| Parameter |
Value |
| Designation |
C/1973 H1 (Huchra) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1973-03-11T12:39:25.813440Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:22Z |
| Obs used |
26 |
| NEO |
- |
| M1 |
9.300 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1973-05-30.0000000 |
| e |
0.97294134 |
| q (au) |
2.384240 |
| a (au) |
88.113743 |
| i (deg) |
48.329625 |
| Ω (om, deg) |
57.840302 |
| ω (w, deg) |
123.470767 |
| M (ma, deg) |
0.094701 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.905 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.905 |
| n |
6.000 |
| 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 |
01:03:18.11 |
-43:12:32.7 |
HIP 5006 |
10.45 |
| 2026-03-26 12:00 |
01:03:20.25 |
-43:12:21.7 |
HIP 5006 |
10.22 |
| 2026-03-27 00:00 |
01:03:22.39 |
-43:12:10.8 |
HIP 5006 |
10.01 |
| 2026-03-27 12:00 |
01:03:24.53 |
-43:12:00.1 |
HIP 5006 |
9.80 |
| 2026-03-28 00:00 |
01:03:26.68 |
-43:11:49.6 |
HIP 5006 |
9.61 |
| 2026-03-28 12:00 |
01:03:28.83 |
-43:11:39.2 |
HIP 5006 |
9.43 |
| 2026-03-29 00:00 |
01:03:30.99 |
-43:11:28.9 |
HIP 5006 |
9.26 |
| 2026-03-29 12:00 |
01:03:33.15 |
-43:11:18.9 |
HIP 5006 |
9.11 |
| 2026-03-30 00:00 |
01:03:35.31 |
-43:11:08.9 |
HIP 5006 |
8.98 |
| 2026-03-30 12:00 |
01:03:37.47 |
-43:10:59.1 |
HIP 5006 |
8.86 |
| 2026-03-31 00:00 |
01:03:39.63 |
-43:10:49.5 |
HIP 5006 |
8.76 |
| 2026-03-31 12:00 |
01:03:41.80 |
-43:10:40.1 |
HIP 5006 |
8.67 |
| 2026-04-01 00:00 |
01:03:43.97 |
-43:10:30.7 |
HIP 5006 |
8.61 |
| 2026-04-01 12:00 |
01:03:46.14 |
-43:10:21.6 |
HIP 5006 |
8.56 |
| 2026-04-02 00:00 |
01:03:48.31 |
-43:10:12.6 |
HIP 5006 |
8.53 |
| 2026-04-02 12:00 |
01:03:50.49 |
-43:10:03.7 |
HIP 5006 |
8.52 |
| 2026-04-03 00:00 |
01:03:52.66 |
-43:09:55.1 |
HIP 5006 |
8.52 |
| 2026-04-03 12:00 |
01:03:54.84 |
-43:09:46.5 |
HIP 5006 |
8.55 |
| 2026-04-04 00:00 |
01:03:57.02 |
-43:09:38.2 |
HIP 5006 |
8.59 |
| 2026-04-04 12:00 |
01:03:59.20 |
-43:09:30.0 |
HIP 5006 |
8.65 |
| 2026-04-05 00:00 |
01:04:01.38 |
-43:09:21.9 |
HIP 5006 |
8.73 |
| 2026-04-05 12:00 |
01:04:03.56 |
-43:09:14.0 |
HIP 5006 |
8.82 |
| 2026-04-06 00:00 |
01:04:05.74 |
-43:09:06.3 |
HIP 5006 |
8.93 |
| 2026-04-06 12:00 |
01:04:07.92 |
-43:08:58.7 |
HIP 5063 |
8.77 |
| 2026-04-07 00:00 |
01:04:10.10 |
-43:08:51.3 |
HIP 5063 |
8.38 |
| 2026-04-07 12:00 |
01:04:12.29 |
-43:08:44.1 |
HIP 5063 |
7.99 |
| 2026-04-08 00:00 |
01:04:14.47 |
-43:08:37.0 |
HIP 5063 |
7.60 |
| 2026-04-08 12:00 |
01:04:16.65 |
-43:08:30.1 |
HIP 5063 |
7.22 |
| 2026-04-09 00:00 |
01:04:18.83 |
-43:08:23.4 |
HIP 5063 |
6.84 |
| 2026-04-09 12:00 |
01:04:21.01 |
-43:08:16.8 |
HIP 5063 |
6.48 |
| 2026-04-10 00:00 |
01:04:23.20 |
-43:08:10.4 |
HIP 5063 |
6.12 |
| 2026-04-10 12:00 |
01:04:25.38 |
-43:08:04.1 |
HIP 5063 |
5.77 |
| 2026-04-11 00:00 |
01:04:27.56 |
-43:07:58.0 |
HIP 5063 |
5.42 |
| 2026-04-11 12:00 |
01:04:29.73 |
-43:07:52.1 |
HIP 5063 |
5.10 |
| 2026-04-12 00:00 |
01:04:31.91 |
-43:07:46.4 |
HIP 5063 |
4.78 |
| 2026-04-12 12:00 |
01:04:34.09 |
-43:07:40.8 |
HIP 5063 |
4.49 |
| 2026-04-13 00:00 |
01:04:36.26 |
-43:07:35.3 |
HIP 5063 |
4.22 |
| 2026-04-13 12:00 |
01:04:38.44 |
-43:07:30.1 |
HIP 5063 |
3.97 |
| 2026-04-14 00:00 |
01:04:40.61 |
-43:07:25.0 |
HIP 5063 |
3.75 |
| 2026-04-14 12:00 |
01:04:42.78 |
-43:07:20.1 |
HIP 5063 |
3.57 |
| 2026-04-15 00:00 |
01:04:44.95 |
-43:07:15.3 |
HIP 5063 |
3.43 |
| 2026-04-15 12:00 |
01:04:47.11 |
-43:07:10.8 |
HIP 5063 |
3.33 |
| 2026-04-16 00:00 |
01:04:49.27 |
-43:07:06.4 |
HIP 5063 |
3.29 |