メタデータ
| 項目 |
値 |
| Designation |
C/2019 L2 (NEOWISE) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-04-02T01:58:42.522240Z |
| Orbit solution date (soln_date, UTC) |
2022-07-19T02:26:14Z |
| Obs used |
117 |
| NEO |
- |
| M1 |
10.400 |
| K1 |
27.750 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-06-11T18:48:21.312000Z |
| Discovery magnitude (MPC) |
18.00 R |
| Discovery observatory (MPC) |
C51 · WISE |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2019-07-05.0000000 |
| e |
0.93676409 |
| q (au) |
1.621540 |
| a (au) |
25.642708 |
| i (deg) |
152.187378 |
| Ω (om, deg) |
12.534296 |
| ω (w, deg) |
18.816880 |
| M (ma, deg) |
0.712861 |
等級
散乱 + 全体線形
$$
M_a = (13.141 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
13.141 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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) |
| 2026-09-20 00:00 |
13:18:16.20 |
-03:51:13.7 |
HIP 64731 |
33.37 |
| 2026-09-20 12:00 |
13:18:20.91 |
-03:51:49.5 |
HIP 64731 |
34.50 |
| 2026-09-21 00:00 |
13:18:25.64 |
-03:52:25.2 |
HIP 64731 |
35.63 |
| 2026-09-21 12:00 |
13:18:30.39 |
-03:53:01.0 |
HIP 64731 |
36.79 |
| 2026-09-22 00:00 |
13:18:35.15 |
-03:53:36.8 |
HIP 64731 |
37.96 |
| 2026-09-22 12:00 |
13:18:39.93 |
-03:54:12.7 |
HIP 64731 |
39.15 |
| 2026-09-23 00:00 |
13:18:44.73 |
-03:54:48.6 |
HIP 64731 |
40.34 |
| 2026-09-23 12:00 |
13:18:49.54 |
-03:55:24.5 |
HIP 64731 |
41.55 |
| 2026-09-24 00:00 |
13:18:54.37 |
-03:56:00.5 |
HIP 64731 |
42.78 |
| 2026-09-24 12:00 |
13:18:59.21 |
-03:56:36.5 |
HIP 64731 |
44.01 |
| 2026-09-25 00:00 |
13:19:04.06 |
-03:57:12.5 |
HIP 64731 |
45.25 |
| 2026-09-25 12:00 |
13:19:08.93 |
-03:57:48.5 |
HIP 64731 |
46.50 |
| 2026-09-26 00:00 |
13:19:13.82 |
-03:58:24.5 |
HIP 64731 |
47.77 |
| 2026-09-26 12:00 |
13:19:18.72 |
-03:59:00.6 |
HIP 64731 |
49.04 |
| 2026-09-27 00:00 |
13:19:23.63 |
-03:59:36.7 |
HIP 64731 |
50.31 |
| 2026-09-27 12:00 |
13:19:28.55 |
-04:00:12.8 |
HIP 64731 |
51.60 |
| 2026-09-28 00:00 |
13:19:33.49 |
-04:00:48.9 |
HIP 64731 |
52.89 |
| 2026-09-28 12:00 |
13:19:38.44 |
-04:01:25.1 |
HIP 65243 |
54.09 |
| 2026-09-29 00:00 |
13:19:43.40 |
-04:02:01.2 |
HIP 65243 |
52.79 |
| 2026-09-29 12:00 |
13:19:48.37 |
-04:02:37.4 |
HIP 65243 |
51.49 |
| 2026-09-30 00:00 |
13:19:53.35 |
-04:03:13.5 |
HIP 65243 |
50.20 |
| 2026-09-30 12:00 |
13:19:58.35 |
-04:03:49.7 |
HIP 65243 |
48.91 |
| 2026-10-01 00:00 |
13:20:03.36 |
-04:04:25.8 |
HIP 65243 |
47.62 |
| 2026-10-01 12:00 |
13:20:08.37 |
-04:05:02.0 |
HIP 65243 |
46.34 |
| 2026-10-02 00:00 |
13:20:13.40 |
-04:05:38.1 |
HIP 65243 |
45.06 |
| 2026-10-02 12:00 |
13:20:18.43 |
-04:06:14.3 |
HIP 65243 |
43.79 |
| 2026-10-03 00:00 |
13:20:23.48 |
-04:06:50.4 |
HIP 65243 |
42.52 |
| 2026-10-03 12:00 |
13:20:28.53 |
-04:07:26.5 |
HIP 65243 |
41.26 |
| 2026-10-04 00:00 |
13:20:33.60 |
-04:08:02.7 |
HIP 65243 |
40.01 |
| 2026-10-04 12:00 |
13:20:38.67 |
-04:08:38.8 |
HIP 65243 |
38.77 |
| 2026-10-05 00:00 |
13:20:43.75 |
-04:09:14.9 |
HIP 65243 |
37.54 |
| 2026-10-05 12:00 |
13:20:48.83 |
-04:09:50.9 |
HIP 65243 |
36.32 |
| 2026-10-06 00:00 |
13:20:53.93 |
-04:10:27.0 |
HIP 65243 |
35.11 |
| 2026-10-06 12:00 |
13:20:59.03 |
-04:11:03.0 |
HIP 65243 |
33.92 |
| 2026-10-07 00:00 |
13:21:04.14 |
-04:11:39.0 |
HIP 65243 |
32.74 |
| 2026-10-07 12:00 |
13:21:09.25 |
-04:12:15.0 |
HIP 65243 |
31.58 |
| 2026-10-08 00:00 |
13:21:14.37 |
-04:12:50.9 |
HIP 65243 |
30.44 |
| 2026-10-08 12:00 |
13:21:19.49 |
-04:13:26.8 |
HIP 65243 |
29.33 |
| 2026-10-09 00:00 |
13:21:24.62 |
-04:14:02.7 |
HIP 65243 |
28.24 |
| 2026-10-09 12:00 |
13:21:29.76 |
-04:14:38.6 |
HIP 65243 |
27.18 |
| 2026-10-10 00:00 |
13:21:34.89 |
-04:15:14.3 |
HIP 65243 |
26.16 |
| 2026-10-10 12:00 |
13:21:40.04 |
-04:15:50.1 |
HIP 65243 |
25.18 |
| 2026-10-11 00:00 |
13:21:45.18 |
-04:16:25.8 |
HIP 65243 |
24.23 |