C/2017 C1 (NEOWISE)
メタデータ
| 項目 |
値 |
| Designation |
C/2017 C1 (NEOWISE) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-01-18T22:42:46.506240Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:29Z |
| Obs used |
60 |
| NEO |
- |
| M1 |
18.100 |
| K1 |
8.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2017-03-06.0000000 |
| e |
0.92781552 |
| q (au) |
1.501755 |
| a (au) |
20.804403 |
| i (deg) |
65.752241 |
| Ω (om, deg) |
357.457191 |
| ω (w, deg) |
110.204316 |
| M (ma, deg) |
0.478338 |
等級
散乱 + 全体線形
$$
M_a = (17.436 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
17.436 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.703 |
| 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) |
| 2026-02-03 00:00 |
15:39:03.69 |
-86:54:54.1 |
HIP 77470 |
22.42 |
| 2026-02-03 12:00 |
15:39:35.74 |
-86:56:20.1 |
HIP 77470 |
20.92 |
| 2026-02-04 00:00 |
15:40:07.36 |
-86:57:46.2 |
HIP 77470 |
19.43 |
| 2026-02-04 12:00 |
15:40:38.56 |
-86:59:12.4 |
HIP 77470 |
17.94 |
| 2026-02-05 00:00 |
15:41:09.32 |
-87:00:38.6 |
HIP 77470 |
16.45 |
| 2026-02-05 12:00 |
15:41:39.62 |
-87:02:04.8 |
HIP 77470 |
14.97 |
| 2026-02-06 00:00 |
15:42:09.46 |
-87:03:31.1 |
HIP 77470 |
13.49 |
| 2026-02-06 12:00 |
15:42:38.83 |
-87:04:57.3 |
HIP 77470 |
12.01 |
| 2026-02-07 00:00 |
15:43:07.70 |
-87:06:23.7 |
HIP 77470 |
10.55 |
| 2026-02-07 12:00 |
15:43:36.06 |
-87:07:50.0 |
HIP 77470 |
9.09 |
| 2026-02-08 00:00 |
15:44:03.91 |
-87:09:16.4 |
HIP 77470 |
7.65 |
| 2026-02-08 12:00 |
15:44:31.22 |
-87:10:42.8 |
HIP 77470 |
6.23 |
| 2026-02-09 00:00 |
15:44:57.98 |
-87:12:09.2 |
HIP 77470 |
4.85 |
| 2026-02-09 12:00 |
15:45:24.17 |
-87:13:35.7 |
HIP 77470 |
3.57 |
| 2026-02-10 00:00 |
15:45:49.79 |
-87:15:02.1 |
HIP 77470 |
2.52 |
| 2026-02-10 12:00 |
15:46:14.80 |
-87:16:28.6 |
HIP 77470 |
2.08 |
| 2026-02-11 00:00 |
15:46:39.20 |
-87:17:55.1 |
HIP 77470 |
2.59 |
| 2026-02-11 12:00 |
15:47:02.96 |
-87:19:21.6 |
HIP 77470 |
3.67 |
| 2026-02-12 00:00 |
15:47:26.07 |
-87:20:48.1 |
HIP 77470 |
4.95 |
| 2026-02-12 12:00 |
15:47:48.50 |
-87:22:14.6 |
HIP 77470 |
6.32 |
| 2026-02-13 00:00 |
15:48:10.24 |
-87:23:41.1 |
HIP 77470 |
7.72 |
| 2026-02-13 12:00 |
15:48:31.27 |
-87:25:07.5 |
HIP 77470 |
9.15 |
| 2026-02-14 00:00 |
15:48:51.57 |
-87:26:34.0 |
HIP 77470 |
10.58 |
| 2026-02-14 12:00 |
15:49:11.10 |
-87:28:00.5 |
HIP 77470 |
12.02 |
| 2026-02-15 00:00 |
15:49:29.86 |
-87:29:26.9 |
HIP 77470 |
13.47 |
| 2026-02-15 12:00 |
15:49:47.81 |
-87:30:53.3 |
HIP 77470 |
14.91 |
| 2026-02-16 00:00 |
15:50:04.93 |
-87:32:19.7 |
HIP 77114 |
14.63 |
| 2026-02-16 12:00 |
15:50:21.20 |
-87:33:46.1 |
HIP 77114 |
13.26 |
| 2026-02-17 00:00 |
15:50:36.59 |
-87:35:12.4 |
HIP 77114 |
11.92 |
| 2026-02-17 12:00 |
15:50:51.07 |
-87:36:38.7 |
HIP 77114 |
10.60 |
| 2026-02-18 00:00 |
15:51:04.61 |
-87:38:05.0 |
HIP 77114 |
9.31 |
| 2026-02-18 12:00 |
15:51:17.19 |
-87:39:31.2 |
HIP 77114 |
8.07 |
| 2026-02-19 00:00 |
15:51:28.78 |
-87:40:57.3 |
HIP 77114 |
6.91 |
| 2026-02-19 12:00 |
15:51:39.34 |
-87:42:23.4 |
HIP 77114 |
5.85 |
| 2026-02-20 00:00 |
15:51:48.83 |
-87:43:49.5 |
HIP 77114 |
4.99 |
| 2026-02-20 12:00 |
15:51:57.24 |
-87:45:15.4 |
HIP 77114 |
4.42 |
| 2026-02-21 00:00 |
15:52:04.52 |
-87:46:41.3 |
HIP 77114 |
4.26 |
| 2026-02-21 12:00 |
15:52:10.63 |
-87:48:07.2 |
HIP 77114 |
4.56 |
| 2026-02-22 00:00 |
15:52:15.55 |
-87:49:32.9 |
HIP 77114 |
5.24 |
| 2026-02-22 12:00 |
15:52:19.22 |
-87:50:58.6 |
HIP 77114 |
6.17 |
| 2026-02-23 00:00 |
15:52:21.62 |
-87:52:24.1 |
HIP 77114 |
7.25 |
| 2026-02-23 12:00 |
15:52:22.69 |
-87:53:49.6 |
HIP 77114 |
8.43 |
| 2026-02-24 00:00 |
15:52:22.40 |
-87:55:14.9 |
HIP 77114 |
9.67 |