メタデータ
| 項目 |
値 |
| Designation |
C/2017 W2 (Leonard) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-11-01T22:30:18.835200Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:38Z |
| Obs used |
169 |
| NEO |
- |
| M1 |
10.900 |
| K1 |
10.000 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2017-12-26.0000000 |
| e |
0.71125672 |
| q (au) |
3.957327 |
| a (au) |
13.705348 |
| i (deg) |
98.179291 |
| Ω (om, deg) |
312.809062 |
| ω (w, deg) |
169.157714 |
| M (ma, deg) |
1.050179 |
等級
散乱 + 全体線形
$$
M_a = (10.278 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.278 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.700 |
| k |
0.800 |
| 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) |
| 2026-07-29 00:00 |
23:38:11.53 |
-58:39:31.6 |
HIP 116597 |
7.31 |
| 2026-07-29 12:00 |
23:38:00.29 |
-58:40:47.6 |
HIP 116597 |
5.59 |
| 2026-07-30 00:00 |
23:37:48.95 |
-58:42:03.3 |
HIP 116597 |
4.08 |
| 2026-07-30 12:00 |
23:37:37.52 |
-58:43:18.4 |
HIP 116597 |
3.10 |
| 2026-07-31 00:00 |
23:37:25.98 |
-58:44:33.1 |
HIP 116597 |
3.18 |
| 2026-07-31 12:00 |
23:37:14.35 |
-58:45:47.4 |
HIP 116597 |
4.29 |
| 2026-08-01 00:00 |
23:37:02.62 |
-58:47:01.1 |
HIP 116597 |
5.86 |
| 2026-08-01 12:00 |
23:36:50.79 |
-58:48:14.4 |
HIP 116597 |
7.62 |
| 2026-08-02 00:00 |
23:36:38.87 |
-58:49:27.2 |
HIP 116597 |
9.47 |
| 2026-08-02 12:00 |
23:36:26.86 |
-58:50:39.5 |
HIP 116597 |
11.36 |
| 2026-08-03 00:00 |
23:36:14.75 |
-58:51:51.2 |
HIP 116597 |
13.28 |
| 2026-08-03 12:00 |
23:36:02.54 |
-58:53:02.5 |
HIP 116597 |
15.22 |
| 2026-08-04 00:00 |
23:35:50.24 |
-58:54:13.2 |
HIP 116597 |
17.17 |
| 2026-08-04 12:00 |
23:35:37.85 |
-58:55:23.4 |
HIP 116288 |
18.03 |
| 2026-08-05 00:00 |
23:35:25.37 |
-58:56:33.1 |
HIP 116288 |
16.04 |
| 2026-08-05 12:00 |
23:35:12.80 |
-58:57:42.2 |
HIP 116288 |
14.06 |
| 2026-08-06 00:00 |
23:35:00.14 |
-58:58:50.7 |
HIP 116288 |
12.07 |
| 2026-08-06 12:00 |
23:34:47.39 |
-58:59:58.7 |
HIP 116288 |
10.08 |
| 2026-08-07 00:00 |
23:34:34.55 |
-59:01:06.1 |
HIP 116288 |
8.08 |
| 2026-08-07 12:00 |
23:34:21.63 |
-59:02:12.9 |
HIP 116288 |
6.08 |
| 2026-08-08 00:00 |
23:34:08.61 |
-59:03:19.1 |
HIP 116288 |
4.09 |
| 2026-08-08 12:00 |
23:33:55.52 |
-59:04:24.7 |
HIP 116288 |
2.10 |
| 2026-08-09 00:00 |
23:33:42.33 |
-59:05:29.8 |
HIP 116288 |
0.39 |
| 2026-08-09 12:00 |
23:33:29.07 |
-59:06:34.2 |
HIP 116288 |
2.00 |
| 2026-08-10 00:00 |
23:33:15.72 |
-59:07:37.9 |
HIP 116288 |
3.99 |
| 2026-08-10 12:00 |
23:33:02.29 |
-59:08:41.1 |
HIP 116288 |
6.00 |
| 2026-08-11 00:00 |
23:32:48.78 |
-59:09:43.6 |
HIP 116288 |
8.02 |
| 2026-08-11 12:00 |
23:32:35.19 |
-59:10:45.4 |
HIP 116288 |
10.04 |
| 2026-08-12 00:00 |
23:32:21.52 |
-59:11:46.6 |
HIP 116155 |
11.75 |
| 2026-08-12 12:00 |
23:32:07.78 |
-59:12:47.1 |
HIP 116155 |
12.57 |
| 2026-08-13 00:00 |
23:31:53.95 |
-59:13:47.0 |
HIP 116155 |
13.63 |
| 2026-08-13 12:00 |
23:31:40.06 |
-59:14:46.2 |
HIP 116155 |
14.89 |
| 2026-08-14 00:00 |
23:31:26.09 |
-59:15:44.6 |
HIP 116155 |
16.30 |
| 2026-08-14 12:00 |
23:31:12.04 |
-59:16:42.4 |
HIP 116155 |
17.83 |
| 2026-08-15 00:00 |
23:30:57.93 |
-59:17:39.5 |
HIP 115893 |
18.49 |
| 2026-08-15 12:00 |
23:30:43.75 |
-59:18:35.9 |
HIP 115893 |
16.45 |
| 2026-08-16 00:00 |
23:30:29.49 |
-59:19:31.5 |
HIP 115893 |
14.41 |
| 2026-08-16 12:00 |
23:30:15.17 |
-59:20:26.5 |
HIP 115893 |
12.37 |
| 2026-08-17 00:00 |
23:30:00.78 |
-59:21:20.7 |
HIP 115893 |
10.33 |
| 2026-08-17 12:00 |
23:29:46.33 |
-59:22:14.1 |
HIP 115893 |
8.28 |
| 2026-08-18 00:00 |
23:29:31.81 |
-59:23:06.8 |
HIP 115893 |
6.24 |
| 2026-08-18 12:00 |
23:29:17.23 |
-59:23:58.8 |
HIP 115893 |
4.20 |
| 2026-08-19 00:00 |
23:29:02.59 |
-59:24:50.0 |
HIP 115893 |
2.18 |