| Parameter |
Value |
| Designation |
C/1967 C1 (Seki) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1967-03-13T17:47:57.289920Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:17Z |
| Obs used |
18 |
| NEO |
- |
| M1 |
10.600 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1967-02-14.0000000 |
| e |
0.99990293 |
| q (au) |
0.457380 |
| a (au) |
4712.068054 |
| i (deg) |
106.468426 |
| Ω (om, deg) |
200.519565 |
| ω (w, deg) |
144.290739 |
| M (ma, deg) |
359.999915 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.171 + 3.612\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.171 |
| n |
3.612 |
| gf |
1.000 |
| gb |
-1.000 |
| 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) |
| 2026-05-12 00:00 |
12:47:45.77 |
-52:03:18.9 |
HIP 62346 |
17.78 |
| 2026-05-12 12:00 |
12:47:44.11 |
-52:03:04.9 |
HIP 62346 |
17.80 |
| 2026-05-13 00:00 |
12:47:42.46 |
-52:02:50.8 |
HIP 62346 |
17.83 |
| 2026-05-13 12:00 |
12:47:40.83 |
-52:02:36.6 |
HIP 62346 |
17.86 |
| 2026-05-14 00:00 |
12:47:39.20 |
-52:02:22.4 |
HIP 62346 |
17.91 |
| 2026-05-14 12:00 |
12:47:37.59 |
-52:02:08.1 |
HIP 62346 |
17.96 |
| 2026-05-15 00:00 |
12:47:35.98 |
-52:01:53.7 |
HIP 62346 |
18.02 |
| 2026-05-15 12:00 |
12:47:34.39 |
-52:01:39.2 |
HIP 62346 |
18.09 |
| 2026-05-16 00:00 |
12:47:32.82 |
-52:01:24.7 |
HIP 62346 |
18.17 |
| 2026-05-16 12:00 |
12:47:31.25 |
-52:01:10.1 |
HIP 62346 |
18.26 |
| 2026-05-17 00:00 |
12:47:29.70 |
-52:00:55.4 |
HIP 62346 |
18.35 |
| 2026-05-17 12:00 |
12:47:28.16 |
-52:00:40.7 |
HIP 62346 |
18.45 |
| 2026-05-18 00:00 |
12:47:26.63 |
-52:00:25.9 |
HIP 62346 |
18.56 |
| 2026-05-18 12:00 |
12:47:25.12 |
-52:00:11.1 |
HIP 62346 |
18.68 |
| 2026-05-19 00:00 |
12:47:23.61 |
-51:59:56.2 |
HIP 62346 |
18.80 |
| 2026-05-19 12:00 |
12:47:22.13 |
-51:59:41.2 |
HIP 62346 |
18.94 |
| 2026-05-20 00:00 |
12:47:20.65 |
-51:59:26.2 |
HIP 62346 |
19.07 |
| 2026-05-20 12:00 |
12:47:19.19 |
-51:59:11.1 |
HIP 62346 |
19.22 |
| 2026-05-21 00:00 |
12:47:17.74 |
-51:58:56.0 |
HIP 62346 |
19.37 |
| 2026-05-21 12:00 |
12:47:16.30 |
-51:58:40.8 |
HIP 62346 |
19.52 |
| 2026-05-22 00:00 |
12:47:14.88 |
-51:58:25.6 |
HIP 62346 |
19.69 |
| 2026-05-22 12:00 |
12:47:13.47 |
-51:58:10.3 |
HIP 62346 |
19.85 |
| 2026-05-23 00:00 |
12:47:12.08 |
-51:57:55.0 |
HIP 62346 |
20.03 |
| 2026-05-23 12:00 |
12:47:10.70 |
-51:57:39.6 |
HIP 62225 |
19.94 |
| 2026-05-24 00:00 |
12:47:09.33 |
-51:57:24.2 |
HIP 62225 |
19.65 |
| 2026-05-24 12:00 |
12:47:07.98 |
-51:57:08.7 |
HIP 62225 |
19.37 |
| 2026-05-25 00:00 |
12:47:06.64 |
-51:56:53.1 |
HIP 62225 |
19.09 |
| 2026-05-25 12:00 |
12:47:05.32 |
-51:56:37.6 |
HIP 62225 |
18.81 |
| 2026-05-26 00:00 |
12:47:04.00 |
-51:56:22.0 |
HIP 62225 |
18.53 |
| 2026-05-26 12:00 |
12:47:02.71 |
-51:56:06.3 |
HIP 62225 |
18.26 |
| 2026-05-27 00:00 |
12:47:01.43 |
-51:55:50.6 |
HIP 62225 |
17.99 |
| 2026-05-27 12:00 |
12:47:00.16 |
-51:55:34.9 |
HIP 62225 |
17.72 |
| 2026-05-28 00:00 |
12:46:58.91 |
-51:55:19.1 |
HIP 62225 |
17.46 |
| 2026-05-28 12:00 |
12:46:57.67 |
-51:55:03.3 |
HIP 62225 |
17.20 |
| 2026-05-29 00:00 |
12:46:56.44 |
-51:54:47.4 |
HIP 62225 |
16.95 |
| 2026-05-29 12:00 |
12:46:55.24 |
-51:54:31.6 |
HIP 62225 |
16.70 |
| 2026-05-30 00:00 |
12:46:54.04 |
-51:54:15.6 |
HIP 62225 |
16.46 |
| 2026-05-30 12:00 |
12:46:52.86 |
-51:53:59.7 |
HIP 62225 |
16.22 |
| 2026-05-31 00:00 |
12:46:51.70 |
-51:53:43.7 |
HIP 62225 |
15.99 |
| 2026-05-31 12:00 |
12:46:50.55 |
-51:53:27.7 |
HIP 62225 |
15.76 |
| 2026-06-01 00:00 |
12:46:49.41 |
-51:53:11.6 |
HIP 62225 |
15.54 |
| 2026-06-01 12:00 |
12:46:48.30 |
-51:52:55.6 |
HIP 62225 |
15.32 |
| 2026-06-02 00:00 |
12:46:47.19 |
-51:52:39.5 |
HIP 62225 |
15.11 |