C/1967 Y1 (Ikeya-Seki)
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) |
| 2026-02-03 00:00 |
02:57:01.21 |
-24:07:37.9 |
HIP 13696 |
13.72 |
| 2026-02-03 12:00 |
02:57:01.11 |
-24:07:24.3 |
HIP 13696 |
13.88 |
| 2026-02-04 00:00 |
02:57:01.02 |
-24:07:10.6 |
HIP 13696 |
14.05 |
| 2026-02-04 12:00 |
02:57:00.95 |
-24:06:56.8 |
HIP 13696 |
14.22 |
| 2026-02-05 00:00 |
02:57:00.88 |
-24:06:43.0 |
HIP 13696 |
14.39 |
| 2026-02-05 12:00 |
02:57:00.84 |
-24:06:29.2 |
HIP 13696 |
14.57 |
| 2026-02-06 00:00 |
02:57:00.80 |
-24:06:15.3 |
HIP 13696 |
14.75 |
| 2026-02-06 12:00 |
02:57:00.78 |
-24:06:01.4 |
HIP 13696 |
14.94 |
| 2026-02-07 00:00 |
02:57:00.77 |
-24:05:47.4 |
HIP 13782 |
15.01 |
| 2026-02-07 12:00 |
02:57:00.78 |
-24:05:33.4 |
HIP 13782 |
14.79 |
| 2026-02-08 00:00 |
02:57:00.80 |
-24:05:19.4 |
HIP 13782 |
14.57 |
| 2026-02-08 12:00 |
02:57:00.83 |
-24:05:05.4 |
HIP 13782 |
14.35 |
| 2026-02-09 00:00 |
02:57:00.87 |
-24:04:51.3 |
HIP 13782 |
14.13 |
| 2026-02-09 12:00 |
02:57:00.93 |
-24:04:37.1 |
HIP 13782 |
13.90 |
| 2026-02-10 00:00 |
02:57:01.01 |
-24:04:23.0 |
HIP 13782 |
13.68 |
| 2026-02-10 12:00 |
02:57:01.09 |
-24:04:08.8 |
HIP 13782 |
13.45 |
| 2026-02-11 00:00 |
02:57:01.19 |
-24:03:54.6 |
HIP 13782 |
13.23 |
| 2026-02-11 12:00 |
02:57:01.30 |
-24:03:40.4 |
HIP 13782 |
13.00 |
| 2026-02-12 00:00 |
02:57:01.43 |
-24:03:26.1 |
HIP 13782 |
12.77 |
| 2026-02-12 12:00 |
02:57:01.56 |
-24:03:11.8 |
HIP 13782 |
12.54 |
| 2026-02-13 00:00 |
02:57:01.72 |
-24:02:57.5 |
HIP 13782 |
12.31 |
| 2026-02-13 12:00 |
02:57:01.88 |
-24:02:43.1 |
HIP 13782 |
12.07 |
| 2026-02-14 00:00 |
02:57:02.06 |
-24:02:28.8 |
HIP 13782 |
11.84 |
| 2026-02-14 12:00 |
02:57:02.25 |
-24:02:14.4 |
HIP 13782 |
11.60 |
| 2026-02-15 00:00 |
02:57:02.45 |
-24:02:00.0 |
HIP 13782 |
11.36 |
| 2026-02-15 12:00 |
02:57:02.67 |
-24:01:45.6 |
HIP 13782 |
11.13 |
| 2026-02-16 00:00 |
02:57:02.90 |
-24:01:31.1 |
HIP 13782 |
10.89 |
| 2026-02-16 12:00 |
02:57:03.15 |
-24:01:16.7 |
HIP 13782 |
10.65 |
| 2026-02-17 00:00 |
02:57:03.40 |
-24:01:02.2 |
HIP 13782 |
10.40 |
| 2026-02-17 12:00 |
02:57:03.67 |
-24:00:47.7 |
HIP 13782 |
10.16 |
| 2026-02-18 00:00 |
02:57:03.95 |
-24:00:33.2 |
HIP 13782 |
9.92 |
| 2026-02-18 12:00 |
02:57:04.25 |
-24:00:18.7 |
HIP 13782 |
9.67 |
| 2026-02-19 00:00 |
02:57:04.56 |
-24:00:04.2 |
HIP 13782 |
9.42 |
| 2026-02-19 12:00 |
02:57:04.88 |
-23:59:49.7 |
HIP 13782 |
9.17 |
| 2026-02-20 00:00 |
02:57:05.21 |
-23:59:35.2 |
HIP 13782 |
8.92 |
| 2026-02-20 12:00 |
02:57:05.56 |
-23:59:20.6 |
HIP 13782 |
8.67 |
| 2026-02-21 00:00 |
02:57:05.92 |
-23:59:06.1 |
HIP 13782 |
8.42 |
| 2026-02-21 12:00 |
02:57:06.29 |
-23:58:51.5 |
HIP 13782 |
8.17 |
| 2026-02-22 00:00 |
02:57:06.68 |
-23:58:37.0 |
HIP 13782 |
7.91 |
| 2026-02-22 12:00 |
02:57:07.08 |
-23:58:22.5 |
HIP 13782 |
7.66 |
| 2026-02-23 00:00 |
02:57:07.49 |
-23:58:07.9 |
HIP 13782 |
7.40 |
| 2026-02-23 12:00 |
02:57:07.91 |
-23:57:53.4 |
HIP 13782 |
7.14 |
| 2026-02-24 00:00 |
02:57:08.34 |
-23:57:38.8 |
HIP 13782 |
6.88 |