メタデータ
| 項目 |
値 |
| Designation |
C/2016 C2 (NEOWISE) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2016-04-19T14:19:31.131840Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:23Z |
| Obs used |
148 |
| NEO |
- |
| M1 |
13.800 |
| K1 |
20.750 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2016-03-12.0000000 |
| e |
0.97563583 |
| q (au) |
1.559754 |
| a (au) |
64.018322 |
| i (deg) |
38.156610 |
| Ω (om, deg) |
24.404634 |
| ω (w, deg) |
214.403353 |
| M (ma, deg) |
359.925732 |
等級
散乱 + 全体線形
$$
M_a = (14.251 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
14.251 |
| 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) |
| 2026-05-12 00:00 |
01:49:43.02 |
+16:00:48.5 |
HIP 8414 |
24.26 |
| 2026-05-12 12:00 |
01:49:47.53 |
+16:01:18.6 |
HIP 8414 |
24.67 |
| 2026-05-13 00:00 |
01:49:52.03 |
+16:01:48.7 |
HIP 8448 |
24.99 |
| 2026-05-13 12:00 |
01:49:56.51 |
+16:02:18.8 |
HIP 8448 |
25.19 |
| 2026-05-14 00:00 |
01:50:00.97 |
+16:02:48.8 |
HIP 8448 |
25.45 |
| 2026-05-14 12:00 |
01:50:05.42 |
+16:03:18.7 |
HIP 8448 |
25.75 |
| 2026-05-15 00:00 |
01:50:09.86 |
+16:03:48.7 |
HIP 8448 |
26.11 |
| 2026-05-15 12:00 |
01:50:14.28 |
+16:04:18.6 |
HIP 8448 |
26.51 |
| 2026-05-16 00:00 |
01:50:18.68 |
+16:04:48.4 |
HIP 8448 |
26.95 |
| 2026-05-16 12:00 |
01:50:23.07 |
+16:05:18.2 |
HIP 8667 |
25.94 |
| 2026-05-17 00:00 |
01:50:27.44 |
+16:05:47.9 |
HIP 8667 |
24.85 |
| 2026-05-17 12:00 |
01:50:31.80 |
+16:06:17.6 |
HIP 8667 |
23.78 |
| 2026-05-18 00:00 |
01:50:36.14 |
+16:06:47.2 |
HIP 8667 |
22.72 |
| 2026-05-18 12:00 |
01:50:40.46 |
+16:07:16.8 |
HIP 8667 |
21.67 |
| 2026-05-19 00:00 |
01:50:44.76 |
+16:07:46.3 |
HIP 8667 |
20.64 |
| 2026-05-19 12:00 |
01:50:49.05 |
+16:08:15.8 |
HIP 8667 |
19.62 |
| 2026-05-20 00:00 |
01:50:53.32 |
+16:08:45.2 |
HIP 8667 |
18.62 |
| 2026-05-20 12:00 |
01:50:57.57 |
+16:09:14.5 |
HIP 8667 |
17.64 |
| 2026-05-21 00:00 |
01:51:01.80 |
+16:09:43.8 |
HIP 8667 |
16.68 |
| 2026-05-21 12:00 |
01:51:06.01 |
+16:10:13.0 |
HIP 8667 |
15.75 |
| 2026-05-22 00:00 |
01:51:10.20 |
+16:10:42.2 |
HIP 8667 |
14.84 |
| 2026-05-22 12:00 |
01:51:14.37 |
+16:11:11.2 |
HIP 8667 |
13.97 |
| 2026-05-23 00:00 |
01:51:18.53 |
+16:11:40.2 |
HIP 8667 |
13.14 |
| 2026-05-23 12:00 |
01:51:22.66 |
+16:12:09.2 |
HIP 8667 |
12.36 |
| 2026-05-24 00:00 |
01:51:26.78 |
+16:12:38.1 |
HIP 8667 |
11.63 |
| 2026-05-24 12:00 |
01:51:30.87 |
+16:13:06.8 |
HIP 8667 |
10.96 |
| 2026-05-25 00:00 |
01:51:34.94 |
+16:13:35.6 |
HIP 8667 |
10.37 |
| 2026-05-25 12:00 |
01:51:38.99 |
+16:14:04.2 |
HIP 8667 |
9.86 |
| 2026-05-26 00:00 |
01:51:43.03 |
+16:14:32.8 |
HIP 8667 |
9.46 |
| 2026-05-26 12:00 |
01:51:47.04 |
+16:15:01.3 |
HIP 8667 |
9.16 |
| 2026-05-27 00:00 |
01:51:51.02 |
+16:15:29.7 |
HIP 8667 |
8.98 |
| 2026-05-27 12:00 |
01:51:54.99 |
+16:15:58.0 |
HIP 8667 |
8.92 |
| 2026-05-28 00:00 |
01:51:58.94 |
+16:16:26.3 |
HIP 8667 |
8.99 |
| 2026-05-28 12:00 |
01:52:02.86 |
+16:16:54.4 |
HIP 8667 |
9.18 |
| 2026-05-29 00:00 |
01:52:06.76 |
+16:17:22.5 |
HIP 8667 |
9.48 |
| 2026-05-29 12:00 |
01:52:10.64 |
+16:17:50.5 |
HIP 8667 |
9.87 |
| 2026-05-30 00:00 |
01:52:14.49 |
+16:18:18.4 |
HIP 8667 |
10.36 |
| 2026-05-30 12:00 |
01:52:18.32 |
+16:18:46.2 |
HIP 8667 |
10.91 |
| 2026-05-31 00:00 |
01:52:22.13 |
+16:19:13.9 |
HIP 8667 |
11.53 |
| 2026-05-31 12:00 |
01:52:25.91 |
+16:19:41.6 |
HIP 8667 |
12.20 |
| 2026-06-01 00:00 |
01:52:29.68 |
+16:20:09.1 |
HIP 8667 |
12.90 |
| 2026-06-01 12:00 |
01:52:33.41 |
+16:20:36.6 |
HIP 8667 |
13.64 |
| 2026-06-02 00:00 |
01:52:37.13 |
+16:21:03.9 |
HIP 8667 |
14.41 |