メタデータ
| 項目 |
値 |
| Designation |
C/1987 W2 (Furuyama) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1988-03-03T01:38:49.009920Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:36Z |
| Obs used |
152 |
| NEO |
- |
| M1 |
9.400 |
| 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) |
1988-01-12.0000000 |
| e |
1.00023007 |
| q (au) |
1.679522 |
| a (au) |
-7299.904944 |
| i (deg) |
117.781967 |
| Ω (om, deg) |
250.752559 |
| ω (w, deg) |
233.626815 |
| M (ma, deg) |
-0.000081 |
等級
散乱 + 全体線形
$$
M_a = (4.823 + 5.789\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
4.823 |
| n |
5.789 |
| gf |
1.000 |
| gb |
-0.950 |
| k |
1.000 |
| 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) |
| 2026-05-12 00:00 |
15:52:33.58 |
+11:16:04.6 |
HIP 77847 |
19.16 |
| 2026-05-12 12:00 |
15:52:31.68 |
+11:16:13.0 |
HIP 77847 |
19.49 |
| 2026-05-13 00:00 |
15:52:29.78 |
+11:16:21.3 |
HIP 77847 |
19.83 |
| 2026-05-13 12:00 |
15:52:27.88 |
+11:16:29.5 |
HIP 77847 |
20.18 |
| 2026-05-14 00:00 |
15:52:25.98 |
+11:16:37.5 |
HIP 77847 |
20.53 |
| 2026-05-14 12:00 |
15:52:24.07 |
+11:16:45.4 |
HIP 77847 |
20.89 |
| 2026-05-15 00:00 |
15:52:22.16 |
+11:16:53.2 |
HIP 77847 |
21.26 |
| 2026-05-15 12:00 |
15:52:20.25 |
+11:17:00.9 |
HIP 77847 |
21.63 |
| 2026-05-16 00:00 |
15:52:18.34 |
+11:17:08.4 |
HIP 77847 |
22.01 |
| 2026-05-16 12:00 |
15:52:16.43 |
+11:17:15.9 |
HIP 77847 |
22.40 |
| 2026-05-17 00:00 |
15:52:14.51 |
+11:17:23.2 |
HIP 77847 |
22.79 |
| 2026-05-17 12:00 |
15:52:12.60 |
+11:17:30.3 |
HIP 77847 |
23.18 |
| 2026-05-18 00:00 |
15:52:10.68 |
+11:17:37.4 |
HIP 77847 |
23.58 |
| 2026-05-18 12:00 |
15:52:08.76 |
+11:17:44.3 |
HIP 77847 |
23.98 |
| 2026-05-19 00:00 |
15:52:06.84 |
+11:17:51.1 |
HIP 77847 |
24.38 |
| 2026-05-19 12:00 |
15:52:04.93 |
+11:17:57.7 |
HIP 77847 |
24.79 |
| 2026-05-20 00:00 |
15:52:03.01 |
+11:18:04.3 |
HIP 77597 |
24.73 |
| 2026-05-20 12:00 |
15:52:01.09 |
+11:18:10.7 |
HIP 77597 |
24.26 |
| 2026-05-21 00:00 |
15:51:59.17 |
+11:18:17.0 |
HIP 77597 |
23.80 |
| 2026-05-21 12:00 |
15:51:57.25 |
+11:18:23.1 |
HIP 77597 |
23.33 |
| 2026-05-22 00:00 |
15:51:55.33 |
+11:18:29.2 |
HIP 77597 |
22.86 |
| 2026-05-22 12:00 |
15:51:53.41 |
+11:18:35.0 |
HIP 77597 |
22.40 |
| 2026-05-23 00:00 |
15:51:51.49 |
+11:18:40.8 |
HIP 77597 |
21.94 |
| 2026-05-23 12:00 |
15:51:49.57 |
+11:18:46.4 |
HIP 77597 |
21.48 |
| 2026-05-24 00:00 |
15:51:47.66 |
+11:18:52.0 |
HIP 77597 |
21.02 |
| 2026-05-24 12:00 |
15:51:45.74 |
+11:18:57.3 |
HIP 77597 |
20.56 |
| 2026-05-25 00:00 |
15:51:43.82 |
+11:19:02.6 |
HIP 77597 |
20.11 |
| 2026-05-25 12:00 |
15:51:41.91 |
+11:19:07.7 |
HIP 77597 |
19.66 |
| 2026-05-26 00:00 |
15:51:40.00 |
+11:19:12.7 |
HIP 77597 |
19.21 |
| 2026-05-26 12:00 |
15:51:38.09 |
+11:19:17.5 |
HIP 77597 |
18.76 |
| 2026-05-27 00:00 |
15:51:36.18 |
+11:19:22.3 |
HIP 77597 |
18.32 |
| 2026-05-27 12:00 |
15:51:34.27 |
+11:19:26.9 |
HIP 77597 |
17.88 |
| 2026-05-28 00:00 |
15:51:32.36 |
+11:19:31.3 |
HIP 77597 |
17.44 |
| 2026-05-28 12:00 |
15:51:30.46 |
+11:19:35.6 |
HIP 77597 |
17.01 |
| 2026-05-29 00:00 |
15:51:28.56 |
+11:19:39.8 |
HIP 77597 |
16.58 |
| 2026-05-29 12:00 |
15:51:26.66 |
+11:19:43.9 |
HIP 77597 |
16.16 |
| 2026-05-30 00:00 |
15:51:24.76 |
+11:19:47.8 |
HIP 77597 |
15.74 |
| 2026-05-30 12:00 |
15:51:22.86 |
+11:19:51.7 |
HIP 77597 |
15.32 |
| 2026-05-31 00:00 |
15:51:20.97 |
+11:19:55.3 |
HIP 77597 |
14.91 |
| 2026-05-31 12:00 |
15:51:19.08 |
+11:19:58.9 |
HIP 77597 |
14.50 |
| 2026-06-01 00:00 |
15:51:17.20 |
+11:20:02.3 |
HIP 77597 |
14.10 |
| 2026-06-01 12:00 |
15:51:15.31 |
+11:20:05.5 |
HIP 77597 |
13.71 |
| 2026-06-02 00:00 |
15:51:13.43 |
+11:20:08.7 |
HIP 77597 |
13.32 |