C/1961 T1 (Seki)
| Parameter |
Value |
| Designation |
C/1961 T1 (Seki) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1961-10-10T15:34:49.782720Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:14Z |
| Obs used |
15 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1961-11-12.0000000 |
| e |
0.99215002 |
| q (au) |
0.681202 |
| a (au) |
86.777590 |
| i (deg) |
155.712858 |
| Ω (om, deg) |
247.357198 |
| ω (w, deg) |
126.592481 |
| M (ma, deg) |
0.039444 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.055 + 4.579\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.055 |
| n |
4.579 |
| gf |
0.800 |
| gb |
-1.000 |
| k |
0.800 |
| 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) |
| 2026-02-03 00:00 |
21:00:15.09 |
-38:36:47.9 |
HIP 103582 |
20.49 |
| 2026-02-03 12:00 |
21:00:16.90 |
-38:36:42.2 |
HIP 103582 |
20.62 |
| 2026-02-04 00:00 |
21:00:18.71 |
-38:36:36.6 |
HIP 103582 |
20.75 |
| 2026-02-04 12:00 |
21:00:20.52 |
-38:36:31.0 |
HIP 103582 |
20.89 |
| 2026-02-05 00:00 |
21:00:22.33 |
-38:36:25.5 |
HIP 103582 |
21.04 |
| 2026-02-05 12:00 |
21:00:24.14 |
-38:36:20.1 |
HIP 103582 |
21.19 |
| 2026-02-06 00:00 |
21:00:25.94 |
-38:36:14.8 |
HIP 103582 |
21.35 |
| 2026-02-06 12:00 |
21:00:27.75 |
-38:36:09.5 |
HIP 103582 |
21.51 |
| 2026-02-07 00:00 |
21:00:29.55 |
-38:36:04.3 |
HIP 103582 |
21.68 |
| 2026-02-07 12:00 |
21:00:31.36 |
-38:35:59.2 |
HIP 103582 |
21.86 |
| 2026-02-08 00:00 |
21:00:33.16 |
-38:35:54.2 |
HIP 103582 |
22.04 |
| 2026-02-08 12:00 |
21:00:34.96 |
-38:35:49.2 |
HIP 103582 |
22.22 |
| 2026-02-09 00:00 |
21:00:36.76 |
-38:35:44.3 |
HIP 103836 |
21.91 |
| 2026-02-09 12:00 |
21:00:38.55 |
-38:35:39.5 |
HIP 103836 |
21.55 |
| 2026-02-10 00:00 |
21:00:40.35 |
-38:35:34.8 |
HIP 103836 |
21.19 |
| 2026-02-10 12:00 |
21:00:42.14 |
-38:35:30.1 |
HIP 103836 |
20.83 |
| 2026-02-11 00:00 |
21:00:43.93 |
-38:35:25.5 |
HIP 103836 |
20.48 |
| 2026-02-11 12:00 |
21:00:45.71 |
-38:35:21.0 |
HIP 103836 |
20.12 |
| 2026-02-12 00:00 |
21:00:47.50 |
-38:35:16.6 |
HIP 103836 |
19.76 |
| 2026-02-12 12:00 |
21:00:49.28 |
-38:35:12.2 |
HIP 103836 |
19.41 |
| 2026-02-13 00:00 |
21:00:51.06 |
-38:35:07.9 |
HIP 103836 |
19.05 |
| 2026-02-13 12:00 |
21:00:52.83 |
-38:35:03.8 |
HIP 103836 |
18.70 |
| 2026-02-14 00:00 |
21:00:54.60 |
-38:34:59.6 |
HIP 103836 |
18.35 |
| 2026-02-14 12:00 |
21:00:56.37 |
-38:34:55.6 |
HIP 103836 |
18.00 |
| 2026-02-15 00:00 |
21:00:58.14 |
-38:34:51.6 |
HIP 103836 |
17.64 |
| 2026-02-15 12:00 |
21:00:59.90 |
-38:34:47.8 |
HIP 103836 |
17.29 |
| 2026-02-16 00:00 |
21:01:01.66 |
-38:34:44.0 |
HIP 103836 |
16.94 |
| 2026-02-16 12:00 |
21:01:03.41 |
-38:34:40.2 |
HIP 103836 |
16.60 |
| 2026-02-17 00:00 |
21:01:05.16 |
-38:34:36.6 |
HIP 103836 |
16.25 |
| 2026-02-17 12:00 |
21:01:06.91 |
-38:34:33.1 |
HIP 103836 |
15.90 |
| 2026-02-18 00:00 |
21:01:08.65 |
-38:34:29.6 |
HIP 103836 |
15.56 |
| 2026-02-18 12:00 |
21:01:10.39 |
-38:34:26.2 |
HIP 103836 |
15.21 |
| 2026-02-19 00:00 |
21:01:12.12 |
-38:34:22.9 |
HIP 103836 |
14.87 |
| 2026-02-19 12:00 |
21:01:13.85 |
-38:34:19.7 |
HIP 103836 |
14.53 |
| 2026-02-20 00:00 |
21:01:15.57 |
-38:34:16.5 |
HIP 103836 |
14.19 |
| 2026-02-20 12:00 |
21:01:17.29 |
-38:34:13.5 |
HIP 103836 |
13.85 |
| 2026-02-21 00:00 |
21:01:19.00 |
-38:34:10.5 |
HIP 103836 |
13.51 |
| 2026-02-21 12:00 |
21:01:20.71 |
-38:34:07.6 |
HIP 103836 |
13.17 |
| 2026-02-22 00:00 |
21:01:22.41 |
-38:34:04.8 |
HIP 103836 |
12.84 |
| 2026-02-22 12:00 |
21:01:24.11 |
-38:34:02.1 |
HIP 103836 |
12.50 |
| 2026-02-23 00:00 |
21:01:25.80 |
-38:33:59.4 |
HIP 103836 |
12.17 |
| 2026-02-23 12:00 |
21:01:27.49 |
-38:33:56.9 |
HIP 103836 |
11.84 |
| 2026-02-24 00:00 |
21:01:29.17 |
-38:33:54.4 |
HIP 103836 |
11.51 |