メタデータ
| 項目 |
値 |
| Designation |
C/1967 Y1 (Ikeya-Seki) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1968-02-25T16:56:06.803520Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:17Z |
| Obs used |
197 |
| NEO |
- |
| M1 |
6.400 |
| K1 |
4.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1968-03-18.0000000 |
| e |
0.99915636 |
| q (au) |
1.696579 |
| a (au) |
2011.021687 |
| i (deg) |
129.315339 |
| Ω (om, deg) |
255.321380 |
| ω (w, deg) |
70.864407 |
| M (ma, deg) |
0.000233 |
等級
散乱 + 全体線形
$$
M_a = (2.937 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
2.937 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.991 |
| δ90 |
10.000 |
| パラメータ |
記号 |
範囲 |
説明 |
| 太陽・地球距離が1 AUのときの絶対等級 |
H0 |
-5 to 20 |
彗星の固有の明るさ |
| 測光スロープパラメータ |
n |
2 to 6 |
太陽距離に対する明るさ変化率 |
| 前方散乱非対称係数 |
gf |
0.8 to 1 |
前方散乱の強さ |
| 後方散乱非対称係数 |
gb |
-1 to -0.5 |
後方散乱の強さ |
| 分配係数 |
k |
0.8 to 1 |
前方/後方散乱の寄与比 |
| ダスト/ガス明るさ比 |
δ90 |
1 to 10 |
ダスト散乱とガス放射の相対寄与 |
参考: EPSC-DPS2025-160
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
03:02:41.18 |
-23:45:03.2 |
HIP 14130 |
7.24 |
| 2026-07-29 12:00 |
03:02:41.47 |
-23:45:16.3 |
HIP 14130 |
7.19 |
| 2026-07-30 00:00 |
03:02:41.74 |
-23:45:29.5 |
HIP 14130 |
7.15 |
| 2026-07-30 12:00 |
03:02:42.00 |
-23:45:42.7 |
HIP 14130 |
7.11 |
| 2026-07-31 00:00 |
03:02:42.25 |
-23:45:55.9 |
HIP 14130 |
7.07 |
| 2026-07-31 12:00 |
03:02:42.49 |
-23:46:09.3 |
HIP 14130 |
7.04 |
| 2026-08-01 00:00 |
03:02:42.71 |
-23:46:22.7 |
HIP 14130 |
7.01 |
| 2026-08-01 12:00 |
03:02:42.92 |
-23:46:36.1 |
HIP 14130 |
6.99 |
| 2026-08-02 00:00 |
03:02:43.12 |
-23:46:49.6 |
HIP 14130 |
6.97 |
| 2026-08-02 12:00 |
03:02:43.31 |
-23:47:03.2 |
HIP 14130 |
6.96 |
| 2026-08-03 00:00 |
03:02:43.49 |
-23:47:16.8 |
HIP 14130 |
6.95 |
| 2026-08-03 12:00 |
03:02:43.65 |
-23:47:30.4 |
HIP 14130 |
6.95 |
| 2026-08-04 00:00 |
03:02:43.80 |
-23:47:44.2 |
HIP 14130 |
6.95 |
| 2026-08-04 12:00 |
03:02:43.94 |
-23:47:58.0 |
HIP 14130 |
6.96 |
| 2026-08-05 00:00 |
03:02:44.06 |
-23:48:11.8 |
HIP 14130 |
6.97 |
| 2026-08-05 12:00 |
03:02:44.17 |
-23:48:25.7 |
HIP 14130 |
6.98 |
| 2026-08-06 00:00 |
03:02:44.28 |
-23:48:39.6 |
HIP 14130 |
7.00 |
| 2026-08-06 12:00 |
03:02:44.36 |
-23:48:53.6 |
HIP 14130 |
7.03 |
| 2026-08-07 00:00 |
03:02:44.44 |
-23:49:07.6 |
HIP 14130 |
7.06 |
| 2026-08-07 12:00 |
03:02:44.50 |
-23:49:21.7 |
HIP 14130 |
7.09 |
| 2026-08-08 00:00 |
03:02:44.55 |
-23:49:35.8 |
HIP 14130 |
7.13 |
| 2026-08-08 12:00 |
03:02:44.59 |
-23:49:50.0 |
HIP 14130 |
7.18 |
| 2026-08-09 00:00 |
03:02:44.61 |
-23:50:04.3 |
HIP 14130 |
7.23 |
| 2026-08-09 12:00 |
03:02:44.63 |
-23:50:18.5 |
HIP 14130 |
7.28 |
| 2026-08-10 00:00 |
03:02:44.63 |
-23:50:32.8 |
HIP 14130 |
7.34 |
| 2026-08-10 12:00 |
03:02:44.61 |
-23:50:47.2 |
HIP 14130 |
7.40 |
| 2026-08-11 00:00 |
03:02:44.59 |
-23:51:01.6 |
HIP 14130 |
7.47 |
| 2026-08-11 12:00 |
03:02:44.55 |
-23:51:16.0 |
HIP 14130 |
7.54 |
| 2026-08-12 00:00 |
03:02:44.50 |
-23:51:30.5 |
HIP 14130 |
7.62 |
| 2026-08-12 12:00 |
03:02:44.43 |
-23:51:45.0 |
HIP 14130 |
7.70 |
| 2026-08-13 00:00 |
03:02:44.36 |
-23:51:59.6 |
HIP 14130 |
7.79 |
| 2026-08-13 12:00 |
03:02:44.27 |
-23:52:14.1 |
HIP 14130 |
7.88 |
| 2026-08-14 00:00 |
03:02:44.17 |
-23:52:28.8 |
HIP 14130 |
7.97 |
| 2026-08-14 12:00 |
03:02:44.05 |
-23:52:43.4 |
HIP 14130 |
8.07 |
| 2026-08-15 00:00 |
03:02:43.92 |
-23:52:58.1 |
HIP 14130 |
8.17 |
| 2026-08-15 12:00 |
03:02:43.78 |
-23:53:12.8 |
HIP 14130 |
8.28 |
| 2026-08-16 00:00 |
03:02:43.63 |
-23:53:27.6 |
HIP 14130 |
8.39 |
| 2026-08-16 12:00 |
03:02:43.47 |
-23:53:42.4 |
HIP 14130 |
8.50 |
| 2026-08-17 00:00 |
03:02:43.29 |
-23:53:57.2 |
HIP 14130 |
8.62 |
| 2026-08-17 12:00 |
03:02:43.10 |
-23:54:12.0 |
HIP 14130 |
8.74 |
| 2026-08-18 00:00 |
03:02:42.89 |
-23:54:26.9 |
HIP 14130 |
8.87 |
| 2026-08-18 12:00 |
03:02:42.68 |
-23:54:41.8 |
HIP 14130 |
8.99 |
| 2026-08-19 00:00 |
03:02:42.45 |
-23:54:56.7 |
HIP 14130 |
9.13 |