メタデータ
| 項目 |
値 |
| Designation |
C/1987 W1 (Ichimura) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1988-01-10T02:29:58.758720Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:36Z |
| Obs used |
48 |
| NEO |
- |
| M1 |
8.900 |
| K1 |
10.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1987-11-28.0000000 |
| e |
0.99999939 |
| q (au) |
0.199518 |
| a (au) |
327902.551553 |
| i (deg) |
41.620500 |
| Ω (om, deg) |
226.527901 |
| ω (w, deg) |
329.292632 |
| M (ma, deg) |
360.000000 |
等級
散乱 + 全体線形
$$
M_a = (10.506 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.506 |
| n |
2.000 |
| gf |
0.800 |
| gb |
-1.000 |
| k |
0.843 |
| δ90 |
1.000 |
| 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 |
00:26:01.79 |
+28:45:54.4 |
HIP 2055 |
10.53 |
| 2026-07-29 12:00 |
00:26:00.88 |
+28:46:00.1 |
HIP 2055 |
10.44 |
| 2026-07-30 00:00 |
00:25:59.94 |
+28:46:05.6 |
HIP 2055 |
10.36 |
| 2026-07-30 12:00 |
00:25:59.00 |
+28:46:11.1 |
HIP 2055 |
10.28 |
| 2026-07-31 00:00 |
00:25:58.04 |
+28:46:16.4 |
HIP 2055 |
10.21 |
| 2026-07-31 12:00 |
00:25:57.06 |
+28:46:21.6 |
HIP 2055 |
10.15 |
| 2026-08-01 00:00 |
00:25:56.07 |
+28:46:26.6 |
HIP 2055 |
10.09 |
| 2026-08-01 12:00 |
00:25:55.07 |
+28:46:31.6 |
HIP 2055 |
10.05 |
| 2026-08-02 00:00 |
00:25:54.05 |
+28:46:36.4 |
HIP 2055 |
10.01 |
| 2026-08-02 12:00 |
00:25:53.02 |
+28:46:41.1 |
HIP 2055 |
9.98 |
| 2026-08-03 00:00 |
00:25:51.98 |
+28:46:45.7 |
HIP 2055 |
9.95 |
| 2026-08-03 12:00 |
00:25:50.92 |
+28:46:50.2 |
HIP 2055 |
9.94 |
| 2026-08-04 00:00 |
00:25:49.84 |
+28:46:54.5 |
HIP 2055 |
9.93 |
| 2026-08-04 12:00 |
00:25:48.76 |
+28:46:58.7 |
HIP 2055 |
9.94 |
| 2026-08-05 00:00 |
00:25:47.66 |
+28:47:02.8 |
HIP 2055 |
9.95 |
| 2026-08-05 12:00 |
00:25:46.54 |
+28:47:06.7 |
HIP 2055 |
9.97 |
| 2026-08-06 00:00 |
00:25:45.42 |
+28:47:10.6 |
HIP 2055 |
10.00 |
| 2026-08-06 12:00 |
00:25:44.28 |
+28:47:14.2 |
HIP 2055 |
10.04 |
| 2026-08-07 00:00 |
00:25:43.12 |
+28:47:17.8 |
HIP 2055 |
10.09 |
| 2026-08-07 12:00 |
00:25:41.96 |
+28:47:21.3 |
HIP 2055 |
10.15 |
| 2026-08-08 00:00 |
00:25:40.78 |
+28:47:24.6 |
HIP 2055 |
10.22 |
| 2026-08-08 12:00 |
00:25:39.58 |
+28:47:27.8 |
HIP 2055 |
10.30 |
| 2026-08-09 00:00 |
00:25:38.37 |
+28:47:30.8 |
HIP 2055 |
10.39 |
| 2026-08-09 12:00 |
00:25:37.15 |
+28:47:33.7 |
HIP 2055 |
10.49 |
| 2026-08-10 00:00 |
00:25:35.92 |
+28:47:36.5 |
HIP 2055 |
10.60 |
| 2026-08-10 12:00 |
00:25:34.68 |
+28:47:39.2 |
HIP 2055 |
10.71 |
| 2026-08-11 00:00 |
00:25:33.42 |
+28:47:41.7 |
HIP 2055 |
10.84 |
| 2026-08-11 12:00 |
00:25:32.15 |
+28:47:44.1 |
HIP 2055 |
10.98 |
| 2026-08-12 00:00 |
00:25:30.86 |
+28:47:46.4 |
HIP 2055 |
11.12 |
| 2026-08-12 12:00 |
00:25:29.57 |
+28:47:48.5 |
HIP 2055 |
11.27 |
| 2026-08-13 00:00 |
00:25:28.26 |
+28:47:50.5 |
HIP 2055 |
11.43 |
| 2026-08-13 12:00 |
00:25:26.94 |
+28:47:52.4 |
HIP 2055 |
11.60 |
| 2026-08-14 00:00 |
00:25:25.60 |
+28:47:54.2 |
HIP 2055 |
11.78 |
| 2026-08-14 12:00 |
00:25:24.26 |
+28:47:55.8 |
HIP 2055 |
11.97 |
| 2026-08-15 00:00 |
00:25:22.90 |
+28:47:57.2 |
HIP 2055 |
12.16 |
| 2026-08-15 12:00 |
00:25:21.53 |
+28:47:58.6 |
HIP 2055 |
12.36 |
| 2026-08-16 00:00 |
00:25:20.15 |
+28:47:59.8 |
HIP 2055 |
12.57 |
| 2026-08-16 12:00 |
00:25:18.76 |
+28:48:00.9 |
HIP 2055 |
12.79 |
| 2026-08-17 00:00 |
00:25:17.36 |
+28:48:01.8 |
HIP 2055 |
13.01 |
| 2026-08-17 12:00 |
00:25:15.94 |
+28:48:02.6 |
HIP 2055 |
13.24 |
| 2026-08-18 00:00 |
00:25:14.52 |
+28:48:03.3 |
HIP 2055 |
13.47 |
| 2026-08-18 12:00 |
00:25:13.08 |
+28:48:03.8 |
HIP 2055 |
13.72 |
| 2026-08-19 00:00 |
00:25:11.63 |
+28:48:04.2 |
HIP 2055 |
13.97 |