| Parameter |
Value |
| Designation |
C/1968 Q2 (Honda) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1968-11-03T20:03:50.408640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:19Z |
| Obs used |
35 |
| NEO |
- |
| M1 |
6.600 |
| K1 |
33.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1968-10-22.0000000 |
| e |
1.00000000 |
| q (au) |
1.099008 |
| a (au) |
- |
| i (deg) |
127.912524 |
| Ω (om, deg) |
253.292861 |
| ω (w, deg) |
282.803926 |
| M (ma, deg) |
- |
Magnitude
Scatter + Global Linear
$$
M_a = (7.086 + 3.394\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.086 |
| n |
3.394 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| 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) |
| 2026-09-20 00:00 |
12:57:40.45 |
+51:48:07.7 |
HIP 63000 |
28.89 |
| 2026-09-20 12:00 |
12:57:42.43 |
+51:47:58.4 |
HIP 63000 |
29.18 |
| 2026-09-21 00:00 |
12:57:44.42 |
+51:47:49.1 |
HIP 63000 |
29.48 |
| 2026-09-21 12:00 |
12:57:46.41 |
+51:47:40.0 |
HIP 63000 |
29.77 |
| 2026-09-22 00:00 |
12:57:48.40 |
+51:47:31.1 |
HIP 63000 |
30.07 |
| 2026-09-22 12:00 |
12:57:50.41 |
+51:47:22.2 |
HIP 63000 |
30.37 |
| 2026-09-23 00:00 |
12:57:52.41 |
+51:47:13.5 |
HIP 63000 |
30.67 |
| 2026-09-23 12:00 |
12:57:54.42 |
+51:47:05.0 |
HIP 63000 |
30.97 |
| 2026-09-24 00:00 |
12:57:56.44 |
+51:46:56.6 |
HIP 63000 |
31.28 |
| 2026-09-24 12:00 |
12:57:58.46 |
+51:46:48.3 |
HIP 63000 |
31.58 |
| 2026-09-25 00:00 |
12:58:00.48 |
+51:46:40.1 |
HIP 63000 |
31.89 |
| 2026-09-25 12:00 |
12:58:02.51 |
+51:46:32.1 |
HIP 63000 |
32.20 |
| 2026-09-26 00:00 |
12:58:04.54 |
+51:46:24.2 |
HIP 63000 |
32.51 |
| 2026-09-26 12:00 |
12:58:06.58 |
+51:46:16.5 |
HIP 63498 |
32.32 |
| 2026-09-27 00:00 |
12:58:08.62 |
+51:46:08.9 |
HIP 63498 |
32.00 |
| 2026-09-27 12:00 |
12:58:10.66 |
+51:46:01.4 |
HIP 63498 |
31.68 |
| 2026-09-28 00:00 |
12:58:12.71 |
+51:45:54.1 |
HIP 63498 |
31.37 |
| 2026-09-28 12:00 |
12:58:14.76 |
+51:45:47.0 |
HIP 63498 |
31.05 |
| 2026-09-29 00:00 |
12:58:16.82 |
+51:45:39.9 |
HIP 63498 |
30.74 |
| 2026-09-29 12:00 |
12:58:18.87 |
+51:45:33.0 |
HIP 63498 |
30.43 |
| 2026-09-30 00:00 |
12:58:20.93 |
+51:45:26.3 |
HIP 63498 |
30.13 |
| 2026-09-30 12:00 |
12:58:23.00 |
+51:45:19.7 |
HIP 63498 |
29.82 |
| 2026-10-01 00:00 |
12:58:25.06 |
+51:45:13.2 |
HIP 63498 |
29.52 |
| 2026-10-01 12:00 |
12:58:27.13 |
+51:45:06.9 |
HIP 63498 |
29.21 |
| 2026-10-02 00:00 |
12:58:29.20 |
+51:45:00.8 |
HIP 63498 |
28.91 |
| 2026-10-02 12:00 |
12:58:31.27 |
+51:44:54.7 |
HIP 63498 |
28.62 |
| 2026-10-03 00:00 |
12:58:33.35 |
+51:44:48.9 |
HIP 63498 |
28.32 |
| 2026-10-03 12:00 |
12:58:35.43 |
+51:44:43.1 |
HIP 63498 |
28.03 |
| 2026-10-04 00:00 |
12:58:37.51 |
+51:44:37.6 |
HIP 63498 |
27.74 |
| 2026-10-04 12:00 |
12:58:39.59 |
+51:44:32.1 |
HIP 63498 |
27.45 |
| 2026-10-05 00:00 |
12:58:41.67 |
+51:44:26.8 |
HIP 63498 |
27.17 |
| 2026-10-05 12:00 |
12:58:43.75 |
+51:44:21.7 |
HIP 63498 |
26.89 |
| 2026-10-06 00:00 |
12:58:45.84 |
+51:44:16.7 |
HIP 63498 |
26.61 |
| 2026-10-06 12:00 |
12:58:47.93 |
+51:44:11.9 |
HIP 63498 |
26.33 |
| 2026-10-07 00:00 |
12:58:50.01 |
+51:44:07.2 |
HIP 63498 |
26.06 |
| 2026-10-07 12:00 |
12:58:52.10 |
+51:44:02.7 |
HIP 63498 |
25.79 |
| 2026-10-08 00:00 |
12:58:54.19 |
+51:43:58.3 |
HIP 63498 |
25.53 |
| 2026-10-08 12:00 |
12:58:56.28 |
+51:43:54.1 |
HIP 63498 |
25.27 |
| 2026-10-09 00:00 |
12:58:58.37 |
+51:43:50.0 |
HIP 63498 |
25.01 |
| 2026-10-09 12:00 |
12:59:00.46 |
+51:43:46.1 |
HIP 63498 |
24.75 |
| 2026-10-10 00:00 |
12:59:02.55 |
+51:43:42.3 |
HIP 63498 |
24.50 |
| 2026-10-10 12:00 |
12:59:04.64 |
+51:43:38.7 |
HIP 63498 |
24.25 |
| 2026-10-11 00:00 |
12:59:06.73 |
+51:43:35.3 |
HIP 63498 |
24.01 |