48:50:57.7 |
HIP 4989 |
11.46 |
| 2026-04-12 00:00 |
01:02:51.44 |
+48:51:10.3 |
HIP 4989 |
10.85 |
| 2026-04-12 12:00 |
01:02:55.09 |
+48:51:23.1 |
HIP 4989 |
10.24 |
| 2026-04-13 00:00 |
01:02:58.73 |
+48:51:36.2 |
HIP 4989 |
9.64 |
| 2026-04-13 12:00 |
01:03:02.36 |
+48:51:49.4 |
HIP 4989 |
9.04 |
| 2026-04-14 00:00 |
01:03:06.00 |
+48:52:02.8 |
HIP 4989 |
8.45 |
| 2026-04-14 12:00 |
01:03:09.63 |
+48:52:16.5 |
HIP 4989 |
7.87 |
| 2026-04-15 00:00 |
01:03:13.26 |
+48:52:30.4 |
HIP 4989 |
7.30 |
| 2026-04-15 12:00 |
01:03:16.88 |
+48:52:44.5 |
HIP 4989 |
6.74 |
| 2026-04-16 00:00 |
01:03:20.49 |
+48:52:58.8 |
HIP 4989 |
6.20 |