| 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) |
| 2026-09-20 00:00 |
03:32:20.76 |
-22:34:25.7 |
HIP 16354 |
27.23 |
| 2026-09-20 12:00 |
03:32:19.92 |
-22:34:40.6 |
HIP 16354 |
27.21 |
| 2026-09-21 00:00 |
03:32:19.07 |
-22:34:55.5 |
HIP 16354 |
27.19 |
| 2026-09-21 12:00 |
03:32:18.20 |
-22:35:10.4 |
HIP 16354 |
27.17 |
| 2026-09-22 00:00 |
03:32:17.33 |
-22:35:25.3 |
HIP 16354 |
27.15 |
| 2026-09-22 12:00 |
03:32:16.45 |
-22:35:40.0 |
HIP 16354 |
27.14 |
| 2026-09-23 00:00 |
03:32:15.55 |
-22:35:54.8 |
HIP 16354 |
27.12 |
| 2026-09-23 12:00 |
03:32:14.64 |
-22:36:09.5 |
HIP 16354 |
27.11 |
| 2026-09-24 00:00 |
03:32:13.73 |
-22:36:24.2 |
HIP 16354 |
27.10 |
| 2026-09-24 12:00 |
03:32:12.80 |
-22:36:38.8 |
HIP 16354 |
27.09 |
| 2026-09-25 00:00 |
03:32:11.86 |
-22:36:53.4 |
HIP 16354 |
27.08 |
| 2026-09-25 12:00 |
03:32:10.91 |
-22:37:07.9 |
HIP 16354 |
27.07 |
| 2026-09-26 00:00 |
03:32:09.95 |
-22:37:22.4 |
HIP 16354 |
27.06 |
| 2026-09-26 12:00 |
03:32:08.97 |
-22:37:36.8 |
HIP 16354 |
27.06 |
| 2026-09-27 00:00 |
03:32:07.99 |
-22:37:51.2 |
HIP 16354 |
27.06 |
| 2026-09-27 12:00 |
03:32:07.00 |
-22:38:05.6 |
HIP 16354 |
27.05 |
| 2026-09-28 00:00 |
03:32:05.99 |
-22:38:19.9 |
HIP 16354 |
27.05 |
| 2026-09-28 12:00 |
03:32:04.98 |
-22:38:34.1 |
HIP 16354 |
27.06 |
| 2026-09-29 00:00 |
03:32:03.95 |
-22:38:48.3 |
HIP 16354 |
27.06 |
| 2026-09-29 12:00 |
03:32:02.92 |
-22:39:02.4 |
HIP 16354 |
27.07 |
| 2026-09-30 00:00 |
03:32:01.87 |
-22:39:16.5 |
HIP 16354 |
27.07 |
| 2026-09-30 12:00 |
03:32:00.82 |
-22:39:30.5 |
HIP 16354 |
27.08 |
| 2026-10-01 00:00 |
03:31:59.75 |
-22:39:44.4 |
HIP 16354 |
27.10 |
| 2026-10-01 12:00 |
03:31:58.67 |
-22:39:58.3 |
HIP 16354 |
27.11 |
| 2026-10-02 00:00 |
03:31:57.59 |
-22:40:12.1 |
HIP 16354 |
27.12 |
| 2026-10-02 12:00 |
03:31:56.49 |
-22:40:25.9 |
HIP 16354 |
27.14 |
| 2026-10-03 00:00 |
03:31:55.38 |
-22:40:39.6 |
HIP 16354 |
27.16 |
| 2026-10-03 12:00 |
03:31:54.27 |
-22:40:53.3 |
HIP 16354 |
27.18 |
| 2026-10-04 00:00 |
03:31:53.14 |
-22:41:06.8 |
HIP 16354 |
27.21 |
| 2026-10-04 12:00 |
03:31:52.01 |
-22:41:20.4 |
HIP 16354 |
27.23 |
| 2026-10-05 00:00 |
03:31:50.86 |
-22:41:33.8 |
HIP 16354 |
27.26 |
| 2026-10-05 12:00 |
03:31:49.71 |
-22:41:47.2 |
HIP 16354 |
27.29 |
| 2026-10-06 00:00 |
03:31:48.54 |
-22:42:00.5 |
HIP 16354 |
27.32 |
| 2026-10-06 12:00 |
03:31:47.37 |
-22:42:13.7 |
HIP 16354 |
27.36 |
| 2026-10-07 00:00 |
03:31:46.18 |
-22:42:26.9 |
HIP 16354 |
27.40 |
| 2026-10-07 12:00 |
03:31:44.99 |
-22:42:40.0 |
HIP 16354 |
27.44 |
| 2026-10-08 00:00 |
03:31:43.79 |
-22:42:53.0 |
HIP 16354 |
27.48 |
| 2026-10-08 12:00 |
03:31:42.58 |
-22:43:06.0 |
HIP 16354 |
27.52 |
| 2026-10-09 00:00 |
03:31:41.36 |
-22:43:18.9 |
HIP 16354 |
27.57 |
| 2026-10-09 12:00 |
03:31:40.13 |
-22:43:31.6 |
HIP 16354 |
27.62 |
| 2026-10-10 00:00 |
03:31:38.89 |
-22:43:44.4 |
HIP 16354 |
27.67 |
| 2026-10-10 12:00 |
03:31:37.65 |
-22:43:57.0 |
HIP 16354 |
27.72 |
| 2026-10-11 00:00 |
03:31:36.39 |
-22:44:09.6 |
HIP 16354 |
27.78 |