| Parameter |
Value |
| Designation |
C/1968 H1 (Tago-Honda-Yamamoto) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1968-05-16T06:29:47.762880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:17Z |
| Obs used |
35 |
| NEO |
- |
| M1 |
9.800 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1968-05-17.0000000 |
| e |
0.99621615 |
| q (au) |
0.680377 |
| a (au) |
179.810794 |
| i (deg) |
102.170261 |
| Ω (om, deg) |
233.108209 |
| ω (w, deg) |
50.446716 |
| M (ma, deg) |
0.000298 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.114 + 2.389\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.114 |
| n |
2.389 |
| gf |
0.800 |
| gb |
-1.000 |
| k |
0.800 |
| δ90 |
1.000 |
| 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 |
03:27:27.66 |
-22:11:41.0 |
HIP 16067 |
9.63 |
| 2026-03-26 12:00 |
03:27:28.66 |
-22:11:27.6 |
HIP 16067 |
9.65 |
| 2026-03-27 00:00 |
03:27:29.67 |
-22:11:14.1 |
HIP 16067 |
9.68 |
| 2026-03-27 12:00 |
03:27:30.69 |
-22:11:00.8 |
HIP 16067 |
9.72 |
| 2026-03-28 00:00 |
03:27:31.72 |
-22:10:47.5 |
HIP 16067 |
9.77 |
| 2026-03-28 12:00 |
03:27:32.77 |
-22:10:34.2 |
HIP 16067 |
9.84 |
| 2026-03-29 00:00 |
03:27:33.82 |
-22:10:21.1 |
HIP 16067 |
9.92 |
| 2026-03-29 12:00 |
03:27:34.88 |
-22:10:08.0 |
HIP 16067 |
10.02 |
| 2026-03-30 00:00 |
03:27:35.94 |
-22:09:54.9 |
HIP 16067 |
10.12 |
| 2026-03-30 12:00 |
03:27:37.02 |
-22:09:41.9 |
HIP 16067 |
10.24 |
| 2026-03-31 00:00 |
03:27:38.11 |
-22:09:29.0 |
HIP 16067 |
10.37 |
| 2026-03-31 12:00 |
03:27:39.21 |
-22:09:16.1 |
HIP 16067 |
10.51 |
| 2026-04-01 00:00 |
03:27:40.31 |
-22:09:03.4 |
HIP 16067 |
10.66 |
| 2026-04-01 12:00 |
03:27:41.43 |
-22:08:50.6 |
HIP 16067 |
10.82 |
| 2026-04-02 00:00 |
03:27:42.55 |
-22:08:38.0 |
HIP 16067 |
10.99 |
| 2026-04-02 12:00 |
03:27:43.68 |
-22:08:25.4 |
HIP 16067 |
11.18 |
| 2026-04-03 00:00 |
03:27:44.82 |
-22:08:12.9 |
HIP 16067 |
11.37 |
| 2026-04-03 12:00 |
03:27:45.97 |
-22:08:00.4 |
HIP 16067 |
11.57 |
| 2026-04-04 00:00 |
03:27:47.13 |
-22:07:48.1 |
HIP 16067 |
11.77 |
| 2026-04-04 12:00 |
03:27:48.30 |
-22:07:35.8 |
HIP 16067 |
11.99 |
| 2026-04-05 00:00 |
03:27:49.47 |
-22:07:23.5 |
HIP 16067 |
12.22 |
| 2026-04-05 12:00 |
03:27:50.65 |
-22:07:11.4 |
HIP 16067 |
12.45 |
| 2026-04-06 00:00 |
03:27:51.84 |
-22:06:59.3 |
HIP 16067 |
12.69 |
| 2026-04-06 12:00 |
03:27:53.04 |
-22:06:47.3 |
HIP 16067 |
12.93 |
| 2026-04-07 00:00 |
03:27:54.25 |
-22:06:35.4 |
HIP 16067 |
13.18 |
| 2026-04-07 12:00 |
03:27:55.46 |
-22:06:23.5 |
HIP 16067 |
13.44 |
| 2026-04-08 00:00 |
03:27:56.69 |
-22:06:11.8 |
HIP 16067 |
13.70 |
| 2026-04-08 12:00 |
03:27:57.92 |
-22:06:00.1 |
HIP 16067 |
13.97 |
| 2026-04-09 00:00 |
03:27:59.16 |
-22:05:48.5 |
HIP 16067 |
14.24 |
| 2026-04-09 12:00 |
03:28:00.40 |
-22:05:37.0 |
HIP 16067 |
14.52 |
| 2026-04-10 00:00 |
03:28:01.65 |
-22:05:25.5 |
HIP 16067 |
14.81 |
| 2026-04-10 12:00 |
03:28:02.91 |
-22:05:14.1 |
HIP 16067 |
15.09 |
| 2026-04-11 00:00 |
03:28:04.18 |
-22:05:02.9 |
HIP 16067 |
15.39 |
| 2026-04-11 12:00 |
03:28:05.46 |
-22:04:51.7 |
HIP 16067 |
15.68 |
| 2026-04-12 00:00 |
03:28:06.74 |
-22:04:40.6 |
HIP 16067 |
15.98 |
| 2026-04-12 12:00 |
03:28:08.03 |
-22:04:29.5 |
HIP 16067 |
16.29 |
| 2026-04-13 00:00 |
03:28:09.33 |
-22:04:18.6 |
HIP 16067 |
16.59 |
| 2026-04-13 12:00 |
03:28:10.63 |
-22:04:07.7 |
HIP 16067 |
16.90 |
| 2026-04-14 00:00 |
03:28:11.94 |
-22:03:57.0 |
HIP 16067 |
17.22 |
| 2026-04-14 12:00 |
03:28:13.25 |
-22:03:46.3 |
HIP 16067 |
17.53 |
| 2026-04-15 00:00 |
03:28:14.58 |
-22:03:35.7 |
HIP 16067 |
17.85 |
| 2026-04-15 12:00 |
03:28:15.91 |
-22:03:25.2 |
HIP 16067 |
18.17 |
| 2026-04-16 00:00 |
03:28:17.24 |
-22:03:14.8 |
HIP 16067 |
18.50 |