| 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) |
| 2026-03-26 00:00 |
12:50:53.59 |
-52:17:37.7 |
HIP 62774 |
13.23 |
| 2026-03-26 12:00 |
12:50:51.49 |
-52:17:34.5 |
HIP 62774 |
13.40 |
| 2026-03-27 00:00 |
12:50:49.38 |
-52:17:31.0 |
HIP 62774 |
13.58 |
| 2026-03-27 12:00 |
12:50:47.27 |
-52:17:27.5 |
HIP 62774 |
13.77 |
| 2026-03-28 00:00 |
12:50:45.15 |
-52:17:23.8 |
HIP 62774 |
13.95 |
| 2026-03-28 12:00 |
12:50:43.04 |
-52:17:19.9 |
HIP 62774 |
14.15 |
| 2026-03-29 00:00 |
12:50:40.92 |
-52:17:16.0 |
HIP 62774 |
14.34 |
| 2026-03-29 12:00 |
12:50:38.80 |
-52:17:11.8 |
HIP 62774 |
14.54 |
| 2026-03-30 00:00 |
12:50:36.68 |
-52:17:07.6 |
HIP 62774 |
14.74 |
| 2026-03-30 12:00 |
12:50:34.56 |
-52:17:03.2 |
HIP 62774 |
14.95 |
| 2026-03-31 00:00 |
12:50:32.43 |
-52:16:58.6 |
HIP 62774 |
15.16 |
| 2026-03-31 12:00 |
12:50:30.31 |
-52:16:53.9 |
HIP 62774 |
15.37 |
| 2026-04-01 00:00 |
12:50:28.18 |
-52:16:49.1 |
HIP 62774 |
15.59 |
| 2026-04-01 12:00 |
12:50:26.06 |
-52:16:44.2 |
HIP 62774 |
15.80 |
| 2026-04-02 00:00 |
12:50:23.93 |
-52:16:39.1 |
HIP 62774 |
16.03 |
| 2026-04-02 12:00 |
12:50:21.80 |
-52:16:33.8 |
HIP 62774 |
16.25 |
| 2026-04-03 00:00 |
12:50:19.67 |
-52:16:28.5 |
HIP 62774 |
16.48 |
| 2026-04-03 12:00 |
12:50:17.54 |
-52:16:23.0 |
HIP 62774 |
16.71 |
| 2026-04-04 00:00 |
12:50:15.42 |
-52:16:17.3 |
HIP 62774 |
16.94 |
| 2026-04-04 12:00 |
12:50:13.29 |
-52:16:11.6 |
HIP 62774 |
17.17 |
| 2026-04-05 00:00 |
12:50:11.16 |
-52:16:05.7 |
HIP 62774 |
17.41 |
| 2026-04-05 12:00 |
12:50:09.03 |
-52:15:59.6 |
HIP 62774 |
17.65 |
| 2026-04-06 00:00 |
12:50:06.91 |
-52:15:53.4 |
HIP 62774 |
17.89 |
| 2026-04-06 12:00 |
12:50:04.78 |
-52:15:47.1 |
HIP 62774 |
18.14 |
| 2026-04-07 00:00 |
12:50:02.65 |
-52:15:40.7 |
HIP 62774 |
18.38 |
| 2026-04-07 12:00 |
12:50:00.53 |
-52:15:34.1 |
HIP 62774 |
18.63 |
| 2026-04-08 00:00 |
12:49:58.41 |
-52:15:27.4 |
HIP 62774 |
18.88 |
| 2026-04-08 12:00 |
12:49:56.29 |
-52:15:20.6 |
HIP 62774 |
19.13 |
| 2026-04-09 00:00 |
12:49:54.17 |
-52:15:13.6 |
HIP 62774 |
19.38 |
| 2026-04-09 12:00 |
12:49:52.05 |
-52:15:06.5 |
HIP 62774 |
19.64 |
| 2026-04-10 00:00 |
12:49:49.93 |
-52:14:59.2 |
HIP 62774 |
19.90 |
| 2026-04-10 12:00 |
12:49:47.82 |
-52:14:51.9 |
HIP 62774 |
20.15 |
| 2026-04-11 00:00 |
12:49:45.71 |
-52:14:44.4 |
HIP 62774 |
20.41 |
| 2026-04-11 12:00 |
12:49:43.60 |
-52:14:36.8 |
HIP 62774 |
20.68 |
| 2026-04-12 00:00 |
12:49:41.49 |
-52:14:29.0 |
HIP 62774 |
20.94 |
| 2026-04-12 12:00 |
12:49:39.38 |
-52:14:21.1 |
HIP 62774 |
21.20 |
| 2026-04-13 00:00 |
12:49:37.28 |
-52:14:13.1 |
HIP 62774 |
21.47 |
| 2026-04-13 12:00 |
12:49:35.19 |
-52:14:05.0 |
HIP 62681 |
21.70 |
| 2026-04-14 00:00 |
12:49:33.09 |
-52:13:56.8 |
HIP 62681 |
21.73 |
| 2026-04-14 12:00 |
12:49:31.00 |
-52:13:48.4 |
HIP 62681 |
21.76 |
| 2026-04-15 00:00 |
12:49:28.91 |
-52:13:39.9 |
HIP 62681 |
21.79 |
| 2026-04-15 12:00 |
12:49:26.83 |
-52:13:31.2 |
HIP 62681 |
21.83 |
| 2026-04-16 00:00 |
12:49:24.75 |
-52:13:22.5 |
HIP 62681 |
21.87 |