メタデータ
| 項目 |
値 |
| Designation |
C/1987 B1 (Nishikawa-Takamizawa-Tago) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1987-03-17T08:17:23.208000Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:33Z |
| Obs used |
87 |
| NEO |
- |
| M1 |
7.500 |
| K1 |
5.750 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1987-02-26.0000000 |
| e |
0.99579827 |
| q (au) |
0.869588 |
| a (au) |
206.959563 |
| i (deg) |
172.229985 |
| Ω (om, deg) |
176.010516 |
| ω (w, deg) |
200.401841 |
| M (ma, deg) |
359.993596 |
等級
散乱 + 全体線形
$$
M_a = (6.240 + 4.361\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
6.240 |
| n |
4.361 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.996 |
| 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) |
| 2026-03-26 00:00 |
11:17:34.86 |
+05:43:45.6 |
HIP 55232 |
39.70 |
| 2026-03-26 12:00 |
11:17:33.09 |
+05:43:56.7 |
HIP 55232 |
40.05 |
| 2026-03-27 00:00 |
11:17:31.32 |
+05:44:07.9 |
HIP 55232 |
40.40 |
| 2026-03-27 12:00 |
11:17:29.56 |
+05:44:19.0 |
HIP 55232 |
40.75 |
| 2026-03-28 00:00 |
11:17:27.80 |
+05:44:30.0 |
HIP 55232 |
41.10 |
| 2026-03-28 12:00 |
11:17:26.05 |
+05:44:41.0 |
HIP 55232 |
41.45 |
| 2026-03-29 00:00 |
11:17:24.30 |
+05:44:52.0 |
HIP 55232 |
41.80 |
| 2026-03-29 12:00 |
11:17:22.56 |
+05:45:02.9 |
HIP 55232 |
42.16 |
| 2026-03-30 00:00 |
11:17:20.83 |
+05:45:13.8 |
HIP 55232 |
42.52 |
| 2026-03-30 12:00 |
11:17:19.10 |
+05:45:24.7 |
HIP 55232 |
42.87 |
| 2026-03-31 00:00 |
11:17:17.37 |
+05:45:35.5 |
HIP 55232 |
43.23 |
| 2026-03-31 12:00 |
11:17:15.65 |
+05:45:46.2 |
HIP 54904 |
42.84 |
| 2026-04-01 00:00 |
11:17:13.94 |
+05:45:56.9 |
HIP 54904 |
42.38 |
| 2026-04-01 12:00 |
11:17:12.23 |
+05:46:07.6 |
HIP 54904 |
41.92 |
| 2026-04-02 00:00 |
11:17:10.53 |
+05:46:18.3 |
HIP 54904 |
41.46 |
| 2026-04-02 12:00 |
11:17:08.84 |
+05:46:28.8 |
HIP 54904 |
41.01 |
| 2026-04-03 00:00 |
11:17:07.15 |
+05:46:39.4 |
HIP 54904 |
40.55 |
| 2026-04-03 12:00 |
11:17:05.47 |
+05:46:49.9 |
HIP 54904 |
40.10 |
| 2026-04-04 00:00 |
11:17:03.80 |
+05:47:00.3 |
HIP 54904 |
39.65 |
| 2026-04-04 12:00 |
11:17:02.13 |
+05:47:10.7 |
HIP 54904 |
39.20 |
| 2026-04-05 00:00 |
11:17:00.47 |
+05:47:21.1 |
HIP 54904 |
38.76 |
| 2026-04-05 12:00 |
11:16:58.82 |
+05:47:31.4 |
HIP 54904 |
38.31 |
| 2026-04-06 00:00 |
11:16:57.18 |
+05:47:41.6 |
HIP 54904 |
37.87 |
| 2026-04-06 12:00 |
11:16:55.54 |
+05:47:51.8 |
HIP 54904 |
37.43 |
| 2026-04-07 00:00 |
11:16:53.91 |
+05:48:01.9 |
HIP 54904 |
36.99 |
| 2026-04-07 12:00 |
11:16:52.28 |
+05:48:12.0 |
HIP 54904 |
36.56 |
| 2026-04-08 00:00 |
11:16:50.67 |
+05:48:22.1 |
HIP 54904 |
36.12 |
| 2026-04-08 12:00 |
11:16:49.06 |
+05:48:32.0 |
HIP 54904 |
35.69 |
| 2026-04-09 00:00 |
11:16:47.46 |
+05:48:42.0 |
HIP 54904 |
35.26 |
| 2026-04-09 12:00 |
11:16:45.87 |
+05:48:51.8 |
HIP 54904 |
34.84 |
| 2026-04-10 00:00 |
11:16:44.29 |
+05:49:01.7 |
HIP 54904 |
34.41 |
| 2026-04-10 12:00 |
11:16:42.71 |
+05:49:11.4 |
HIP 54904 |
33.99 |
| 2026-04-11 00:00 |
11:16:41.15 |
+05:49:21.1 |
HIP 54904 |
33.57 |
| 2026-04-11 12:00 |
11:16:39.59 |
+05:49:30.8 |
HIP 54904 |
33.15 |
| 2026-04-12 00:00 |
11:16:38.04 |
+05:49:40.3 |
HIP 54904 |
32.73 |
| 2026-04-12 12:00 |
11:16:36.50 |
+05:49:49.9 |
HIP 54904 |
32.32 |
| 2026-04-13 00:00 |
11:16:34.97 |
+05:49:59.3 |
HIP 54904 |
31.91 |
| 2026-04-13 12:00 |
11:16:33.44 |
+05:50:08.7 |
HIP 54904 |
31.50 |
| 2026-04-14 00:00 |
11:16:31.93 |
+05:50:18.1 |
HIP 54904 |
31.10 |
| 2026-04-14 12:00 |
11:16:30.43 |
+05:50:27.3 |
HIP 54904 |
30.69 |
| 2026-04-15 00:00 |
11:16:28.93 |
+05:50:36.6 |
HIP 54904 |
30.29 |
| 2026-04-15 12:00 |
11:16:27.44 |
+05:50:45.7 |
HIP 54904 |
29.89 |
| 2026-04-16 00:00 |
11:16:25.97 |
+05:50:54.8 |
HIP 54904 |
29.50 |