| 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 |
-0.983 |
| 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) |
| 2026-07-29 00:00 |
12:46:30.78 |
-51:23:56.6 |
HIP 62293 |
6.50 |
| 2026-07-29 12:00 |
12:46:31.60 |
-51:23:44.8 |
HIP 62293 |
6.71 |
| 2026-07-30 00:00 |
12:46:32.43 |
-51:23:33.2 |
HIP 62293 |
6.92 |
| 2026-07-30 12:00 |
12:46:33.28 |
-51:23:21.7 |
HIP 62293 |
7.13 |
| 2026-07-31 00:00 |
12:46:34.15 |
-51:23:10.2 |
HIP 62293 |
7.35 |
| 2026-07-31 12:00 |
12:46:35.03 |
-51:22:58.9 |
HIP 62293 |
7.56 |
| 2026-08-01 00:00 |
12:46:35.93 |
-51:22:47.6 |
HIP 62293 |
7.78 |
| 2026-08-01 12:00 |
12:46:36.84 |
-51:22:36.5 |
HIP 62293 |
8.00 |
| 2026-08-02 00:00 |
12:46:37.77 |
-51:22:25.4 |
HIP 62293 |
8.23 |
| 2026-08-02 12:00 |
12:46:38.71 |
-51:22:14.5 |
HIP 62293 |
8.45 |
| 2026-08-03 00:00 |
12:46:39.66 |
-51:22:03.6 |
HIP 62293 |
8.68 |
| 2026-08-03 12:00 |
12:46:40.64 |
-51:21:52.9 |
HIP 62293 |
8.90 |
| 2026-08-04 00:00 |
12:46:41.62 |
-51:21:42.2 |
HIP 62293 |
9.13 |
| 2026-08-04 12:00 |
12:46:42.62 |
-51:21:31.7 |
HIP 62293 |
9.36 |
| 2026-08-05 00:00 |
12:46:43.64 |
-51:21:21.2 |
HIP 62370 |
9.28 |
| 2026-08-05 12:00 |
12:46:44.67 |
-51:21:10.9 |
HIP 62370 |
9.07 |
| 2026-08-06 00:00 |
12:46:45.72 |
-51:21:00.7 |
HIP 62370 |
8.87 |
| 2026-08-06 12:00 |
12:46:46.78 |
-51:20:50.5 |
HIP 62370 |
8.67 |
| 2026-08-07 00:00 |
12:46:47.85 |
-51:20:40.5 |
HIP 62370 |
8.47 |
| 2026-08-07 12:00 |
12:46:48.94 |
-51:20:30.6 |
HIP 62370 |
8.28 |
| 2026-08-08 00:00 |
12:46:50.05 |
-51:20:20.8 |
HIP 62370 |
8.09 |
| 2026-08-08 12:00 |
12:46:51.16 |
-51:20:11.1 |
HIP 62370 |
7.91 |
| 2026-08-09 00:00 |
12:46:52.30 |
-51:20:01.5 |
HIP 62370 |
7.73 |
| 2026-08-09 12:00 |
12:46:53.44 |
-51:19:52.1 |
HIP 62370 |
7.55 |
| 2026-08-10 00:00 |
12:46:54.60 |
-51:19:42.7 |
HIP 62370 |
7.38 |
| 2026-08-10 12:00 |
12:46:55.78 |
-51:19:33.4 |
HIP 62370 |
7.22 |
| 2026-08-11 00:00 |
12:46:56.96 |
-51:19:24.3 |
HIP 62370 |
7.06 |
| 2026-08-11 12:00 |
12:46:58.17 |
-51:19:15.3 |
HIP 62370 |
6.91 |
| 2026-08-12 00:00 |
12:46:59.38 |
-51:19:06.4 |
HIP 62370 |
6.76 |
| 2026-08-12 12:00 |
12:47:00.61 |
-51:18:57.6 |
HIP 62370 |
6.62 |
| 2026-08-13 00:00 |
12:47:01.86 |
-51:18:48.9 |
HIP 62370 |
6.50 |
| 2026-08-13 12:00 |
12:47:03.11 |
-51:18:40.3 |
HIP 62370 |
6.38 |
| 2026-08-14 00:00 |
12:47:04.38 |
-51:18:31.9 |
HIP 62370 |
6.27 |
| 2026-08-14 12:00 |
12:47:05.67 |
-51:18:23.5 |
HIP 62370 |
6.16 |
| 2026-08-15 00:00 |
12:47:06.96 |
-51:18:15.3 |
HIP 62370 |
6.07 |
| 2026-08-15 12:00 |
12:47:08.27 |
-51:18:07.2 |
HIP 62370 |
6.00 |
| 2026-08-16 00:00 |
12:47:09.59 |
-51:17:59.2 |
HIP 62370 |
5.93 |
| 2026-08-16 12:00 |
12:47:10.93 |
-51:17:51.4 |
HIP 62370 |
5.87 |
| 2026-08-17 00:00 |
12:47:12.28 |
-51:17:43.6 |
HIP 62370 |
5.83 |
| 2026-08-17 12:00 |
12:47:13.64 |
-51:17:36.0 |
HIP 62370 |
5.80 |
| 2026-08-18 00:00 |
12:47:15.01 |
-51:17:28.5 |
HIP 62370 |
5.78 |
| 2026-08-18 12:00 |
12:47:16.40 |
-51:17:21.1 |
HIP 62370 |
5.78 |
| 2026-08-19 00:00 |
12:47:17.80 |
-51:17:13.8 |
HIP 62370 |
5.79 |