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) |
| 2026-07-29 00:00 |
11:16:03.91 |
+05:51:49.2 |
HIP 54904 |
24.00 |
| 2026-07-29 12:00 |
11:16:05.16 |
+05:51:41.0 |
HIP 54904 |
24.34 |
| 2026-07-30 00:00 |
11:16:06.42 |
+05:51:32.8 |
HIP 54904 |
24.68 |
| 2026-07-30 12:00 |
11:16:07.68 |
+05:51:24.5 |
HIP 54904 |
25.02 |
| 2026-07-31 00:00 |
11:16:08.96 |
+05:51:16.2 |
HIP 54904 |
25.37 |
| 2026-07-31 12:00 |
11:16:10.24 |
+05:51:07.8 |
HIP 54904 |
25.71 |
| 2026-08-01 00:00 |
11:16:11.53 |
+05:50:59.3 |
HIP 54904 |
26.06 |
| 2026-08-01 12:00 |
11:16:12.84 |
+05:50:50.8 |
HIP 54904 |
26.42 |
| 2026-08-02 00:00 |
11:16:14.15 |
+05:50:42.3 |
HIP 54904 |
26.77 |
| 2026-08-02 12:00 |
11:16:15.47 |
+05:50:33.7 |
HIP 54904 |
27.13 |
| 2026-08-03 00:00 |
11:16:16.80 |
+05:50:25.0 |
HIP 54904 |
27.49 |
| 2026-08-03 12:00 |
11:16:18.13 |
+05:50:16.3 |
HIP 54904 |
27.85 |
| 2026-08-04 00:00 |
11:16:19.48 |
+05:50:07.5 |
HIP 54904 |
28.21 |
| 2026-08-04 12:00 |
11:16:20.83 |
+05:49:58.7 |
HIP 54904 |
28.58 |
| 2026-08-05 00:00 |
11:16:22.20 |
+05:49:49.9 |
HIP 54904 |
28.95 |
| 2026-08-05 12:00 |
11:16:23.57 |
+05:49:41.0 |
HIP 54904 |
29.32 |
| 2026-08-06 00:00 |
11:16:24.95 |
+05:49:32.0 |
HIP 54904 |
29.69 |
| 2026-08-06 12:00 |
11:16:26.33 |
+05:49:23.0 |
HIP 54904 |
30.07 |
| 2026-08-07 00:00 |
11:16:27.73 |
+05:49:14.0 |
HIP 54904 |
30.45 |
| 2026-08-07 12:00 |
11:16:29.13 |
+05:49:04.9 |
HIP 54904 |
30.83 |
| 2026-08-08 00:00 |
11:16:30.54 |
+05:48:55.7 |
HIP 54904 |
31.21 |
| 2026-08-08 12:00 |
11:16:31.96 |
+05:48:46.5 |
HIP 54904 |
31.59 |
| 2026-08-09 00:00 |
11:16:33.39 |
+05:48:37.3 |
HIP 54904 |
31.98 |
| 2026-08-09 12:00 |
11:16:34.82 |
+05:48:28.0 |
HIP 54904 |
32.37 |
| 2026-08-10 00:00 |
11:16:36.26 |
+05:48:18.7 |
HIP 54904 |
32.76 |
| 2026-08-10 12:00 |
11:16:37.71 |
+05:48:09.3 |
HIP 54904 |
33.15 |
| 2026-08-11 00:00 |
11:16:39.17 |
+05:48:00.0 |
HIP 54904 |
33.54 |
| 2026-08-11 12:00 |
11:16:40.63 |
+05:47:50.5 |
HIP 54904 |
33.94 |
| 2026-08-12 00:00 |
11:16:42.10 |
+05:47:41.0 |
HIP 54904 |
34.34 |
| 2026-08-12 12:00 |
11:16:43.58 |
+05:47:31.4 |
HIP 54904 |
34.74 |
| 2026-08-13 00:00 |
11:16:45.06 |
+05:47:21.9 |
HIP 54904 |
35.14 |
| 2026-08-13 12:00 |
11:16:46.56 |
+05:47:12.3 |
HIP 54904 |
35.54 |
| 2026-08-14 00:00 |
11:16:48.05 |
+05:47:02.6 |
HIP 54904 |
35.95 |
| 2026-08-14 12:00 |
11:16:49.56 |
+05:46:52.9 |
HIP 54904 |
36.35 |
| 2026-08-15 00:00 |
11:16:51.07 |
+05:46:43.2 |
HIP 54904 |
36.76 |
| 2026-08-15 12:00 |
11:16:52.58 |
+05:46:33.5 |
HIP 54904 |
37.17 |
| 2026-08-16 00:00 |
11:16:54.11 |
+05:46:23.7 |
HIP 54904 |
37.58 |
| 2026-08-16 12:00 |
11:16:55.63 |
+05:46:13.9 |
HIP 54904 |
38.00 |
| 2026-08-17 00:00 |
11:16:57.17 |
+05:46:04.0 |
HIP 54904 |
38.41 |
| 2026-08-17 12:00 |
11:16:58.71 |
+05:45:54.1 |
HIP 54904 |
38.83 |
| 2026-08-18 00:00 |
11:17:00.25 |
+05:45:44.2 |
HIP 54904 |
39.25 |
| 2026-08-18 12:00 |
11:17:01.80 |
+05:45:34.2 |
HIP 54904 |
39.67 |
| 2026-08-19 00:00 |
11:17:03.36 |
+05:45:24.3 |
HIP 54904 |
40.09 |