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) |
| 2026-09-20 00:00 |
23:12:19.78 |
-59:49:49.1 |
HIP 114820 |
25.34 |
| 2026-09-20 12:00 |
23:12:04.13 |
-59:49:42.6 |
HIP 114270 |
26.58 |
| 2026-09-21 00:00 |
23:11:48.52 |
-59:49:35.1 |
HIP 114270 |
24.63 |
| 2026-09-21 12:00 |
23:11:32.93 |
-59:49:26.7 |
HIP 114270 |
22.69 |
| 2026-09-22 00:00 |
23:11:17.39 |
-59:49:17.3 |
HIP 114270 |
20.75 |
| 2026-09-22 12:00 |
23:11:01.88 |
-59:49:07.0 |
HIP 114270 |
18.82 |
| 2026-09-23 00:00 |
23:10:46.41 |
-59:48:55.8 |
HIP 114270 |
16.90 |
| 2026-09-23 12:00 |
23:10:30.99 |
-59:48:43.6 |
HIP 114270 |
14.98 |
| 2026-09-24 00:00 |
23:10:15.60 |
-59:48:30.5 |
HIP 114270 |
13.08 |
| 2026-09-24 12:00 |
23:10:00.26 |
-59:48:16.5 |
HIP 114270 |
11.19 |
| 2026-09-25 00:00 |
23:09:44.97 |
-59:48:01.5 |
HIP 114270 |
9.32 |
| 2026-09-25 12:00 |
23:09:29.72 |
-59:47:45.6 |
HIP 114270 |
7.48 |
| 2026-09-26 00:00 |
23:09:14.52 |
-59:47:28.7 |
HIP 114270 |
5.70 |
| 2026-09-26 12:00 |
23:08:59.36 |
-59:47:11.0 |
HIP 114270 |
4.07 |
| 2026-09-27 00:00 |
23:08:44.26 |
-59:46:52.3 |
HIP 114270 |
2.82 |
| 2026-09-27 12:00 |
23:08:29.21 |
-59:46:32.7 |
HIP 114267 |
2.58 |
| 2026-09-28 00:00 |
23:08:14.21 |
-59:46:12.2 |
HIP 114267 |
3.44 |
| 2026-09-28 12:00 |
23:07:59.27 |
-59:45:50.7 |
HIP 114267 |
4.92 |
| 2026-09-29 00:00 |
23:07:44.38 |
-59:45:28.4 |
HIP 114267 |
6.62 |
| 2026-09-29 12:00 |
23:07:29.55 |
-59:45:05.1 |
HIP 114198 |
7.11 |
| 2026-09-30 00:00 |
23:07:14.78 |
-59:44:40.9 |
HIP 114198 |
7.18 |
| 2026-09-30 12:00 |
23:07:00.06 |
-59:44:15.8 |
HIP 114198 |
7.72 |
| 2026-10-01 00:00 |
23:06:45.41 |
-59:43:49.8 |
HIP 114198 |
8.64 |
| 2026-10-01 12:00 |
23:06:30.82 |
-59:43:22.9 |
HIP 114198 |
9.83 |
| 2026-10-02 00:00 |
23:06:16.29 |
-59:42:55.1 |
HIP 114198 |
11.20 |
| 2026-10-02 12:00 |
23:06:01.82 |
-59:42:26.4 |
HIP 114198 |
12.69 |
| 2026-10-03 00:00 |
23:05:47.42 |
-59:41:56.8 |
HIP 114198 |
14.27 |
| 2026-10-03 12:00 |
23:05:33.09 |
-59:41:26.3 |
HIP 114198 |
15.90 |
| 2026-10-04 00:00 |
23:05:18.82 |
-59:40:54.9 |
HIP 113885 |
14.87 |
| 2026-10-04 12:00 |
23:05:04.63 |
-59:40:22.6 |
HIP 113885 |
13.20 |
| 2026-10-05 00:00 |
23:04:50.50 |
-59:39:49.5 |
HIP 113885 |
11.58 |
| 2026-10-05 12:00 |
23:04:36.45 |
-59:39:15.4 |
HIP 113885 |
10.05 |
| 2026-10-06 00:00 |
23:04:22.47 |
-59:38:40.5 |
HIP 113885 |
8.64 |
| 2026-10-06 12:00 |
23:04:08.56 |
-59:38:04.7 |
HIP 113885 |
7.42 |
| 2026-10-07 00:00 |
23:03:54.73 |
-59:37:28.0 |
HIP 113885 |
6.50 |
| 2026-10-07 12:00 |
23:03:40.98 |
-59:36:50.5 |
HIP 113885 |
6.01 |
| 2026-10-08 00:00 |
23:03:27.30 |
-59:36:12.1 |
HIP 113885 |
6.04 |
| 2026-10-08 12:00 |
23:03:13.71 |
-59:35:32.8 |
HIP 113885 |
6.60 |
| 2026-10-09 00:00 |
23:03:00.19 |
-59:34:52.6 |
HIP 113885 |
7.57 |
| 2026-10-09 12:00 |
23:02:46.75 |
-59:34:11.6 |
HIP 113735 |
8.53 |
| 2026-10-10 00:00 |
23:02:33.40 |
-59:33:29.8 |
HIP 113735 |
6.94 |
| 2026-10-10 12:00 |
23:02:20.13 |
-59:32:47.1 |
HIP 113735 |
5.49 |
| 2026-10-11 00:00 |
23:02:06.95 |
-59:32:03.6 |
HIP 113735 |
4.32 |